From 58212a258e8342daf47796e26441971d51823089 Mon Sep 17 00:00:00 2001
From: lz4 Upstream <kwrobot@kitware.com>
Date: Mon, 15 Oct 2018 16:02:03 -0400
Subject: [PATCH] lz4 2018-10-15 (e56db3f6)
Code extracted from:
https://gitlab.kitware.com/third-party/lz4.git
at commit e56db3f64a51deef26e3ee4b169f6543334d1de6 (for/vtk-20181015-1.8.3).
---
CMakeLists.txt | 18 +-
README.md | 53 +-
lib/README.md | 56 +-
lib/lz4.c | 1443 +++++++++++++++++++++++++++--------------
lib/lz4.h | 446 +++++++++----
lib/lz4frame.c | 445 ++++++++-----
lib/lz4frame.h | 268 ++++++--
lib/lz4frame_static.h | 104 +--
lib/lz4hc.c | 981 ++++++++++++++++++++++------
lib/lz4hc.h | 193 ++++--
lib/lz4opt.h | 366 -----------
lib/xxhash.c | 32 +-
12 files changed, 2774 insertions(+), 1631 deletions(-)
delete mode 100644 lib/lz4opt.h
diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6b186aa188..92246c565ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,24 +16,20 @@ set(CMAKE_CXX_VISIBILITY_PRESET hidden)
set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
set(CMAKE_C_STANDARD 99)
-vtk_add_library(vtklz4 ${sources} ${headers})
-if (NOT VTK_INSTALL_NO_DEVELOPMENT)
- install(FILES
- ${headers}
- DESTINATION "${VTK_INSTALL_INCLUDE_DIR}/vtklz4/lib"
- COMPONENT Development)
-endif()
-
-target_compile_definitions(vtklz4
+vtk_module_add_module(VTK::lz4
+ SOURCES ${sources}
+ HEADERS ${headers}
+ HEADERS_SUBDIR "vtklz4/lib")
+target_compile_definitions(lz4
PRIVATE
"LZ4_VERSION=\"1.8.0\"")
if (WIN32 AND BUILD_SHARED_LIBS)
- target_compile_definitions(vtklz4
+ target_compile_definitions(lz4
PRIVATE
LZ4_DLL_EXPORT=1
INTERFACE
LZ4_DLL_IMPORT=1)
endif ()
-target_include_directories(vtklz4
+target_include_directories(lz4
PRIVATE
"${CMAKE_CURRENT_SOURCE_DIR}/lib")
diff --git a/README.md b/README.md
index ec99630ef97..e64020d1c30 100644
--- a/README.md
+++ b/README.md
@@ -2,18 +2,23 @@ LZ4 - Extremely fast compression
================================
LZ4 is lossless compression algorithm,
-providing compression speed at 400 MB/s per core,
+providing compression speed > 500 MB/s per core,
scalable with multi-cores CPU.
It features an extremely fast decoder,
with speed in multiple GB/s per core,
typically reaching RAM speed limits on multi-core systems.
Speed can be tuned dynamically, selecting an "acceleration" factor
-which trades compression ratio for more speed up.
+which trades compression ratio for faster speed.
On the other end, a high compression derivative, LZ4_HC, is also provided,
trading CPU time for improved compression ratio.
All versions feature the same decompression speed.
+LZ4 is also compatible with [dictionary compression](https://github.com/facebook/zstd#the-case-for-small-data-compression),
+and can ingest any input file as dictionary,
+including those created by [Zstandard Dictionary Builder](https://github.com/facebook/zstd/blob/v1.3.5/programs/zstd.1.md#dictionary-builder).
+(note: only the final 64KB are used).
+
LZ4 library is provided as open-source software using BSD 2-Clause license.
@@ -43,33 +48,32 @@ Benchmarks
-------------------------
The benchmark uses [lzbench], from @inikep
-compiled with GCC v6.2.0 on Linux 64-bits.
-The reference system uses a Core i7-3930K CPU @ 4.5GHz.
+compiled with GCC v7.3.0 on Linux 64-bits (Debian 4.15.17-1).
+The reference system uses a Core i7-6700K CPU @ 4.0GHz.
Benchmark evaluates the compression of reference [Silesia Corpus]
in single-thread mode.
[lzbench]: https://github.com/inikep/lzbench
[Silesia Corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia
-| Compressor | Ratio | Compression | Decompression |
-| ---------- | ----- | ----------- | ------------- |
-| memcpy | 1.000 | 7300 MB/s | 7300 MB/s |
-|**LZ4 fast 8 (v1.7.3)**| 1.799 |**911 MB/s** | **3360 MB/s** |
-|**LZ4 default (v1.7.3)**|**2.101**|**625 MB/s** | **3220 MB/s** |
-| LZO 2.09 | 2.108 | 620 MB/s | 845 MB/s |
-| QuickLZ 1.5.0 | 2.238 | 510 MB/s | 600 MB/s |
-| Snappy 1.1.3 | 2.091 | 450 MB/s | 1550 MB/s |
-| LZF v3.6 | 2.073 | 365 MB/s | 820 MB/s |
-| [Zstandard] 1.1.1 -1 | 2.876 | 330 MB/s | 930 MB/s |
-| [Zstandard] 1.1.1 -3 | 3.164 | 200 MB/s | 810 MB/s |
-| [zlib] deflate 1.2.8 -1| 2.730 | 100 MB/s | 370 MB/s |
-|**LZ4 HC -9 (v1.7.3)** |**2.720**| 34 MB/s | **3240 MB/s** |
-| [zlib] deflate 1.2.8 -6| 3.099 | 33 MB/s | 390 MB/s |
+| Compressor | Ratio | Compression | Decompression |
+| ---------- | ----- | ----------- | ------------- |
+| memcpy | 1.000 |13100 MB/s | 13100 MB/s |
+|**LZ4 default (v1.8.2)** |**2.101**|**730 MB/s** | **3900 MB/s** |
+| LZO 2.09 | 2.108 | 630 MB/s | 800 MB/s |
+| QuickLZ 1.5.0 | 2.238 | 530 MB/s | 720 MB/s |
+| Snappy 1.1.4 | 2.091 | 525 MB/s | 1750 MB/s |
+| [Zstandard] 1.3.4 -1 | 2.877 | 470 MB/s | 1380 MB/s |
+| LZF v3.6 | 2.073 | 380 MB/s | 840 MB/s |
+| [zlib] deflate 1.2.11 -1| 2.730 | 100 MB/s | 380 MB/s |
+|**LZ4 HC -9 (v1.8.2)** |**2.721**| 40 MB/s | **3920 MB/s** |
+| [zlib] deflate 1.2.11 -6| 3.099 | 34 MB/s | 410 MB/s |
[zlib]: http://www.zlib.net/
[Zstandard]: http://www.zstd.net/
-LZ4 is also compatible and well optimized for x32 mode, for which it provides an additional +10% speed performance.
+LZ4 is also compatible and optimized for x32 mode,
+for which it provides additional speed performance.
Installation
@@ -77,11 +81,12 @@ Installation
```
make
-make install # this command may require root access
+make install # this command may require root permissions
```
LZ4's `Makefile` supports standard [Makefile conventions],
including [staged installs], [redirection], or [command redefinition].
+It is compatible with parallel builds (`-j#`).
[Makefile conventions]: https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
[staged installs]: https://www.gnu.org/prep/standards/html_node/DESTDIR.html
@@ -94,10 +99,10 @@ Documentation
The raw LZ4 block compression format is detailed within [lz4_Block_format].
-To compress an arbitrarily long file or data stream, multiple blocks are required.
-Organizing these blocks and providing a common header format to handle their content
-is the purpose of the Frame format, defined into [lz4_Frame_format].
-Interoperable versions of LZ4 must respect this frame format.
+Arbitrarily long files or data streams are compressed using multiple blocks,
+for streaming requirements. These blocks are organized into a frame,
+defined into [lz4_Frame_format].
+Interoperable versions of LZ4 must also respect the frame format.
[lz4_Block_format]: doc/lz4_Block_format.md
[lz4_Frame_format]: doc/lz4_Frame_format.md
diff --git a/lib/README.md b/lib/README.md
index b40442c4d36..7082fe3eeb1 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -1,44 +1,43 @@
LZ4 - Library Files
================================
-The directory contains many files, but depending on project's objectives,
+The `/lib` directory contains many files, but depending on project's objectives,
not all of them are necessary.
#### Minimal LZ4 build
The minimum required is **`lz4.c`** and **`lz4.h`**,
-which will provide the fast compression and decompression algorithm.
+which provides the fast compression and decompression algorithm.
+They generate and decode data using [LZ4 block format].
-#### The High Compression variant of LZ4
+#### High Compression variant
-For more compression at the cost of compression speed,
-the High Compression variant **lz4hc** is available.
-It's necessary to add **`lz4hc.c`** and **`lz4hc.h`**.
-The variant still depends on regular `lz4` source files.
-In particular, the decompression is still provided by `lz4.c`.
+For more compression ratio at the cost of compression speed,
+the High Compression variant called **lz4hc** is available.
+Add files **`lz4hc.c`** and **`lz4hc.h`**.
+The variant still depends on regular `lib/lz4.*` source files.
-#### Compatibility issues
+#### Frame variant, for interoperability
-In order to produce files or streams compatible with `lz4` command line utility,
+In order to produce compressed data compatible with `lz4` command line utility,
it's necessary to encode lz4-compressed blocks using the [official interoperable frame format].
This format is generated and decoded automatically by the **lz4frame** library.
-In order to work properly, lz4frame needs lz4 and lz4hc, and also **xxhash**,
-which provides error detection.
-(_Advanced stuff_ : It's possible to hide xxhash symbols into a local namespace.
-This is what `liblz4` does, to avoid symbol duplication
-in case a user program would link to several libraries containing xxhash symbols.)
+Its public API is described in `lib/lz4frame.h`.
+In order to work properly, lz4frame needs all other modules present in `/lib`,
+including, lz4 and lz4hc, and also **xxhash**.
+So it's necessary to include all `*.c` and `*.h` files present in `/lib`.
-#### Advanced API
+#### Advanced / Experimental API
-A more complex `lz4frame_static.h` is also provided.
-It contains definitions which are not guaranteed to remain stable within future versions.
-It must be used with static linking ***only***.
+A complex API defined in `lz4frame_static.h` contains definitions
+which are not guaranteed to remain stable in future versions.
+As a consequence, it must be used with static linking ***only***.
-#### Using MinGW+MSYS to create DLL
+#### Windows : using MinGW+MSYS to create DLL
DLL can be created using MinGW+MSYS with the `make liblz4` command.
This command creates `dll\liblz4.dll` and the import library `dll\liblz4.lib`.
@@ -51,23 +50,24 @@ file it should be linked with `dll\liblz4.dll`. For example:
```
gcc $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\liblz4.dll
```
-The compiled executable will require LZ4 DLL which is available at `dll\liblz4.dll`.
+The compiled executable will require LZ4 DLL which is available at `dll\liblz4.dll`.
-#### Miscellaneous
+#### Miscellaneous
Other files present in the directory are not source code. There are :
- - LICENSE : contains the BSD license text
- - Makefile : script to compile or install lz4 library (static or dynamic)
- - liblz4.pc.in : for pkg-config (make install)
- - README.md : this file
+ - `LICENSE` : contains the BSD license text
+ - `Makefile` : `make` script to compile and install lz4 library (static and dynamic)
+ - `liblz4.pc.in` : for `pkg-config` (used in `make install`)
+ - `README.md` : this file
[official interoperable frame format]: ../doc/lz4_Frame_format.md
+[LZ4 block format]: ../doc/lz4_Block_format.md
-#### License
+#### License
All source material within __lib__ directory are BSD 2-Clause licensed.
See [LICENSE](LICENSE) for details.
-The license is also repeated at the top of each source file.
+The license is also reminded at the top of each source file.
diff --git a/lib/lz4.c b/lib/lz4.c
index 8aea47be962..4046102e6de 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1,6 +1,6 @@
/*
LZ4 - Fast LZ compression algorithm
- Copyright (C) 2011-2017, Yann Collet.
+ Copyright (C) 2011-present, Yann Collet.
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
@@ -69,7 +69,9 @@
* Prefer these methods in priority order (0 > 1 > 2)
*/
#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */
-# if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
+# if defined(__GNUC__) && \
+ ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) \
+ || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
# define LZ4_FORCE_MEMORY_ACCESS 2
# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || defined(__GNUC__)
# define LZ4_FORCE_MEMORY_ACCESS 1
@@ -80,14 +82,17 @@
* LZ4_FORCE_SW_BITCOUNT
* Define this parameter if your target system or compiler does not support hardware bit count
*/
-#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for Windows CE does not support Hardware bit count */
+#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for WinCE doesn't support Hardware bit count */
# define LZ4_FORCE_SW_BITCOUNT
#endif
+
/*-************************************
* Dependency
**************************************/
+#define LZ4_STATIC_LINKING_ONLY
+#define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */
#include "lz4.h"
/* see also "memory routines" below */
@@ -101,21 +106,43 @@
# pragma warning(disable : 4293) /* disable: C4293: too large shift (32-bits) */
#endif /* _MSC_VER */
-#ifndef FORCE_INLINE
+#ifndef LZ4_FORCE_INLINE
# ifdef _MSC_VER /* Visual Studio */
-# define FORCE_INLINE static __forceinline
+# define LZ4_FORCE_INLINE static __forceinline
# else
# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# ifdef __GNUC__
-# define FORCE_INLINE static inline __attribute__((always_inline))
+# define LZ4_FORCE_INLINE static inline __attribute__((always_inline))
# else
-# define FORCE_INLINE static inline
+# define LZ4_FORCE_INLINE static inline
# endif
# else
-# define FORCE_INLINE static
+# define LZ4_FORCE_INLINE static
# endif /* __STDC_VERSION__ */
# endif /* _MSC_VER */
-#endif /* FORCE_INLINE */
+#endif /* LZ4_FORCE_INLINE */
+
+/* LZ4_FORCE_O2_GCC_PPC64LE and LZ4_FORCE_O2_INLINE_GCC_PPC64LE
+ * Gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy,
+ * together with a simple 8-byte copy loop as a fall-back path.
+ * However, this optimization hurts the decompression speed by >30%,
+ * because the execution does not go to the optimized loop
+ * for typical compressible data, and all of the preamble checks
+ * before going to the fall-back path become useless overhead.
+ * This optimization happens only with the -O3 flag, and -O2 generates
+ * a simple 8-byte copy loop.
+ * With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy
+ * functions are annotated with __attribute__((optimize("O2"))),
+ * and also LZ4_wildCopy is forcibly inlined, so that the O2 attribute
+ * of LZ4_wildCopy does not affect the compression speed.
+ */
+#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__)
+# define LZ4_FORCE_O2_GCC_PPC64LE __attribute__((optimize("O2")))
+# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE __attribute__((optimize("O2"))) LZ4_FORCE_INLINE
+#else
+# define LZ4_FORCE_O2_GCC_PPC64LE
+# define LZ4_FORCE_O2_INLINE_GCC_PPC64LE static
+#endif
#if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__)
# define expect(expr,value) (__builtin_expect ((expr),(value)) )
@@ -123,18 +150,23 @@
# define expect(expr,value) (expr)
#endif
+#ifndef likely
#define likely(expr) expect((expr) != 0, 1)
+#endif
+#ifndef unlikely
#define unlikely(expr) expect((expr) != 0, 0)
+#endif
/*-************************************
* Memory routines
**************************************/
#include <stdlib.h> /* malloc, calloc, free */
-#define ALLOCATOR(n,s) calloc(n,s)
-#define FREEMEM free
+#define ALLOC(s) malloc(s)
+#define ALLOC_AND_ZERO(s) calloc(1,s)
+#define FREEMEM(p) free(p)
#include <string.h> /* memset, memcpy */
-#define MEM_INIT memset
+#define MEM_INIT(p,v,s) memset((p),(v),(s))
/*-************************************
@@ -247,19 +279,15 @@ static void LZ4_writeLE16(void* memPtr, U16 value)
}
}
-static void LZ4_copy8(void* dst, const void* src)
-{
- memcpy(dst,src,8);
-}
-
/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */
-static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
+LZ4_FORCE_O2_INLINE_GCC_PPC64LE
+void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
{
BYTE* d = (BYTE*)dstPtr;
const BYTE* s = (const BYTE*)srcPtr;
BYTE* const e = (BYTE*)dstEnd;
- do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
+ do { memcpy(d,s,8); d+=8; s+=8; } while (d<e);
}
@@ -269,8 +297,9 @@ static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
#define MINMATCH 4
#define WILDCOPYLENGTH 8
-#define LASTLITERALS 5
-#define MFLIMIT (WILDCOPYLENGTH+MINMATCH)
+#define LASTLITERALS 5 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
+#define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */
+#define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */
static const int LZ4_minLength = (MFLIMIT+1);
#define KB *(1 <<10)
@@ -289,15 +318,24 @@ static const int LZ4_minLength = (MFLIMIT+1);
/*-************************************
* Error detection
**************************************/
-#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
+# include <assert.h>
+#else
+# ifndef assert
+# define assert(condition) ((void)0)
+# endif
+#endif
+
+#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use after variable declarations */
#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
# include <stdio.h>
-# define DEBUGLOG(l, ...) { \
- if (l<=LZ4_DEBUG) { \
- fprintf(stderr, __FILE__ ": "); \
- fprintf(stderr, __VA_ARGS__); \
- fprintf(stderr, " \n"); \
+static int g_debuglog_enable = 1;
+# define DEBUGLOG(l, ...) { \
+ if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
+ fprintf(stderr, __FILE__ ": "); \
+ fprintf(stderr, __VA_ARGS__); \
+ fprintf(stderr, " \n"); \
} }
#else
# define DEBUGLOG(l, ...) {} /* disabled */
@@ -307,7 +345,7 @@ static const int LZ4_minLength = (MFLIMIT+1);
/*-************************************
* Common functions
**************************************/
-static unsigned LZ4_NbCommonBytes (register reg_t val)
+static unsigned LZ4_NbCommonBytes (reg_t val)
{
if (LZ4_isLittleEndian()) {
if (sizeof(val)==8) {
@@ -318,7 +356,14 @@ static unsigned LZ4_NbCommonBytes (register reg_t val)
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctzll((U64)val) >> 3);
# else
- static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
+ static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2,
+ 0, 3, 1, 3, 1, 4, 2, 7,
+ 0, 2, 3, 6, 1, 5, 3, 5,
+ 1, 3, 4, 4, 2, 5, 6, 7,
+ 7, 0, 1, 2, 3, 3, 4, 6,
+ 2, 6, 5, 5, 3, 4, 5, 6,
+ 7, 1, 2, 4, 6, 4, 4, 5,
+ 7, 2, 6, 5, 7, 6, 7, 7 };
return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
# endif
} else /* 32 bits */ {
@@ -329,12 +374,15 @@ static unsigned LZ4_NbCommonBytes (register reg_t val)
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_ctz((U32)val) >> 3);
# else
- static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
+ static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0,
+ 3, 2, 2, 1, 3, 2, 0, 1,
+ 3, 3, 1, 2, 2, 2, 2, 0,
+ 3, 1, 2, 0, 1, 0, 1, 1 };
return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
# endif
}
} else /* Big Endian CPU */ {
- if (sizeof(val)==8) {
+ if (sizeof(val)==8) { /* 64-bits */
# if defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT)
unsigned long r = 0;
_BitScanReverse64( &r, val );
@@ -342,8 +390,11 @@ static unsigned LZ4_NbCommonBytes (register reg_t val)
# elif (defined(__clang__) || (defined(__GNUC__) && (__GNUC__>=3))) && !defined(LZ4_FORCE_SW_BITCOUNT)
return (__builtin_clzll((U64)val) >> 3);
# else
+ static const U32 by32 = sizeof(val)*4; /* 32 on 64 bits (goal), 16 on 32 bits.
+ Just to avoid some static analyzer complaining about shift by 32 on 32-bits target.
+ Note that this code path is never triggered in 32-bits mode. */
unsigned r;
- if (!(val>>32)) { r=4; } else { r=0; val>>=32; }
+ if (!(val>>by32)) { r=4; } else { r=0; val>>=by32; }
if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
r += (!val);
return r;
@@ -366,11 +417,20 @@ static unsigned LZ4_NbCommonBytes (register reg_t val)
}
#define STEPSIZE sizeof(reg_t)
-static unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
+LZ4_FORCE_INLINE
+unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit)
{
const BYTE* const pStart = pIn;
- while (likely(pIn<pInLimit-(STEPSIZE-1))) {
+ if (likely(pIn < pInLimit-(STEPSIZE-1))) {
+ reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
+ if (!diff) {
+ pIn+=STEPSIZE; pMatch+=STEPSIZE;
+ } else {
+ return LZ4_NbCommonBytes(diff);
+ } }
+
+ while (likely(pIn < pInLimit-(STEPSIZE-1))) {
reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; }
pIn += LZ4_NbCommonBytes(diff);
@@ -395,15 +455,35 @@ static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression ru
/*-************************************
* Local Structures and types
**************************************/
-typedef enum { notLimited = 0, limitedOutput = 1 } limitedOutput_directive;
-typedef enum { byPtr, byU32, byU16 } tableType_t;
-
-typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
+typedef enum { notLimited = 0, limitedOutput = 1, fillOutput = 2 } limitedOutput_directive;
+typedef enum { clearedTable = 0, byPtr, byU32, byU16 } tableType_t;
+
+/**
+ * This enum distinguishes several different modes of accessing previous
+ * content in the stream.
+ *
+ * - noDict : There is no preceding content.
+ * - withPrefix64k : Table entries up to ctx->dictSize before the current blob
+ * blob being compressed are valid and refer to the preceding
+ * content (of length ctx->dictSize), which is available
+ * contiguously preceding in memory the content currently
+ * being compressed.
+ * - usingExtDict : Like withPrefix64k, but the preceding content is somewhere
+ * else in memory, starting at ctx->dictionary with length
+ * ctx->dictSize.
+ * - usingDictCtx : Like usingExtDict, but everything concerning the preceding
+ * content is in a separate context, pointed to by
+ * ctx->dictCtx. ctx->dictionary, ctx->dictSize, and table
+ * entries in the current context that refer to positions
+ * preceding the beginning of the current compression are
+ * ignored. Instead, ctx->dictCtx->dictionary and ctx->dictCtx
+ * ->dictSize describe the location and size of the preceding
+ * content, and matches are found by looking in the ctx
+ * ->dictCtx->hashTable.
+ */
+typedef enum { noDict = 0, withPrefix64k, usingExtDict, usingDictCtx } dict_directive;
typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
-typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
-typedef enum { full = 0, partial = 1 } earlyEnd_directive;
-
/*-************************************
* Local Utils
@@ -414,6 +494,21 @@ int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); }
int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
+/*-************************************
+* Internal Definitions used in Tests
+**************************************/
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize);
+
+int LZ4_decompress_safe_forceExtDict(const char* in, char* out, int inSize, int outSize, const void* dict, size_t dictSize);
+
+#if defined (__cplusplus)
+}
+#endif
+
/*-******************************
* Compression functions
********************************/
@@ -436,93 +531,190 @@ static U32 LZ4_hash5(U64 sequence, tableType_t const tableType)
return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
}
-FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType)
+LZ4_FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType)
{
if ((sizeof(reg_t)==8) && (tableType != byU16)) return LZ4_hash5(LZ4_read_ARCH(p), tableType);
return LZ4_hash4(LZ4_read32(p), tableType);
}
-static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
+static void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t const tableType)
+{
+ switch (tableType)
+ {
+ default: /* fallthrough */
+ case clearedTable: /* fallthrough */
+ case byPtr: { /* illegal! */ assert(0); return; }
+ case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = idx; return; }
+ case byU16: { U16* hashTable = (U16*) tableBase; assert(idx < 65536); hashTable[h] = (U16)idx; return; }
+ }
+}
+
+static void LZ4_putPositionOnHash(const BYTE* p, U32 h,
+ void* tableBase, tableType_t const tableType,
+ const BYTE* srcBase)
{
switch (tableType)
{
+ case clearedTable: { /* illegal! */ assert(0); return; }
case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = p; return; }
case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = (U32)(p-srcBase); return; }
case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = (U16)(p-srcBase); return; }
}
}
-FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+LZ4_FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
{
U32 const h = LZ4_hashPosition(p, tableType);
LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
}
-static const BYTE* LZ4_getPositionOnHash(U32 h, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+/* LZ4_getIndexOnHash() :
+ * Index of match position registered in hash table.
+ * hash position must be calculated by using base+index, or dictBase+index.
+ * Assumption 1 : only valid if tableType == byU32 or byU16.
+ * Assumption 2 : h is presumed valid (within limits of hash table)
+ */
+static U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType)
{
- if (tableType == byPtr) { const BYTE** hashTable = (const BYTE**) tableBase; return hashTable[h]; }
- if (tableType == byU32) { const U32* const hashTable = (U32*) tableBase; return hashTable[h] + srcBase; }
- { const U16* const hashTable = (U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
+ LZ4_STATIC_ASSERT(LZ4_MEMORY_USAGE > 2);
+ if (tableType == byU32) {
+ const U32* const hashTable = (const U32*) tableBase;
+ assert(h < (1U << (LZ4_MEMORY_USAGE-2)));
+ return hashTable[h];
+ }
+ if (tableType == byU16) {
+ const U16* const hashTable = (const U16*) tableBase;
+ assert(h < (1U << (LZ4_MEMORY_USAGE-1)));
+ return hashTable[h];
+ }
+ assert(0); return 0; /* forbidden case */
}
-FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p, void* tableBase, tableType_t tableType, const BYTE* srcBase)
+static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
+{
+ if (tableType == byPtr) { const BYTE* const* hashTable = (const BYTE* const*) tableBase; return hashTable[h]; }
+ if (tableType == byU32) { const U32* const hashTable = (const U32*) tableBase; return hashTable[h] + srcBase; }
+ { const U16* const hashTable = (const U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
+}
+
+LZ4_FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p,
+ const void* tableBase, tableType_t tableType,
+ const BYTE* srcBase)
{
U32 const h = LZ4_hashPosition(p, tableType);
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
}
+LZ4_FORCE_INLINE void LZ4_prepareTable(
+ LZ4_stream_t_internal* const cctx,
+ const int inputSize,
+ const tableType_t tableType) {
+ /* If the table hasn't been used, it's guaranteed to be zeroed out, and is
+ * therefore safe to use no matter what mode we're in. Otherwise, we figure
+ * out if it's safe to leave as is or whether it needs to be reset.
+ */
+ if (cctx->tableType != clearedTable) {
+ if (cctx->tableType != tableType
+ || (tableType == byU16 && cctx->currentOffset + inputSize >= 0xFFFFU)
+ || (tableType == byU32 && cctx->currentOffset > 1 GB)
+ || tableType == byPtr
+ || inputSize >= 4 KB)
+ {
+ DEBUGLOG(4, "LZ4_prepareTable: Resetting table in %p", cctx);
+ MEM_INIT(cctx->hashTable, 0, LZ4_HASHTABLESIZE);
+ cctx->currentOffset = 0;
+ cctx->tableType = clearedTable;
+ } else {
+ DEBUGLOG(4, "LZ4_prepareTable: Re-use hash table (no reset)");
+ }
+ }
+
+ /* Adding a gap, so all previous entries are > MAX_DISTANCE back, is faster
+ * than compressing without a gap. However, compressing with
+ * currentOffset == 0 is faster still, so we preserve that case.
+ */
+ if (cctx->currentOffset != 0 && tableType == byU32) {
+ DEBUGLOG(5, "LZ4_prepareTable: adding 64KB to currentOffset");
+ cctx->currentOffset += 64 KB;
+ }
+
+ /* Finally, clear history */
+ cctx->dictCtx = NULL;
+ cctx->dictionary = NULL;
+ cctx->dictSize = 0;
+}
/** LZ4_compress_generic() :
inlined, to ensure branches are decided at compilation time */
-FORCE_INLINE int LZ4_compress_generic(
+LZ4_FORCE_INLINE int LZ4_compress_generic(
LZ4_stream_t_internal* const cctx,
const char* const source,
char* const dest,
const int inputSize,
+ int *inputConsumed, /* only written when outputLimited == fillOutput */
const int maxOutputSize,
const limitedOutput_directive outputLimited,
const tableType_t tableType,
- const dict_directive dict,
+ const dict_directive dictDirective,
const dictIssue_directive dictIssue,
const U32 acceleration)
{
const BYTE* ip = (const BYTE*) source;
- const BYTE* base;
+
+ U32 const startIndex = cctx->currentOffset;
+ const BYTE* base = (const BYTE*) source - startIndex;
const BYTE* lowLimit;
- const BYTE* const lowRefLimit = ip - cctx->dictSize;
- const BYTE* const dictionary = cctx->dictionary;
- const BYTE* const dictEnd = dictionary + cctx->dictSize;
- const ptrdiff_t dictDelta = dictEnd - (const BYTE*)source;
+
+ const LZ4_stream_t_internal* dictCtx = (const LZ4_stream_t_internal*) cctx->dictCtx;
+ const BYTE* const dictionary =
+ dictDirective == usingDictCtx ? dictCtx->dictionary : cctx->dictionary;
+ const U32 dictSize =
+ dictDirective == usingDictCtx ? dictCtx->dictSize : cctx->dictSize;
+ const U32 dictDelta = (dictDirective == usingDictCtx) ? startIndex - dictCtx->currentOffset : 0; /* make indexes in dictCtx comparable with index in current context */
+
+ int const maybe_extMem = (dictDirective == usingExtDict) || (dictDirective == usingDictCtx);
+ U32 const prefixIdxLimit = startIndex - dictSize; /* used when dictDirective == dictSmall */
+ const BYTE* const dictEnd = dictionary + dictSize;
const BYTE* anchor = (const BYTE*) source;
const BYTE* const iend = ip + inputSize;
- const BYTE* const mflimit = iend - MFLIMIT;
+ const BYTE* const mflimitPlusOne = iend - MFLIMIT + 1;
const BYTE* const matchlimit = iend - LASTLITERALS;
+ /* the dictCtx currentOffset is indexed on the start of the dictionary,
+ * while a dictionary in the current context precedes the currentOffset */
+ const BYTE* dictBase = (dictDirective == usingDictCtx) ?
+ dictionary + dictSize - dictCtx->currentOffset :
+ dictionary + dictSize - startIndex;
+
BYTE* op = (BYTE*) dest;
BYTE* const olimit = op + maxOutputSize;
+ U32 offset = 0;
U32 forwardH;
+ DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, tableType=%u", inputSize, tableType);
/* Init conditions */
+ if (outputLimited == fillOutput && maxOutputSize < 1) return 0; /* Impossible to store anything */
if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported inputSize, too large (or negative) */
- switch(dict)
- {
- case noDict:
- default:
- base = (const BYTE*)source;
- lowLimit = (const BYTE*)source;
- break;
- case withPrefix64k:
- base = (const BYTE*)source - cctx->currentOffset;
- lowLimit = (const BYTE*)source - cctx->dictSize;
- break;
- case usingExtDict:
- base = (const BYTE*)source - cctx->currentOffset;
- lowLimit = (const BYTE*)source;
- break;
+ if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
+ if (tableType==byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */
+ assert(acceleration >= 1);
+
+ lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0);
+
+ /* Update context state */
+ if (dictDirective == usingDictCtx) {
+ /* Subsequent linked blocks can't use the dictionary. */
+ /* Instead, they use the block we just compressed. */
+ cctx->dictCtx = NULL;
+ cctx->dictSize = (U32)inputSize;
+ } else {
+ cctx->dictSize += (U32)inputSize;
}
- if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
- if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
+ cctx->currentOffset += (U32)inputSize;
+ cctx->tableType = (U16)tableType;
+
+ if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
/* First Byte */
LZ4_putPosition(ip, cctx->hashTable, tableType, base);
@@ -530,12 +722,12 @@ FORCE_INLINE int LZ4_compress_generic(
/* Main Loop */
for ( ; ; ) {
- ptrdiff_t refDelta = 0;
const BYTE* match;
BYTE* token;
/* Find a match */
- { const BYTE* forwardIp = ip;
+ if (tableType == byPtr) {
+ const BYTE* forwardIp = ip;
unsigned step = 1;
unsigned searchMatchNb = acceleration << LZ4_skipTrigger;
do {
@@ -544,34 +736,89 @@ FORCE_INLINE int LZ4_compress_generic(
forwardIp += step;
step = (searchMatchNb++ >> LZ4_skipTrigger);
- if (unlikely(forwardIp > mflimit)) goto _last_literals;
+ if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals;
+ assert(ip < mflimitPlusOne);
match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType, base);
- if (dict==usingExtDict) {
- if (match < (const BYTE*)source) {
- refDelta = dictDelta;
+ forwardH = LZ4_hashPosition(forwardIp, tableType);
+ LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base);
+
+ } while ( (match+MAX_DISTANCE < ip)
+ || (LZ4_read32(match) != LZ4_read32(ip)) );
+
+ } else { /* byU32, byU16 */
+
+ const BYTE* forwardIp = ip;
+ unsigned step = 1;
+ unsigned searchMatchNb = acceleration << LZ4_skipTrigger;
+ do {
+ U32 const h = forwardH;
+ U32 const current = (U32)(forwardIp - base);
+ U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
+ assert(matchIndex <= current);
+ assert(forwardIp - base < (ptrdiff_t)(2 GB - 1));
+ ip = forwardIp;
+ forwardIp += step;
+ step = (searchMatchNb++ >> LZ4_skipTrigger);
+
+ if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals;
+ assert(ip < mflimitPlusOne);
+
+ if (dictDirective == usingDictCtx) {
+ if (matchIndex < startIndex) {
+ /* there was no match, try the dictionary */
+ assert(tableType == byU32);
+ matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32);
+ match = dictBase + matchIndex;
+ matchIndex += dictDelta; /* make dictCtx index comparable with current context */
lowLimit = dictionary;
} else {
- refDelta = 0;
+ match = base + matchIndex;
lowLimit = (const BYTE*)source;
- } }
+ }
+ } else if (dictDirective==usingExtDict) {
+ if (matchIndex < startIndex) {
+ DEBUGLOG(7, "extDict candidate: matchIndex=%5u < startIndex=%5u", matchIndex, startIndex);
+ assert(startIndex - matchIndex >= MINMATCH);
+ match = dictBase + matchIndex;
+ lowLimit = dictionary;
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source;
+ }
+ } else { /* single continuous memory segment */
+ match = base + matchIndex;
+ }
forwardH = LZ4_hashPosition(forwardIp, tableType);
- LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType, base);
+ LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
+
+ if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) continue; /* match outside of valid area */
+ assert(matchIndex < current);
+ if ((tableType != byU16) && (matchIndex+MAX_DISTANCE < current)) continue; /* too far */
+ if (tableType == byU16) assert((current - matchIndex) <= MAX_DISTANCE); /* too_far presumed impossible with byU16 */
- } while ( ((dictIssue==dictSmall) ? (match < lowRefLimit) : 0)
- || ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
- || (LZ4_read32(match+refDelta) != LZ4_read32(ip)) );
+ if (LZ4_read32(match) == LZ4_read32(ip)) {
+ if (maybe_extMem) offset = current - matchIndex;
+ break; /* match found */
+ }
+
+ } while(1);
}
/* Catch up */
- while (((ip>anchor) & (match+refDelta > lowLimit)) && (unlikely(ip[-1]==match[refDelta-1]))) { ip--; match--; }
+ while (((ip>anchor) & (match > lowLimit)) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
/* Encode Literals */
{ unsigned const litLength = (unsigned)(ip - anchor);
token = op++;
- if ((outputLimited) && /* Check output buffer overflow */
+ if ((outputLimited == limitedOutput) && /* Check output buffer overflow */
(unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)))
return 0;
+ if ((outputLimited == fillOutput) &&
+ (unlikely(op + (litLength+240)/255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit))) {
+ op--;
+ goto _last_literals;
+ }
if (litLength >= RUN_MASK) {
int len = (int)litLength-RUN_MASK;
*token = (RUN_MASK<<ML_BITS);
@@ -583,40 +830,79 @@ FORCE_INLINE int LZ4_compress_generic(
/* Copy Literals */
LZ4_wildCopy(op, anchor, op+litLength);
op+=litLength;
+ DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
+ (int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source));
}
_next_match:
+ /* at this stage, the following variables must be correctly set :
+ * - ip : at start of LZ operation
+ * - match : at start of previous pattern occurence; can be within current prefix, or within extDict
+ * - offset : if maybe_ext_memSegment==1 (constant)
+ * - lowLimit : must be == dictionary to mean "match is within extDict"; must be == source otherwise
+ * - token and *token : position to write 4-bits for match length; higher 4-bits for literal length supposed already written
+ */
+
+ if ((outputLimited == fillOutput) &&
+ (op + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit)) {
+ /* the match was too close to the end, rewind and go to last literals */
+ op = token;
+ goto _last_literals;
+ }
+
/* Encode Offset */
- LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
+ if (maybe_extMem) { /* static test */
+ DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source));
+ assert(offset <= MAX_DISTANCE && offset > 0);
+ LZ4_writeLE16(op, (U16)offset); op+=2;
+ } else {
+ DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match));
+ assert(ip-match <= MAX_DISTANCE);
+ LZ4_writeLE16(op, (U16)(ip - match)); op+=2;
+ }
/* Encode MatchLength */
{ unsigned matchCode;
- if ((dict==usingExtDict) && (lowLimit==dictionary)) {
- const BYTE* limit;
- match += refDelta;
- limit = ip + (dictEnd-match);
+ if ( (dictDirective==usingExtDict || dictDirective==usingDictCtx)
+ && (lowLimit==dictionary) /* match within extDict */ ) {
+ const BYTE* limit = ip + (dictEnd-match);
+ assert(dictEnd > match);
if (limit > matchlimit) limit = matchlimit;
matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, limit);
ip += MINMATCH + matchCode;
if (ip==limit) {
- unsigned const more = LZ4_count(ip, (const BYTE*)source, matchlimit);
+ unsigned const more = LZ4_count(limit, (const BYTE*)source, matchlimit);
matchCode += more;
ip += more;
}
+ DEBUGLOG(6, " with matchLength=%u starting in extDict", matchCode+MINMATCH);
} else {
matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
ip += MINMATCH + matchCode;
+ DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH);
}
- if ( outputLimited && /* Check output buffer overflow */
- (unlikely(op + (1 + LASTLITERALS) + (matchCode>>8) > olimit)) )
- return 0;
+ if ((outputLimited) && /* Check output buffer overflow */
+ (unlikely(op + (1 + LASTLITERALS) + (matchCode>>8) > olimit)) ) {
+ if (outputLimited == limitedOutput)
+ return 0;
+ if (outputLimited == fillOutput) {
+ /* Match description too long : reduce it */
+ U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ((U32)(olimit - op) - 2 - 1 - LASTLITERALS) * 255;
+ ip -= matchCode - newMatchCode;
+ matchCode = newMatchCode;
+ }
+ }
if (matchCode >= ML_MASK) {
*token += ML_MASK;
matchCode -= ML_MASK;
LZ4_write32(op, 0xFFFFFFFF);
- while (matchCode >= 4*255) op+=4, LZ4_write32(op, 0xFFFFFFFF), matchCode -= 4*255;
+ while (matchCode >= 4*255) {
+ op+=4;
+ LZ4_write32(op, 0xFFFFFFFF);
+ matchCode -= 4*255;
+ }
op += matchCode / 255;
*op++ = (BYTE)(matchCode % 255);
} else
@@ -626,37 +912,80 @@ _next_match:
anchor = ip;
/* Test end of chunk */
- if (ip > mflimit) break;
+ if (ip >= mflimitPlusOne) break;
/* Fill table */
LZ4_putPosition(ip-2, cctx->hashTable, tableType, base);
/* Test next position */
- match = LZ4_getPosition(ip, cctx->hashTable, tableType, base);
- if (dict==usingExtDict) {
- if (match < (const BYTE*)source) {
- refDelta = dictDelta;
- lowLimit = dictionary;
- } else {
- refDelta = 0;
- lowLimit = (const BYTE*)source;
- } }
- LZ4_putPosition(ip, cctx->hashTable, tableType, base);
- if ( ((dictIssue==dictSmall) ? (match>=lowRefLimit) : 1)
- && (match+MAX_DISTANCE>=ip)
- && (LZ4_read32(match+refDelta)==LZ4_read32(ip)) )
- { token=op++; *token=0; goto _next_match; }
+ if (tableType == byPtr) {
+
+ match = LZ4_getPosition(ip, cctx->hashTable, tableType, base);
+ LZ4_putPosition(ip, cctx->hashTable, tableType, base);
+ if ( (match+MAX_DISTANCE >= ip)
+ && (LZ4_read32(match) == LZ4_read32(ip)) )
+ { token=op++; *token=0; goto _next_match; }
+
+ } else { /* byU32, byU16 */
+
+ U32 const h = LZ4_hashPosition(ip, tableType);
+ U32 const current = (U32)(ip-base);
+ U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType);
+ assert(matchIndex < current);
+ if (dictDirective == usingDictCtx) {
+ if (matchIndex < startIndex) {
+ /* there was no match, try the dictionary */
+ matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32);
+ match = dictBase + matchIndex;
+ lowLimit = dictionary; /* required for match length counter */
+ matchIndex += dictDelta;
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source; /* required for match length counter */
+ }
+ } else if (dictDirective==usingExtDict) {
+ if (matchIndex < startIndex) {
+ match = dictBase + matchIndex;
+ lowLimit = dictionary; /* required for match length counter */
+ } else {
+ match = base + matchIndex;
+ lowLimit = (const BYTE*)source; /* required for match length counter */
+ }
+ } else { /* single memory segment */
+ match = base + matchIndex;
+ }
+ LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType);
+ assert(matchIndex < current);
+ if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1)
+ && ((tableType==byU16) ? 1 : (matchIndex+MAX_DISTANCE >= current))
+ && (LZ4_read32(match) == LZ4_read32(ip)) ) {
+ token=op++;
+ *token=0;
+ if (maybe_extMem) offset = current - matchIndex;
+ DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
+ (int)(anchor-(const BYTE*)source), 0, (int)(ip-(const BYTE*)source));
+ goto _next_match;
+ }
+ }
/* Prepare next loop */
forwardH = LZ4_hashPosition(++ip, tableType);
+
}
_last_literals:
/* Encode Last Literals */
- { size_t const lastRun = (size_t)(iend - anchor);
+ { size_t lastRun = (size_t)(iend - anchor);
if ( (outputLimited) && /* Check output buffer overflow */
- ((op - (BYTE*)dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize) )
- return 0;
+ (op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > olimit)) {
+ if (outputLimited == fillOutput) {
+ /* adapt lastRun to fill 'dst' */
+ lastRun = (olimit-op) - 1;
+ lastRun -= (lastRun+240)/255;
+ }
+ if (outputLimited == limitedOutput)
+ return 0;
+ }
if (lastRun >= RUN_MASK) {
size_t accumulator = lastRun - RUN_MASK;
*op++ = RUN_MASK << ML_BITS;
@@ -666,44 +995,97 @@ _last_literals:
*op++ = (BYTE)(lastRun<<ML_BITS);
}
memcpy(op, anchor, lastRun);
+ ip = anchor + lastRun;
op += lastRun;
}
- /* End */
- return (int) (((char*)op)-dest);
+ if (outputLimited == fillOutput) {
+ *inputConsumed = (int) (((const char*)ip)-source);
+ }
+ DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, (int)(((char*)op) - dest));
+ return (int)(((char*)op) - dest);
}
int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
+ if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
LZ4_resetStream((LZ4_stream_t*)state);
+ if (maxOutputSize >= LZ4_compressBound(inputSize)) {
+ if (inputSize < LZ4_64Klimit) {
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32;
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ if (inputSize < LZ4_64Klimit) {;
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > MAX_DISTANCE)) ? byPtr : byU32;
+ return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
+ }
+}
+
+/**
+ * LZ4_compress_fast_extState_fastReset() :
+ * A variant of LZ4_compress_fast_extState().
+ *
+ * Using this variant avoids an expensive initialization step. It is only safe
+ * to call if the state buffer is known to be correctly initialized already
+ * (see comment in lz4.h on LZ4_resetStream_fast() for a definition of
+ * "correctly initialized").
+ */
+int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration)
+{
+ LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)state)->internal_donotuse;
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
- if (maxOutputSize >= LZ4_compressBound(inputSize)) {
- if (inputSize < LZ4_64Klimit)
- return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, byU16, noDict, noDictIssue, acceleration);
- else
- return LZ4_compress_generic(ctx, source, dest, inputSize, 0, notLimited, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue, acceleration);
+ if (dstCapacity >= LZ4_compressBound(srcSize)) {
+ if (srcSize < LZ4_64Klimit) {
+ const tableType_t tableType = byU16;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ if (ctx->currentOffset) {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, dictSmall, acceleration);
+ } else {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration);
+ }
} else {
- if (inputSize < LZ4_64Klimit)
- return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
- else
- return LZ4_compress_generic(ctx, source, dest, inputSize, maxOutputSize, limitedOutput, (sizeof(void*)==8) ? byU32 : byPtr, noDict, noDictIssue, acceleration);
+ if (srcSize < LZ4_64Klimit) {
+ const tableType_t tableType = byU16;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ if (ctx->currentOffset) {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, dictSmall, acceleration);
+ } else {
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
+ } else {
+ const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
+ LZ4_prepareTable(ctx, srcSize, tableType);
+ return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration);
+ }
}
}
int LZ4_compress_fast(const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
+ int result;
#if (LZ4_HEAPMODE)
- void* ctxPtr = ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ LZ4_stream_t* ctxPtr = ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ if (ctxPtr == NULL) return 0;
#else
LZ4_stream_t ctx;
- void* const ctxPtr = &ctx;
+ LZ4_stream_t* const ctxPtr = &ctx;
#endif
-
- int const result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
+ result = LZ4_compress_fast_extState(ctxPtr, source, dest, inputSize, maxOutputSize, acceleration);
#if (LZ4_HEAPMODE)
FREEMEM(ctxPtr);
@@ -726,172 +1108,15 @@ int LZ4_compress_fast_force(const char* source, char* dest, int inputSize, int m
LZ4_resetStream(&ctx);
if (inputSize < LZ4_64Klimit)
- return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
+ return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration);
else
- return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, maxOutputSize, limitedOutput, sizeof(void*)==8 ? byU32 : byPtr, noDict, noDictIssue, acceleration);
-}
-
-
-/*-******************************
-* *_destSize() variant
-********************************/
-
-static int LZ4_compress_destSize_generic(
- LZ4_stream_t_internal* const ctx,
- const char* const src,
- char* const dst,
- int* const srcSizePtr,
- const int targetDstSize,
- const tableType_t tableType)
-{
- const BYTE* ip = (const BYTE*) src;
- const BYTE* base = (const BYTE*) src;
- const BYTE* lowLimit = (const BYTE*) src;
- const BYTE* anchor = ip;
- const BYTE* const iend = ip + *srcSizePtr;
- const BYTE* const mflimit = iend - MFLIMIT;
- const BYTE* const matchlimit = iend - LASTLITERALS;
-
- BYTE* op = (BYTE*) dst;
- BYTE* const oend = op + targetDstSize;
- BYTE* const oMaxLit = op + targetDstSize - 2 /* offset */ - 8 /* because 8+MINMATCH==MFLIMIT */ - 1 /* token */;
- BYTE* const oMaxMatch = op + targetDstSize - (LASTLITERALS + 1 /* token */);
- BYTE* const oMaxSeq = oMaxLit - 1 /* token */;
-
- U32 forwardH;
-
-
- /* Init conditions */
- if (targetDstSize < 1) return 0; /* Impossible to store anything */
- if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
- if ((tableType == byU16) && (*srcSizePtr>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
- if (*srcSizePtr<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
-
- /* First Byte */
- *srcSizePtr = 0;
- LZ4_putPosition(ip, ctx->hashTable, tableType, base);
- ip++; forwardH = LZ4_hashPosition(ip, tableType);
-
- /* Main Loop */
- for ( ; ; ) {
- const BYTE* match;
- BYTE* token;
-
- /* Find a match */
- { const BYTE* forwardIp = ip;
- unsigned step = 1;
- unsigned searchMatchNb = 1 << LZ4_skipTrigger;
-
- do {
- U32 h = forwardH;
- ip = forwardIp;
- forwardIp += step;
- step = (searchMatchNb++ >> LZ4_skipTrigger);
-
- if (unlikely(forwardIp > mflimit)) goto _last_literals;
-
- match = LZ4_getPositionOnHash(h, ctx->hashTable, tableType, base);
- forwardH = LZ4_hashPosition(forwardIp, tableType);
- LZ4_putPositionOnHash(ip, h, ctx->hashTable, tableType, base);
-
- } while ( ((tableType==byU16) ? 0 : (match + MAX_DISTANCE < ip))
- || (LZ4_read32(match) != LZ4_read32(ip)) );
- }
-
- /* Catch up */
- while ((ip>anchor) && (match > lowLimit) && (unlikely(ip[-1]==match[-1]))) { ip--; match--; }
-
- /* Encode Literal length */
- { unsigned litLength = (unsigned)(ip - anchor);
- token = op++;
- if (op + ((litLength+240)/255) + litLength > oMaxLit) {
- /* Not enough space for a last match */
- op--;
- goto _last_literals;
- }
- if (litLength>=RUN_MASK) {
- unsigned len = litLength - RUN_MASK;
- *token=(RUN_MASK<<ML_BITS);
- for(; len >= 255 ; len-=255) *op++ = 255;
- *op++ = (BYTE)len;
- }
- else *token = (BYTE)(litLength<<ML_BITS);
-
- /* Copy Literals */
- LZ4_wildCopy(op, anchor, op+litLength);
- op += litLength;
- }
-
-_next_match:
- /* Encode Offset */
- LZ4_writeLE16(op, (U16)(ip-match)); op+=2;
-
- /* Encode MatchLength */
- { size_t matchLength = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit);
-
- if (op + ((matchLength+240)/255) > oMaxMatch) {
- /* Match description too long : reduce it */
- matchLength = (15-1) + (oMaxMatch-op) * 255;
- }
- ip += MINMATCH + matchLength;
-
- if (matchLength>=ML_MASK) {
- *token += ML_MASK;
- matchLength -= ML_MASK;
- while (matchLength >= 255) { matchLength-=255; *op++ = 255; }
- *op++ = (BYTE)matchLength;
- }
- else *token += (BYTE)(matchLength);
- }
-
- anchor = ip;
-
- /* Test end of block */
- if (ip > mflimit) break;
- if (op > oMaxSeq) break;
-
- /* Fill table */
- LZ4_putPosition(ip-2, ctx->hashTable, tableType, base);
-
- /* Test next position */
- match = LZ4_getPosition(ip, ctx->hashTable, tableType, base);
- LZ4_putPosition(ip, ctx->hashTable, tableType, base);
- if ( (match+MAX_DISTANCE>=ip)
- && (LZ4_read32(match)==LZ4_read32(ip)) )
- { token=op++; *token=0; goto _next_match; }
-
- /* Prepare next loop */
- forwardH = LZ4_hashPosition(++ip, tableType);
- }
-
-_last_literals:
- /* Encode Last Literals */
- { size_t lastRunSize = (size_t)(iend - anchor);
- if (op + 1 /* token */ + ((lastRunSize+240)/255) /* litLength */ + lastRunSize /* literals */ > oend) {
- /* adapt lastRunSize to fill 'dst' */
- lastRunSize = (oend-op) - 1;
- lastRunSize -= (lastRunSize+240)/255;
- }
- ip = anchor + lastRunSize;
-
- if (lastRunSize >= RUN_MASK) {
- size_t accumulator = lastRunSize - RUN_MASK;
- *op++ = RUN_MASK << ML_BITS;
- for(; accumulator >= 255 ; accumulator-=255) *op++ = 255;
- *op++ = (BYTE) accumulator;
- } else {
- *op++ = (BYTE)(lastRunSize<<ML_BITS);
- }
- memcpy(op, anchor, lastRunSize);
- op += lastRunSize;
- }
-
- /* End */
- *srcSizePtr = (int) (((const char*)ip)-src);
- return (int) (((char*)op)-dst);
+ return LZ4_compress_generic(&ctx.internal_donotuse, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, sizeof(void*)==8 ? byU32 : byPtr, noDict, noDictIssue, acceleration);
}
+/* Note!: This function leaves the stream in an unclean/broken state!
+ * It is not safe to subsequently use the same state with a _fastReset() or
+ * _continue() call without resetting it. */
static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize)
{
LZ4_resetStream(state);
@@ -899,18 +1124,20 @@ static int LZ4_compress_destSize_extState (LZ4_stream_t* state, const char* src,
if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) { /* compression success is guaranteed */
return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, 1);
} else {
- if (*srcSizePtr < LZ4_64Klimit)
- return LZ4_compress_destSize_generic(&state->internal_donotuse, src, dst, srcSizePtr, targetDstSize, byU16);
- else
- return LZ4_compress_destSize_generic(&state->internal_donotuse, src, dst, srcSizePtr, targetDstSize, sizeof(void*)==8 ? byU32 : byPtr);
- }
+ if (*srcSizePtr < LZ4_64Klimit) {
+ return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, byU16, noDict, noDictIssue, 1);
+ } else {
+ tableType_t const tableType = ((sizeof(void*)==4) && ((uptrval)src > MAX_DISTANCE)) ? byPtr : byU32;
+ return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, tableType, noDict, noDictIssue, 1);
+ } }
}
int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize)
{
#if (LZ4_HEAPMODE)
- LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOCATOR(1, sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ LZ4_stream_t* ctx = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */
+ if (ctx == NULL) return 0;
#else
LZ4_stream_t ctxBody;
LZ4_stream_t* ctx = &ctxBody;
@@ -932,20 +1159,28 @@ int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targe
LZ4_stream_t* LZ4_createStream(void)
{
- LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOCATOR(8, LZ4_STREAMSIZE_U64);
+ LZ4_stream_t* lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t));
LZ4_STATIC_ASSERT(LZ4_STREAMSIZE >= sizeof(LZ4_stream_t_internal)); /* A compilation error here means LZ4_STREAMSIZE is not large enough */
+ DEBUGLOG(4, "LZ4_createStream %p", lz4s);
+ if (lz4s == NULL) return NULL;
LZ4_resetStream(lz4s);
return lz4s;
}
void LZ4_resetStream (LZ4_stream_t* LZ4_stream)
{
+ DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream);
MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t));
}
+void LZ4_resetStream_fast(LZ4_stream_t* ctx) {
+ LZ4_prepareTable(&(ctx->internal_donotuse), 0, byU32);
+}
+
int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
{
if (!LZ4_stream) return 0; /* support free on NULL */
+ DEBUGLOG(5, "LZ4_freeStream %p", LZ4_stream);
FREEMEM(LZ4_stream);
return (0);
}
@@ -955,43 +1190,70 @@ int LZ4_freeStream (LZ4_stream_t* LZ4_stream)
int LZ4_loadDict (LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize)
{
LZ4_stream_t_internal* dict = &LZ4_dict->internal_donotuse;
+ const tableType_t tableType = byU32;
const BYTE* p = (const BYTE*)dictionary;
const BYTE* const dictEnd = p + dictSize;
const BYTE* base;
- if ((dict->initCheck) || (dict->currentOffset > 1 GB)) /* Uninitialized structure, or reuse overflow */
- LZ4_resetStream(LZ4_dict);
+ DEBUGLOG(4, "LZ4_loadDict (%i bytes from %p into %p)", dictSize, dictionary, LZ4_dict);
- if (dictSize < (int)HASH_UNIT) {
- dict->dictionary = NULL;
- dict->dictSize = 0;
- return 0;
- }
+ /* It's necessary to reset the context,
+ * and not just continue it with prepareTable()
+ * to avoid any risk of generating overflowing matchIndex
+ * when compressing using this dictionary */
+ LZ4_resetStream(LZ4_dict);
+
+ /* We always increment the offset by 64 KB, since, if the dict is longer,
+ * we truncate it to the last 64k, and if it's shorter, we still want to
+ * advance by a whole window length so we can provide the guarantee that
+ * there are only valid offsets in the window, which allows an optimization
+ * in LZ4_compress_fast_continue() where it uses noDictIssue even when the
+ * dictionary isn't a full 64k. */
if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB;
- dict->currentOffset += 64 KB;
- base = p - dict->currentOffset;
+ base = dictEnd - 64 KB - dict->currentOffset;
dict->dictionary = p;
dict->dictSize = (U32)(dictEnd - p);
- dict->currentOffset += dict->dictSize;
+ dict->currentOffset += 64 KB;
+ dict->tableType = tableType;
+
+ if (dictSize < (int)HASH_UNIT) {
+ return 0;
+ }
while (p <= dictEnd-HASH_UNIT) {
- LZ4_putPosition(p, dict->hashTable, byU32, base);
+ LZ4_putPosition(p, dict->hashTable, tableType, base);
p+=3;
}
return dict->dictSize;
}
+void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream) {
+ if (dictionary_stream != NULL) {
+ /* If the current offset is zero, we will never look in the
+ * external dictionary context, since there is no value a table
+ * entry can take that indicate a miss. In that case, we need
+ * to bump the offset to something non-zero.
+ */
+ if (working_stream->internal_donotuse.currentOffset == 0) {
+ working_stream->internal_donotuse.currentOffset = 64 KB;
+ }
+ working_stream->internal_donotuse.dictCtx = &(dictionary_stream->internal_donotuse);
+ } else {
+ working_stream->internal_donotuse.dictCtx = NULL;
+ }
+}
+
-static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
+static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize)
{
- if ((LZ4_dict->currentOffset > 0x80000000) ||
- ((uptrval)LZ4_dict->currentOffset > (uptrval)src)) { /* address space overflow */
+ if (LZ4_dict->currentOffset + nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */
/* rescale hash table */
U32 const delta = LZ4_dict->currentOffset - 64 KB;
const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
int i;
+ DEBUGLOG(4, "LZ4_renormDictT");
for (i=0; i<LZ4_HASH_SIZE_U32; i++) {
if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0;
else LZ4_dict->hashTable[i] -= delta;
@@ -1005,15 +1267,25 @@ static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, const BYTE* src)
int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration)
{
+ const tableType_t tableType = byU32;
LZ4_stream_t_internal* streamPtr = &LZ4_stream->internal_donotuse;
- const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
+ const BYTE* dictEnd = streamPtr->dictionary + streamPtr->dictSize;
+
+ DEBUGLOG(5, "LZ4_compress_fast_continue (inputSize=%i)", inputSize);
- const BYTE* smallest = (const BYTE*) source;
if (streamPtr->initCheck) return 0; /* Uninitialized structure detected */
- if ((streamPtr->dictSize>0) && (smallest>dictEnd)) smallest = dictEnd;
- LZ4_renormDictT(streamPtr, smallest);
+ LZ4_renormDictT(streamPtr, inputSize); /* avoid index overflow */
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
+ /* invalidate tiny dictionaries */
+ if ( (streamPtr->dictSize-1 < 4) /* intentional underflow */
+ && (dictEnd != (const BYTE*)source) ) {
+ DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary);
+ streamPtr->dictSize = 0;
+ streamPtr->dictionary = (const BYTE*)source;
+ dictEnd = (const BYTE*)source;
+ }
+
/* Check overlapping input/dictionary space */
{ const BYTE* sourceEnd = (const BYTE*) source + inputSize;
if ((sourceEnd > streamPtr->dictionary) && (sourceEnd < dictEnd)) {
@@ -1026,46 +1298,61 @@ int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, ch
/* prefix mode : source data follows dictionary */
if (dictEnd == (const BYTE*)source) {
- int result;
if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
- result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, withPrefix64k, dictSmall, acceleration);
+ return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, dictSmall, acceleration);
else
- result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, withPrefix64k, noDictIssue, acceleration);
- streamPtr->dictSize += (U32)inputSize;
- streamPtr->currentOffset += (U32)inputSize;
- return result;
+ return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, noDictIssue, acceleration);
}
/* external dictionary mode */
{ int result;
- if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset))
- result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, usingExtDict, dictSmall, acceleration);
- else
- result = LZ4_compress_generic(streamPtr, source, dest, inputSize, maxOutputSize, limitedOutput, byU32, usingExtDict, noDictIssue, acceleration);
+ if (streamPtr->dictCtx) {
+ /* We depend here on the fact that dictCtx'es (produced by
+ * LZ4_loadDict) guarantee that their tables contain no references
+ * to offsets between dictCtx->currentOffset - 64 KB and
+ * dictCtx->currentOffset - dictCtx->dictSize. This makes it safe
+ * to use noDictIssue even when the dict isn't a full 64 KB.
+ */
+ if (inputSize > 4 KB) {
+ /* For compressing large blobs, it is faster to pay the setup
+ * cost to copy the dictionary's tables into the active context,
+ * so that the compression loop is only looking into one table.
+ */
+ memcpy(streamPtr, streamPtr->dictCtx, sizeof(LZ4_stream_t));
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration);
+ }
+ } else {
+ if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration);
+ }
+ }
streamPtr->dictionary = (const BYTE*)source;
streamPtr->dictSize = (U32)inputSize;
- streamPtr->currentOffset += (U32)inputSize;
return result;
}
}
-/* Hidden debug function, to force external dictionary mode */
-int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int inputSize)
+/* Hidden debug function, to force-test external dictionary mode */
+int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize)
{
LZ4_stream_t_internal* streamPtr = &LZ4_dict->internal_donotuse;
int result;
- const BYTE* const dictEnd = streamPtr->dictionary + streamPtr->dictSize;
- const BYTE* smallest = dictEnd;
- if (smallest > (const BYTE*) source) smallest = (const BYTE*) source;
- LZ4_renormDictT(streamPtr, smallest);
+ LZ4_renormDictT(streamPtr, srcSize);
- result = LZ4_compress_generic(streamPtr, source, dest, inputSize, 0, notLimited, byU32, usingExtDict, noDictIssue, 1);
+ if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, dictSmall, 1);
+ } else {
+ result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, noDictIssue, 1);
+ }
streamPtr->dictionary = (const BYTE*)source;
- streamPtr->dictSize = (U32)inputSize;
- streamPtr->currentOffset += (U32)inputSize;
+ streamPtr->dictSize = (U32)srcSize;
return result;
}
@@ -1096,63 +1383,119 @@ int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize)
-/*-*****************************
-* Decompression functions
-*******************************/
+/*-*******************************
+ * Decompression functions
+ ********************************/
+
+typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
+typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
+
+#undef MIN
+#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
+
/*! LZ4_decompress_generic() :
- * This generic decompression function cover all use cases.
- * It shall be instantiated several times, using different sets of directives
- * Note that it is important this generic function is really inlined,
+ * This generic decompression function covers all use cases.
+ * It shall be instantiated several times, using different sets of directives.
+ * Note that it is important for performance that this function really get inlined,
* in order to remove useless branches during compilation optimization.
*/
-FORCE_INLINE int LZ4_decompress_generic(
- const char* const source,
- char* const dest,
- int inputSize,
- int outputSize, /* If endOnInput==endOnInputSize, this value is the max size of Output Buffer. */
-
- int endOnInput, /* endOnOutputSize, endOnInputSize */
- int partialDecoding, /* full, partial */
- int targetOutputSize, /* only used if partialDecoding==partial */
- int dict, /* noDict, withPrefix64k, usingExtDict */
- const BYTE* const lowPrefix, /* == dest when no prefix */
+LZ4_FORCE_INLINE int
+LZ4_decompress_generic(
+ const char* const src,
+ char* const dst,
+ int srcSize,
+ int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */
+
+ endCondition_directive endOnInput, /* endOnOutputSize, endOnInputSize */
+ earlyEnd_directive partialDecoding, /* full, partial */
+ dict_directive dict, /* noDict, withPrefix64k, usingExtDict */
+ const BYTE* const lowPrefix, /* always <= dst, == dst when no prefix */
const BYTE* const dictStart, /* only if dict==usingExtDict */
const size_t dictSize /* note : = 0 if noDict */
)
{
- /* Local Variables */
- const BYTE* ip = (const BYTE*) source;
- const BYTE* const iend = ip + inputSize;
+ const BYTE* ip = (const BYTE*) src;
+ const BYTE* const iend = ip + srcSize;
- BYTE* op = (BYTE*) dest;
+ BYTE* op = (BYTE*) dst;
BYTE* const oend = op + outputSize;
BYTE* cpy;
- BYTE* oexit = op + targetOutputSize;
- const BYTE* const lowLimit = lowPrefix - dictSize;
const BYTE* const dictEnd = (const BYTE*)dictStart + dictSize;
- const unsigned dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};
- const int dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
+ const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
+ const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};
const int safeDecode = (endOnInput==endOnInputSize);
const int checkOffset = ((safeDecode) && (dictSize < (int)(64 KB)));
+ /* Set up the "end" pointers for the shortcut. */
+ const BYTE* const shortiend = iend - (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
+ const BYTE* const shortoend = oend - (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
+
+ DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize);
/* Special cases */
- if ((partialDecoding) && (oexit > oend-MFLIMIT)) oexit = oend-MFLIMIT; /* targetOutputSize too high => decode everything */
- if ((endOnInput) && (unlikely(outputSize==0))) return ((inputSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */
- if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0?1:-1);
+ assert(lowPrefix <= op);
+ assert(src != NULL);
+ if ((endOnInput) && (unlikely(outputSize==0))) return ((srcSize==1) && (*ip==0)) ? 0 : -1; /* Empty output buffer */
+ if ((!endOnInput) && (unlikely(outputSize==0))) return (*ip==0 ? 1 : -1);
+ if ((endOnInput) && unlikely(srcSize==0)) return -1;
/* Main Loop : decode sequences */
while (1) {
- size_t length;
const BYTE* match;
size_t offset;
- /* get literal length */
unsigned const token = *ip++;
- if ((length=(token>>ML_BITS)) == RUN_MASK) {
+ size_t length = token >> ML_BITS; /* literal length */
+
+ assert(!endOnInput || ip <= iend); /* ip < iend before the increment */
+
+ /* A two-stage shortcut for the most common case:
+ * 1) If the literal length is 0..14, and there is enough space,
+ * enter the shortcut and copy 16 bytes on behalf of the literals
+ * (in the fast mode, only 8 bytes can be safely copied this way).
+ * 2) Further if the match length is 4..18, copy 18 bytes in a similar
+ * manner; but we ensure that there's enough space in the output for
+ * those 18 bytes earlier, upon entering the shortcut (in other words,
+ * there is a combined check for both stages).
+ */
+ if ( (endOnInput ? length != RUN_MASK : length <= 8)
+ /* strictly "less than" on input, to re-enter the loop with at least one byte */
+ && likely((endOnInput ? ip < shortiend : 1) & (op <= shortoend)) ) {
+ /* Copy the literals */
+ memcpy(op, ip, endOnInput ? 16 : 8);
+ op += length; ip += length;
+
+ /* The second stage: prepare for match copying, decode full info.
+ * If it doesn't work out, the info won't be wasted. */
+ length = token & ML_MASK; /* match length */
+ offset = LZ4_readLE16(ip); ip += 2;
+ match = op - offset;
+ assert(match <= op); /* check overflow */
+
+ /* Do not deal with overlapping matches. */
+ if ( (length != ML_MASK)
+ && (offset >= 8)
+ && (dict==withPrefix64k || match >= lowPrefix) ) {
+ /* Copy the match. */
+ memcpy(op + 0, match + 0, 8);
+ memcpy(op + 8, match + 8, 8);
+ memcpy(op +16, match +16, 2);
+ op += length + MINMATCH;
+ /* Both stages worked, load the next token. */
+ continue;
+ }
+
+ /* The second stage didn't work out, but the info is ready.
+ * Propel it right to the point of match copying. */
+ goto _copy_match;
+ }
+
+ /* decode literal length */
+ if (length == RUN_MASK) {
unsigned s;
+ if (unlikely(endOnInput ? ip >= iend-RUN_MASK : 0)) goto _output_error; /* overflow detection */
do {
s = *ip++;
length += s;
@@ -1163,11 +1506,12 @@ FORCE_INLINE int LZ4_decompress_generic(
/* copy literals */
cpy = op+length;
- if ( ((endOnInput) && ((cpy>(partialDecoding?oexit:oend-MFLIMIT)) || (ip+length>iend-(2+1+LASTLITERALS))) )
- || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) )
+ LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
+ if ( ((endOnInput) && ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) )
+ || ((!endOnInput) && (cpy>oend-WILDCOPYLENGTH)) )
{
if (partialDecoding) {
- if (cpy > oend) goto _output_error; /* Error : write attempt beyond end of output buffer */
+ if (cpy > oend) { cpy = oend; length = oend-op; } /* Partial decoding : stop in the middle of literal segment */
if ((endOnInput) && (ip+length > iend)) goto _output_error; /* Error : read attempt beyond end of input buffer */
} else {
if ((!endOnInput) && (cpy != oend)) goto _output_error; /* Error : block decoding must stop exactly there */
@@ -1176,19 +1520,31 @@ FORCE_INLINE int LZ4_decompress_generic(
memcpy(op, ip, length);
ip += length;
op += length;
- break; /* Necessarily EOF, due to parsing restrictions */
+ if (!partialDecoding || (cpy == oend)) {
+ /* Necessarily EOF, due to parsing restrictions */
+ break;
+ }
+
+ } else {
+ LZ4_wildCopy(op, ip, cpy); /* may overwrite up to WILDCOPYLENGTH beyond cpy */
+ ip += length; op = cpy;
}
- LZ4_wildCopy(op, ip, cpy);
- ip += length; op = cpy;
/* get offset */
offset = LZ4_readLE16(ip); ip+=2;
match = op - offset;
- if ((checkOffset) && (unlikely(match < lowLimit))) goto _output_error; /* Error : offset outside buffers */
- LZ4_write32(op, (U32)offset); /* costs ~1%; silence an msan warning when offset==0 */
/* get matchlength */
length = token & ML_MASK;
+
+_copy_match:
+ if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */
+ if (!partialDecoding) {
+ assert(oend > op);
+ assert(oend - op >= 4);
+ LZ4_write32(op, 0); /* silence an msan warning when offset==0; costs <1%; */
+ } /* note : when partialDecoding, there is no guarantee that at least 4 bytes remain available in output buffer */
+
if (length == ML_MASK) {
unsigned s;
do {
@@ -1200,21 +1556,24 @@ FORCE_INLINE int LZ4_decompress_generic(
}
length += MINMATCH;
- /* check external dictionary */
+ /* match starting within external dictionary */
if ((dict==usingExtDict) && (match < lowPrefix)) {
- if (unlikely(op+length > oend-LASTLITERALS)) goto _output_error; /* doesn't respect parsing restriction */
+ if (unlikely(op+length > oend-LASTLITERALS)) {
+ if (partialDecoding) length = MIN(length, (size_t)(oend-op));
+ else goto _output_error; /* doesn't respect parsing restriction */
+ }
if (length <= (size_t)(lowPrefix-match)) {
- /* match can be copied as a single segment from external dictionary */
+ /* match fits entirely within external dictionary : just copy */
memmove(op, dictEnd - (lowPrefix-match), length);
op += length;
} else {
- /* match encompass external dictionary and current block */
- size_t const copySize = (size_t)(lowPrefix-match);
+ /* match stretches into both external dictionary and current block */
+ size_t const copySize = (size_t)(lowPrefix - match);
size_t const restSize = length - copySize;
memcpy(op, dictEnd - copySize, copySize);
op += copySize;
- if (restSize > (size_t)(op-lowPrefix)) { /* overlap copy */
+ if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */
BYTE* const endOfMatch = op + restSize;
const BYTE* copyFrom = lowPrefix;
while (op < endOfMatch) *op++ = *copyFrom++;
@@ -1227,67 +1586,165 @@ FORCE_INLINE int LZ4_decompress_generic(
/* copy match within block */
cpy = op + length;
+
+ /* partialDecoding : may not respect endBlock parsing restrictions */
+ assert(op<=oend);
+ if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
+ size_t const mlen = MIN(length, (size_t)(oend-op));
+ const BYTE* const matchEnd = match + mlen;
+ BYTE* const copyEnd = op + mlen;
+ if (matchEnd > op) { /* overlap copy */
+ while (op < copyEnd) *op++ = *match++;
+ } else {
+ memcpy(op, match, mlen);
+ }
+ op = copyEnd;
+ if (op==oend) break;
+ continue;
+ }
+
if (unlikely(offset<8)) {
- const int dec64 = dec64table[offset];
op[0] = match[0];
op[1] = match[1];
op[2] = match[2];
op[3] = match[3];
- match += dec32table[offset];
+ match += inc32table[offset];
memcpy(op+4, match, 4);
- match -= dec64;
- } else { LZ4_copy8(op, match); match+=8; }
+ match -= dec64table[offset];
+ } else {
+ memcpy(op, match, 8);
+ match += 8;
+ }
op += 8;
- if (unlikely(cpy>oend-12)) {
- BYTE* const oCopyLimit = oend-(WILDCOPYLENGTH-1);
+ if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) {
+ BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1);
if (cpy > oend-LASTLITERALS) goto _output_error; /* Error : last LASTLITERALS bytes must be literals (uncompressed) */
if (op < oCopyLimit) {
LZ4_wildCopy(op, match, oCopyLimit);
match += oCopyLimit - op;
op = oCopyLimit;
}
- while (op<cpy) *op++ = *match++;
+ while (op < cpy) *op++ = *match++;
} else {
- LZ4_copy8(op, match);
- if (length>16) LZ4_wildCopy(op+8, match+8, cpy);
+ memcpy(op, match, 8);
+ if (length > 16) LZ4_wildCopy(op+8, match+8, cpy);
}
- op=cpy; /* correction */
+ op = cpy; /* wildcopy correction */
}
/* end of decoding */
if (endOnInput)
- return (int) (((char*)op)-dest); /* Nb of output bytes decoded */
+ return (int) (((char*)op)-dst); /* Nb of output bytes decoded */
else
- return (int) (((const char*)ip)-source); /* Nb of input bytes read */
+ return (int) (((const char*)ip)-src); /* Nb of input bytes read */
/* Overflow error detected */
_output_error:
- return (int) (-(((const char*)ip)-source))-1;
+ return (int) (-(((const char*)ip)-src))-1;
}
+/*===== Instantiate the API decoding functions. =====*/
+
+LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
{
- return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, full, 0, noDict, (BYTE*)dest, NULL, 0);
+ return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
+ endOnInputSize, decode_full_block, noDict,
+ (BYTE*)dest, NULL, 0);
}
-int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize)
+LZ4_FORCE_O2_GCC_PPC64LE
+int LZ4_decompress_safe_partial(const char* src, char* dst, int compressedSize, int targetOutputSize, int dstCapacity)
{
- return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, partial, targetOutputSize, noDict, (BYTE*)dest, NULL, 0);
+ dstCapacity = MIN(targetOutputSize, dstCapacity);
+ return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
+ endOnInputSize, partial_decode,
+ noDict, (BYTE*)dst, NULL, 0);
}
+LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_fast(const char* source, char* dest, int originalSize)
{
- return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, (BYTE*)(dest - 64 KB), NULL, 64 KB);
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, withPrefix64k,
+ (BYTE*)dest - 64 KB, NULL, 0);
+}
+
+/*===== Instantiate a few more decoding cases, used more than once. =====*/
+
+LZ4_FORCE_O2_GCC_PPC64LE /* Exported, an obsolete API function. */
+int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, withPrefix64k,
+ (BYTE*)dest - 64 KB, NULL, 0);
+}
+
+/* Another obsolete API function, paired with the previous one. */
+int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
+{
+ /* LZ4_decompress_fast doesn't validate match offsets,
+ * and thus serves well with any prefixed dictionary. */
+ return LZ4_decompress_fast(source, dest, originalSize);
+}
+
+LZ4_FORCE_O2_GCC_PPC64LE
+static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize,
+ size_t prefixSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, noDict,
+ (BYTE*)dest-prefixSize, NULL, 0);
+}
+
+LZ4_FORCE_O2_GCC_PPC64LE
+int LZ4_decompress_safe_forceExtDict(const char* source, char* dest,
+ int compressedSize, int maxOutputSize,
+ const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest, (const BYTE*)dictStart, dictSize);
+}
+
+LZ4_FORCE_O2_GCC_PPC64LE
+static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize,
+ const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest, (const BYTE*)dictStart, dictSize);
}
+/* The "double dictionary" mode, for use with e.g. ring buffers: the first part
+ * of the dictionary is passed as prefix, and the second via dictStart + dictSize.
+ * These routines are used only once, in LZ4_decompress_*_continue().
+ */
+LZ4_FORCE_INLINE
+int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compressedSize, int maxOutputSize,
+ size_t prefixSize, const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
+ endOnInputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
+}
+
+LZ4_FORCE_INLINE
+int LZ4_decompress_fast_doubleDict(const char* source, char* dest, int originalSize,
+ size_t prefixSize, const void* dictStart, size_t dictSize)
+{
+ return LZ4_decompress_generic(source, dest, 0, originalSize,
+ endOnOutputSize, decode_full_block, usingExtDict,
+ (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize);
+}
/*===== streaming decompression functions =====*/
LZ4_streamDecode_t* LZ4_createStreamDecode(void)
{
- LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOCATOR(1, sizeof(LZ4_streamDecode_t));
+ LZ4_streamDecode_t* lz4s = (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t));
return lz4s;
}
@@ -1298,12 +1755,11 @@ int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream)
return 0;
}
-/*!
- * LZ4_setStreamDecode() :
- * Use this function to instruct where to find the dictionary.
- * This function is not necessary if previous data is still available where it was decoded.
- * Loading a size of 0 is allowed (same effect as no dictionary).
- * Return : 1 if OK, 0 if error
+/*! LZ4_setStreamDecode() :
+ * Use this function to instruct where to find the dictionary.
+ * This function is not necessary if previous data is still available where it was decoded.
+ * Loading a size of 0 is allowed (same effect as no dictionary).
+ * @return : 1 if OK, 0 if error
*/
int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize)
{
@@ -1315,6 +1771,25 @@ int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dicti
return 1;
}
+/*! LZ4_decoderRingBufferSize() :
+ * when setting a ring buffer for streaming decompression (optional scenario),
+ * provides the minimum size of this ring buffer
+ * to be compatible with any source respecting maxBlockSize condition.
+ * Note : in a ring buffer scenario,
+ * blocks are presumed decompressed next to each other.
+ * When not enough space remains for next block (remainingSize < maxBlockSize),
+ * decoding resumes from beginning of ring buffer.
+ * @return : minimum ring buffer size,
+ * or 0 if there is an error (invalid maxBlockSize).
+ */
+int LZ4_decoderRingBufferSize(int maxBlockSize)
+{
+ if (maxBlockSize < 0) return 0;
+ if (maxBlockSize > LZ4_MAX_INPUT_SIZE) return 0;
+ if (maxBlockSize < 16) maxBlockSize = 16;
+ return LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize);
+}
+
/*
*_continue() :
These decoding functions allow decompression of multiple blocks in "streaming" mode.
@@ -1322,24 +1797,38 @@ int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dicti
If it's not possible, save the relevant part of decoded data into a safe buffer,
and indicate where it stands using LZ4_setStreamDecode()
*/
+LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize)
{
LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
int result;
- if (lz4sd->prefixEnd == (BYTE*)dest) {
- result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
- endOnInputSize, full, 0,
- usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
+ if (lz4sd->prefixSize == 0) {
+ /* The first call, no dictionary yet. */
+ assert(lz4sd->extDictSize == 0);
+ result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = result;
+ lz4sd->prefixEnd = (BYTE*)dest + result;
+ } else if (lz4sd->prefixEnd == (BYTE*)dest) {
+ /* They're rolling the current segment. */
+ if (lz4sd->prefixSize >= 64 KB - 1)
+ result = LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
+ else if (lz4sd->extDictSize == 0)
+ result = LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize,
+ lz4sd->prefixSize);
+ else
+ result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize,
+ lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
if (result <= 0) return result;
lz4sd->prefixSize += result;
lz4sd->prefixEnd += result;
} else {
+ /* The buffer wraps around, or they're switching to another buffer. */
lz4sd->extDictSize = lz4sd->prefixSize;
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
- result = LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize,
- endOnInputSize, full, 0,
- usingExtDict, (BYTE*)dest, lz4sd->externalDict, lz4sd->extDictSize);
+ result = LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize,
+ lz4sd->externalDict, lz4sd->extDictSize);
if (result <= 0) return result;
lz4sd->prefixSize = result;
lz4sd->prefixEnd = (BYTE*)dest + result;
@@ -1348,24 +1837,32 @@ int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch
return result;
}
+LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize)
{
LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse;
int result;
- if (lz4sd->prefixEnd == (BYTE*)dest) {
- result = LZ4_decompress_generic(source, dest, 0, originalSize,
- endOnOutputSize, full, 0,
- usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
+ if (lz4sd->prefixSize == 0) {
+ assert(lz4sd->extDictSize == 0);
+ result = LZ4_decompress_fast(source, dest, originalSize);
+ if (result <= 0) return result;
+ lz4sd->prefixSize = originalSize;
+ lz4sd->prefixEnd = (BYTE*)dest + originalSize;
+ } else if (lz4sd->prefixEnd == (BYTE*)dest) {
+ if (lz4sd->prefixSize >= 64 KB - 1 || lz4sd->extDictSize == 0)
+ result = LZ4_decompress_fast(source, dest, originalSize);
+ else
+ result = LZ4_decompress_fast_doubleDict(source, dest, originalSize,
+ lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize);
if (result <= 0) return result;
lz4sd->prefixSize += originalSize;
lz4sd->prefixEnd += originalSize;
} else {
lz4sd->extDictSize = lz4sd->prefixSize;
lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
- result = LZ4_decompress_generic(source, dest, 0, originalSize,
- endOnOutputSize, full, 0,
- usingExtDict, (BYTE*)dest, lz4sd->externalDict, lz4sd->extDictSize);
+ result = LZ4_decompress_fast_extDict(source, dest, originalSize,
+ lz4sd->externalDict, lz4sd->extDictSize);
if (result <= 0) return result;
lz4sd->prefixSize = originalSize;
lz4sd->prefixEnd = (BYTE*)dest + originalSize;
@@ -1382,32 +1879,23 @@ Advanced decoding functions :
the dictionary must be explicitly provided within parameters
*/
-FORCE_INLINE int LZ4_decompress_usingDict_generic(const char* source, char* dest, int compressedSize, int maxOutputSize, int safe, const char* dictStart, int dictSize)
+int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
{
if (dictSize==0)
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, (BYTE*)dest, NULL, 0);
+ return LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize);
if (dictStart+dictSize == dest) {
- if (dictSize >= (int)(64 KB - 1))
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, withPrefix64k, (BYTE*)dest-64 KB, NULL, 0);
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, noDict, (BYTE*)dest-dictSize, NULL, 0);
+ if (dictSize >= 64 KB - 1)
+ return LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize);
+ return LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, dictSize);
}
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, safe, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize);
-}
-
-int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
-{
- return LZ4_decompress_usingDict_generic(source, dest, compressedSize, maxOutputSize, 1, dictStart, dictSize);
+ return LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, dictStart, dictSize);
}
int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize)
{
- return LZ4_decompress_usingDict_generic(source, dest, 0, originalSize, 0, dictStart, dictSize);
-}
-
-/* debug function */
-int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize)
-{
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, usingExtDict, (BYTE*)dest, (const BYTE*)dictStart, dictSize);
+ if (dictSize==0 || dictStart+dictSize == dest)
+ return LZ4_decompress_fast(source, dest, originalSize);
+ return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, dictSize);
}
@@ -1415,64 +1903,67 @@ int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compres
* Obsolete Functions
***************************************************/
/* obsolete compression functions */
-int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize) { return LZ4_compress_default(source, dest, inputSize, maxOutputSize); }
-int LZ4_compress(const char* source, char* dest, int inputSize) { return LZ4_compress_default(source, dest, inputSize, LZ4_compressBound(inputSize)); }
-int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize) { return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1); }
-int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize) { return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1); }
-int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, maxDstSize, 1); }
-int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize) { return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1); }
+int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
+{
+ return LZ4_compress_default(source, dest, inputSize, maxOutputSize);
+}
+int LZ4_compress(const char* source, char* dest, int inputSize)
+{
+ return LZ4_compress_default(source, dest, inputSize, LZ4_compressBound(inputSize));
+}
+int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize)
+{
+ return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1);
+}
+int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize)
+{
+ return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1);
+}
+int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int dstCapacity)
+{
+ return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, dstCapacity, 1);
+}
+int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize)
+{
+ return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1);
+}
/*
-These function names are deprecated and should no longer be used.
+These decompression functions are deprecated and should no longer be used.
They are only provided here for compatibility with older user programs.
- LZ4_uncompress is totally equivalent to LZ4_decompress_fast
- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
*/
-int LZ4_uncompress (const char* source, char* dest, int outputSize) { return LZ4_decompress_fast(source, dest, outputSize); }
-int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) { return LZ4_decompress_safe(source, dest, isize, maxOutputSize); }
-
+int LZ4_uncompress (const char* source, char* dest, int outputSize)
+{
+ return LZ4_decompress_fast(source, dest, outputSize);
+}
+int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize)
+{
+ return LZ4_decompress_safe(source, dest, isize, maxOutputSize);
+}
/* Obsolete Streaming functions */
int LZ4_sizeofStreamState() { return LZ4_STREAMSIZE; }
-static void LZ4_init(LZ4_stream_t* lz4ds, BYTE* base)
-{
- MEM_INIT(lz4ds, 0, sizeof(LZ4_stream_t));
- lz4ds->internal_donotuse.bufferStart = base;
-}
-
int LZ4_resetStreamState(void* state, char* inputBuffer)
{
- if ((((uptrval)state) & 3) != 0) return 1; /* Error : pointer is not aligned on 4-bytes boundary */
- LZ4_init((LZ4_stream_t*)state, (BYTE*)inputBuffer);
+ (void)inputBuffer;
+ LZ4_resetStream((LZ4_stream_t*)state);
return 0;
}
void* LZ4_create (char* inputBuffer)
{
- LZ4_stream_t* lz4ds = (LZ4_stream_t*)ALLOCATOR(8, sizeof(LZ4_stream_t));
- LZ4_init (lz4ds, (BYTE*)inputBuffer);
- return lz4ds;
-}
-
-char* LZ4_slideInputBuffer (void* LZ4_Data)
-{
- LZ4_stream_t_internal* ctx = &((LZ4_stream_t*)LZ4_Data)->internal_donotuse;
- int dictSize = LZ4_saveDict((LZ4_stream_t*)LZ4_Data, (char*)ctx->bufferStart, 64 KB);
- return (char*)(ctx->bufferStart + dictSize);
+ (void)inputBuffer;
+ return LZ4_createStream();
}
-/* Obsolete streaming decompression functions */
-
-int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize)
-{
- return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, endOnInputSize, full, 0, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 64 KB);
-}
-
-int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize)
+char* LZ4_slideInputBuffer (void* state)
{
- return LZ4_decompress_generic(source, dest, 0, originalSize, endOnOutputSize, full, 0, withPrefix64k, (BYTE*)dest - 64 KB, NULL, 64 KB);
+ /* avoid const char * -> char * conversion warning */
+ return (char *)(uptrval)((LZ4_stream_t*)state)->internal_donotuse.dictionary;
}
#endif /* LZ4_COMMONDEFS_ONLY */
diff --git a/lib/lz4.h b/lib/lz4.h
index 5b09dd237ae..af9a7330d4f 100644
--- a/lib/lz4.h
+++ b/lib/lz4.h
@@ -1,7 +1,7 @@
/*
* LZ4 - Fast LZ compression algorithm
* Header File
- * Copyright (C) 2011-2017, Yann Collet.
+ * Copyright (C) 2011-present, Yann Collet.
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
@@ -48,7 +48,7 @@ extern "C" {
/**
Introduction
- LZ4 is lossless compression algorithm, providing compression speed at 400 MB/s per core,
+ LZ4 is lossless compression algorithm, providing compression speed at 500 MB/s per core,
scalable with multi-cores CPU. It features an extremely fast decoder, with speed in
multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.
@@ -64,8 +64,8 @@ extern "C" {
An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md),
take care of encoding standard metadata alongside LZ4-compressed blocks.
- If your application requires interoperability, it's recommended to use it.
- A library is provided to take care of it, see lz4frame.h.
+ Frame format is required for interoperability.
+ It is delivered through a companion API, declared in lz4frame.h.
*/
/*^***************************************************************
@@ -74,24 +74,28 @@ extern "C" {
/*
* LZ4_DLL_EXPORT :
* Enable exporting of functions when building a Windows DLL
-* LZ4LIB_API :
+* LZ4LIB_VISIBILITY :
* Control library symbols visibility.
*/
+#ifndef LZ4LIB_VISIBILITY
+# if defined(__GNUC__) && (__GNUC__ >= 4)
+# define LZ4LIB_VISIBILITY __attribute__ ((visibility ("default")))
+# else
+# define LZ4LIB_VISIBILITY
+# endif
+#endif
#if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
-# define LZ4LIB_API __declspec(dllexport)
+# define LZ4LIB_API __declspec(dllexport) LZ4LIB_VISIBILITY
#elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
-# define LZ4LIB_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
-#elif defined(__GNUC__) && (__GNUC__ >= 4)
-# define LZ4LIB_API __attribute__ ((__visibility__ ("default")))
+# define LZ4LIB_API __declspec(dllimport) LZ4LIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
#else
-# define LZ4LIB_API
+# define LZ4LIB_API LZ4LIB_VISIBILITY
#endif
-
/*------ Version ------*/
#define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
#define LZ4_VERSION_MINOR 8 /* for new (non-breaking) interface capabilities */
-#define LZ4_VERSION_RELEASE 0 /* for tweaks, bug-fixes, or development */
+#define LZ4_VERSION_RELEASE 3 /* for tweaks, bug-fixes, or development */
#define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
@@ -100,8 +104,8 @@ extern "C" {
#define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
#define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
-LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; to be used when checking dll version */
-LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; to be used when checking dll version */
+LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version */
+LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; unseful to check dll version */
/*-************************************
@@ -111,7 +115,7 @@ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string;
* LZ4_MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
* Increasing memory usage improves compression ratio
- * Reduced memory usage can improve speed, due to cache effect
+ * Reduced memory usage may improve speed, thanks to cache effect
* Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
*/
#ifndef LZ4_MEMORY_USAGE
@@ -122,30 +126,29 @@ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string;
* Simple Functions
**************************************/
/*! LZ4_compress_default() :
- Compresses 'sourceSize' bytes from buffer 'source'
- into already allocated 'dest' buffer of size 'maxDestSize'.
- Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
+ Compresses 'srcSize' bytes from buffer 'src'
+ into already allocated 'dst' buffer of size 'dstCapacity'.
+ Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize).
It also runs faster, so it's a recommended setting.
- If the function cannot compress 'source' into a more limited 'dest' budget,
+ If the function cannot compress 'src' into a more limited 'dst' budget,
compression stops *immediately*, and the function result is zero.
- As a consequence, 'dest' content is not valid.
- This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
- sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE
- maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
- return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
- or 0 if compression fails */
-LZ4LIB_API int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
+ Note : as a consequence, 'dst' content is not valid.
+ Note 2 : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer).
+ srcSize : max supported value is LZ4_MAX_INPUT_SIZE.
+ dstCapacity : size of buffer 'dst' (which must be already allocated)
+ return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity)
+ or 0 if compression fails */
+LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity);
/*! LZ4_decompress_safe() :
- compressedSize : is the precise full size of the compressed block.
- maxDecompressedSize : is the size of destination buffer, which must be already allocated.
- return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
- If destination buffer is not large enough, decoding will stop and output an error code (<0).
+ compressedSize : is the exact complete size of the compressed block.
+ dstCapacity : is the size of destination buffer, which must be already allocated.
+ return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity)
+ If destination buffer is not large enough, decoding will stop and output an error code (negative value).
If the source stream is detected malformed, the function will stop decoding and return a negative result.
- This function is protected against buffer overflow exploits, including malicious data packets.
- It never writes outside output buffer, nor reads outside input buffer.
+ This function is protected against malicious data packets.
*/
-LZ4LIB_API int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
+LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity);
/*-************************************
@@ -159,22 +162,22 @@ LZ4_compressBound() :
Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
This function is primarily useful for memory allocation purposes (destination buffer size).
Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
- Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
+ Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize)
inputSize : max supported value is LZ4_MAX_INPUT_SIZE
return : maximum output size in a "worst case" scenario
- or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
+ or 0, if input size is incorrect (too large or negative)
*/
LZ4LIB_API int LZ4_compressBound(int inputSize);
/*!
LZ4_compress_fast() :
- Same as LZ4_compress_default(), but allows to select an "acceleration" factor.
+ Same as LZ4_compress_default(), but allows selection of "acceleration" factor.
The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
An acceleration value of "1" is the same as regular LZ4_compress_default()
- Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
+ Values <= 0 will be replaced by ACCELERATION_DEFAULT (currently == 1, see lz4.c).
*/
-LZ4LIB_API int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
+LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
/*!
@@ -182,58 +185,79 @@ LZ4_compress_fast_extState() :
Same compression function, just using an externally allocated memory space to store compression state.
Use LZ4_sizeofState() to know how much memory must be allocated,
and allocate it on 8-bytes boundaries (using malloc() typically).
- Then, provide it as 'void* state' to compression function.
+ Then, provide this buffer as 'void* state' to compression function.
*/
LZ4LIB_API int LZ4_sizeofState(void);
-LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
-
-
-/*!
-LZ4_compress_destSize() :
- Reverse the logic, by compressing as much data as possible from 'source' buffer
- into already allocated buffer 'dest' of size 'targetDestSize'.
- This function either compresses the entire 'source' content into 'dest' if it's large enough,
- or fill 'dest' buffer completely with as much data as possible from 'source'.
- *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
- New value is necessarily <= old value.
- return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
- or 0 if compression fails
+LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
+
+
+/*! LZ4_compress_destSize() :
+ * Reverse the logic : compresses as much data as possible from 'src' buffer
+ * into already allocated buffer 'dst', of size >= 'targetDestSize'.
+ * This function either compresses the entire 'src' content into 'dst' if it's large enough,
+ * or fill 'dst' buffer completely with as much data as possible from 'src'.
+ * note: acceleration parameter is fixed to "default".
+ *
+ * *srcSizePtr : will be modified to indicate how many bytes where read from 'src' to fill 'dst'.
+ * New value is necessarily <= input value.
+ * @return : Nb bytes written into 'dst' (necessarily <= targetDestSize)
+ * or 0 if compression fails.
*/
-LZ4LIB_API int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
-
-
-/*!
-LZ4_decompress_fast() :
- originalSize : is the original and therefore uncompressed size
- return : the number of bytes read from the source buffer (in other words, the compressed size)
- If the source stream is detected malformed, the function will stop decoding and return a negative result.
- Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
- note : This function fully respect memory boundaries for properly formed compressed data.
- It is a bit faster than LZ4_decompress_safe().
- However, it does not provide any protection against intentionally modified data stream (malicious input).
- Use this function in trusted environment only (data to decode comes from a trusted source).
-*/
-LZ4LIB_API int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
-
-/*!
-LZ4_decompress_safe_partial() :
- This function decompress a compressed block of size 'compressedSize' at position 'source'
- into destination buffer 'dest' of size 'maxDecompressedSize'.
- The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
- reducing decompression time.
- return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
- Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
- Always control how many bytes were decoded.
- If the source stream is detected malformed, the function will stop decoding and return a negative result.
- This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
-*/
-LZ4LIB_API int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
+LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize);
+
+
+/*! LZ4_decompress_fast() : **unsafe!**
+ * This function used to be a bit faster than LZ4_decompress_safe(),
+ * though situation has changed in recent versions,
+ * and now `LZ4_decompress_safe()` can be as fast and sometimes faster than `LZ4_decompress_fast()`.
+ * Moreover, LZ4_decompress_fast() is not protected vs malformed input, as it doesn't perform full validation of compressed data.
+ * As a consequence, this function is no longer recommended, and may be deprecated in future versions.
+ * It's only remaining specificity is that it can decompress data without knowing its compressed size.
+ *
+ * originalSize : is the uncompressed size to regenerate.
+ * `dst` must be already allocated, its size must be >= 'originalSize' bytes.
+ * @return : number of bytes read from source buffer (== compressed size).
+ * If the source stream is detected malformed, the function stops decoding and returns a negative result.
+ * note : This function requires uncompressed originalSize to be known in advance.
+ * The function never writes past the output buffer.
+ * However, since it doesn't know its 'src' size, it may read past the intended input.
+ * Also, because match offsets are not validated during decoding,
+ * reads from 'src' may underflow.
+ * Use this function in trusted environment **only**.
+ */
+LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
+
+/*! LZ4_decompress_safe_partial() :
+ * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src',
+ * into destination buffer 'dst' of size 'dstCapacity'.
+ * Up to 'targetOutputSize' bytes will be decoded.
+ * The function stops decoding on reaching this objective,
+ * which can boost performance when only the beginning of a block is required.
+ *
+ * @return : the number of bytes decoded in `dst` (necessarily <= dstCapacity)
+ * If source stream is detected malformed, function returns a negative result.
+ *
+ * Note : @return can be < targetOutputSize, if compressed block contains less data.
+ *
+ * Note 2 : this function features 2 parameters, targetOutputSize and dstCapacity,
+ * and expects targetOutputSize <= dstCapacity.
+ * It effectively stops decoding on reaching targetOutputSize,
+ * so dstCapacity is kind of redundant.
+ * This is because in a previous version of this function,
+ * decoding operation would not "break" a sequence in the middle.
+ * As a consequence, there was no guarantee that decoding would stop at exactly targetOutputSize,
+ * it could write more bytes, though only up to dstCapacity.
+ * Some "margin" used to be required for this operation to work properly.
+ * This is no longer necessary.
+ * The function nonetheless keeps its signature, in an effort to not break API.
+ */
+LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity);
/*-*********************************************
* Streaming Compression Functions
***********************************************/
-typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */
+typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */
/*! LZ4_createStream() and LZ4_freeStream() :
* LZ4_createStream() will allocate and initialize an `LZ4_stream_t` structure.
@@ -244,87 +268,219 @@ LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr);
/*! LZ4_resetStream() :
* An LZ4_stream_t structure can be allocated once and re-used multiple times.
- * Use this function to init an allocated `LZ4_stream_t` structure and start a new compression.
+ * Use this function to start compressing a new stream.
*/
LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
/*! LZ4_loadDict() :
- * Use this function to load a static dictionary into LZ4_stream.
+ * Use this function to load a static dictionary into LZ4_stream_t.
* Any previous data will be forgotten, only 'dictionary' will remain in memory.
- * Loading a size of 0 is allowed.
- * Return : dictionary size, in bytes (necessarily <= 64 KB)
+ * Loading a size of 0 is allowed, and is the same as reset.
+ * @return : dictionary size, in bytes (necessarily <= 64 KB)
*/
LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
/*! LZ4_compress_fast_continue() :
- * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
- * Important : Previous data blocks are assumed to remain present and unmodified !
+ * Compress 'src' content using data from previously compressed blocks, for better compression ratio.
* 'dst' buffer must be already allocated.
* If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function @return==0.
- * After an error, the stream status is invalid, it can only be reset or freed.
+ *
+ * @return : size of compressed block
+ * or 0 if there is an error (typically, cannot fit into 'dst').
+ *
+ * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block.
+ * Each block has precise boundaries.
+ * It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together.
+ * Each block must be decompressed separately, calling LZ4_decompress_*() with associated metadata.
+ *
+ * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory!
+ *
+ * Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB.
+ * Make sure that buffers are separated, by at least one byte.
+ * This construction ensures that each block only depends on previous block.
+ *
+ * Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.
+ *
+ * Note 5 : After an error, the stream status is invalid, it can only be reset or freed.
*/
LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
/*! LZ4_saveDict() :
- * If previously compressed data block is not guaranteed to remain available at its current memory location,
+ * If last 64KB data cannot be guaranteed to remain available at its current memory location,
* save it into a safer place (char* safeBuffer).
- * Note : it's not necessary to call LZ4_loadDict() after LZ4_saveDict(), dictionary is immediately usable.
- * @return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
+ * This is schematically equivalent to a memcpy() followed by LZ4_loadDict(),
+ * but is much faster, because LZ4_saveDict() doesn't need to rebuild tables.
+ * @return : saved dictionary size in bytes (necessarily <= maxDictSize), or 0 if error.
*/
-LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
+LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int maxDictSize);
/*-**********************************************
* Streaming Decompression Functions
* Bufferless synchronous API
************************************************/
-typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* incomplete type (defined later) */
+typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* tracking context */
/*! LZ4_createStreamDecode() and LZ4_freeStreamDecode() :
- * creation / destruction of streaming decompression tracking structure */
+ * creation / destruction of streaming decompression tracking context.
+ * A tracking context can be re-used multiple times.
+ */
LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
/*! LZ4_setStreamDecode() :
- * Use this function to instruct where to find the dictionary.
- * Setting a size of 0 is allowed (same effect as reset).
- * @return : 1 if OK, 0 if error
+ * An LZ4_streamDecode_t context can be allocated once and re-used multiple times.
+ * Use this function to start decompression of a new stream of blocks.
+ * A dictionary can optionally be set. Use NULL or size 0 for a reset order.
+ * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.
+ * @return : 1 if OK, 0 if error
*/
LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
+/*! LZ4_decoderRingBufferSize() : v1.8.2
+ * Note : in a ring buffer scenario (optional),
+ * blocks are presumed decompressed next to each other
+ * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize),
+ * at which stage it resumes from beginning of ring buffer.
+ * When setting such a ring buffer for streaming decompression,
+ * provides the minimum size of this ring buffer
+ * to be compatible with any source respecting maxBlockSize condition.
+ * @return : minimum ring buffer size,
+ * or 0 if there is an error (invalid maxBlockSize).
+ */
+LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize);
+#define LZ4_DECODER_RING_BUFFER_SIZE(mbs) (65536 + 14 + (mbs)) /* for static allocation; mbs presumed valid */
+
/*! LZ4_decompress_*_continue() :
- * These decoding functions allow decompression of multiple blocks in "streaming" mode.
- * Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
- * In the case of a ring buffers, decoding buffer must be either :
- * - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
- * In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
- * - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
- * maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
+ * These decoding functions allow decompression of consecutive blocks in "streaming" mode.
+ * A block is an unsplittable entity, it must be presented entirely to a decompression function.
+ * Decompression functions only accepts one block at a time.
+ * The last 64KB of previously decoded data *must* remain available and unmodified at the memory position where they were decoded.
+ * If less than 64KB of data has been decoded, all the data must be present.
+ *
+ * Special : if decompression side sets a ring buffer, it must respect one of the following conditions :
+ * - Decompression buffer size is _at least_ LZ4_decoderRingBufferSize(maxBlockSize).
+ * maxBlockSize is the maximum size of any single block. It can have any value > 16 bytes.
+ * In which case, encoding and decoding buffers do not need to be synchronized.
+ * Actually, data can be produced by any source compliant with LZ4 format specification, and respecting maxBlockSize.
+ * - Synchronized mode :
+ * Decompression buffer size is _exactly_ the same as compression buffer size,
+ * and follows exactly same update rule (block boundaries at same positions),
+ * and decoding function is provided with exact decompressed size of each block (exception for last block of the stream),
+ * _then_ decoding & encoding ring buffer can have any size, including small ones ( < 64 KB).
+ * - Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes.
* In which case, encoding and decoding buffers do not need to be synchronized,
* and encoding ring buffer can have any size, including small ones ( < 64 KB).
- * - _At least_ 64 KB + 8 bytes + maxBlockSize.
- * In which case, encoding and decoding buffers do not need to be synchronized,
- * and encoding ring buffer can have any size, including larger than decoding buffer.
- * Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
- * and indicate where it is saved using LZ4_setStreamDecode()
+ *
+ * Whenever these conditions are not possible,
+ * save the last 64KB of decoded data into a safe buffer where it can't be modified during decompression,
+ * then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block.
*/
-LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
-LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
+LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int srcSize, int dstCapacity);
+LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
/*! LZ4_decompress_*_usingDict() :
* These decoding functions work the same as
* a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue()
* They are stand-alone, and don't need an LZ4_streamDecode_t structure.
+ * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.
*/
-LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
-LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, const char* dictStart, int dictSize);
+LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* src, char* dst, int srcSize, int dstCapcity, const char* dictStart, int dictSize);
+LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
/*^**********************************************
* !!!!!! STATIC LINKING ONLY !!!!!!
***********************************************/
+
+/*-************************************
+ * Unstable declarations
+ **************************************
+ * Declarations in this section should be considered unstable.
+ * Use at your own peril, etc., etc.
+ * They may be removed in the future.
+ * Their signatures may change.
+ **************************************/
+
+#ifdef LZ4_STATIC_LINKING_ONLY
+
+/*! LZ4_resetStream_fast() :
+ * Use this, like LZ4_resetStream(), to prepare a context for a new chain of
+ * calls to a streaming API (e.g., LZ4_compress_fast_continue()).
+ *
+ * Note:
+ * Using this in advance of a non- streaming-compression function is redundant,
+ * and potentially bad for performance, since they all perform their own custom
+ * reset internally.
+ *
+ * Differences from LZ4_resetStream():
+ * When an LZ4_stream_t is known to be in a internally coherent state,
+ * it can often be prepared for a new compression with almost no work, only
+ * sometimes falling back to the full, expensive reset that is always required
+ * when the stream is in an indeterminate state (i.e., the reset performed by
+ * LZ4_resetStream()).
+ *
+ * LZ4_streams are guaranteed to be in a valid state when:
+ * - returned from LZ4_createStream()
+ * - reset by LZ4_resetStream()
+ * - memset(stream, 0, sizeof(LZ4_stream_t)), though this is discouraged
+ * - the stream was in a valid state and was reset by LZ4_resetStream_fast()
+ * - the stream was in a valid state and was then used in any compression call
+ * that returned success
+ * - the stream was in an indeterminate state and was used in a compression
+ * call that fully reset the state (e.g., LZ4_compress_fast_extState()) and
+ * that returned success
+ *
+ * When a stream isn't known to be in a valid state, it is not safe to pass to
+ * any fastReset or streaming function. It must first be cleansed by the full
+ * LZ4_resetStream().
+ */
+LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr);
+
+/*! LZ4_compress_fast_extState_fastReset() :
+ * A variant of LZ4_compress_fast_extState().
+ *
+ * Using this variant avoids an expensive initialization step. It is only safe
+ * to call if the state buffer is known to be correctly initialized already
+ * (see above comment on LZ4_resetStream_fast() for a definition of "correctly
+ * initialized"). From a high level, the difference is that this function
+ * initializes the provided state with a call to something like
+ * LZ4_resetStream_fast() while LZ4_compress_fast_extState() starts with a
+ * call to LZ4_resetStream().
+ */
+LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
+
+/*! LZ4_attach_dictionary() :
+ * This is an experimental API that allows for the efficient use of a
+ * static dictionary many times.
+ *
+ * Rather than re-loading the dictionary buffer into a working context before
+ * each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a
+ * working LZ4_stream_t, this function introduces a no-copy setup mechanism,
+ * in which the working stream references the dictionary stream in-place.
+ *
+ * Several assumptions are made about the state of the dictionary stream.
+ * Currently, only streams which have been prepared by LZ4_loadDict() should
+ * be expected to work.
+ *
+ * Alternatively, the provided dictionary stream pointer may be NULL, in which
+ * case any existing dictionary stream is unset.
+ *
+ * If a dictionary is provided, it replaces any pre-existing stream history.
+ * The dictionary contents are the only history that can be referenced and
+ * logically immediately precede the data compressed in the first subsequent
+ * compression call.
+ *
+ * The dictionary will only remain attached to the working stream through the
+ * first compression call, at the end of which it is cleared. The dictionary
+ * stream (and source buffer) must remain in-place / accessible / unchanged
+ * through the completion of the first compression call on the stream.
+ */
+LZ4LIB_API void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream);
+
+#endif
+
/*-************************************
* Private definitions
**************************************
@@ -339,14 +495,16 @@ LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* source, char* dest, in
#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#include <stdint.h>
-typedef struct {
+typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
+struct LZ4_stream_t_internal {
uint32_t hashTable[LZ4_HASH_SIZE_U32];
uint32_t currentOffset;
- uint32_t initCheck;
+ uint16_t initCheck;
+ uint16_t tableType;
const uint8_t* dictionary;
- uint8_t* bufferStart; /* obsolete, used for slideInputBuffer */
+ const LZ4_stream_t_internal* dictCtx;
uint32_t dictSize;
-} LZ4_stream_t_internal;
+};
typedef struct {
const uint8_t* externalDict;
@@ -357,14 +515,16 @@ typedef struct {
#else
-typedef struct {
+typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
+struct LZ4_stream_t_internal {
unsigned int hashTable[LZ4_HASH_SIZE_U32];
unsigned int currentOffset;
- unsigned int initCheck;
+ unsigned short initCheck;
+ unsigned short tableType;
const unsigned char* dictionary;
- unsigned char* bufferStart; /* obsolete, used for slideInputBuffer */
+ const LZ4_stream_t_internal* dictCtx;
unsigned int dictSize;
-} LZ4_stream_t_internal;
+};
typedef struct {
const unsigned char* externalDict;
@@ -436,26 +596,34 @@ union LZ4_streamDecode_u {
#endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
/* Obsolete compression functions */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress (const char* source, char* dest, int sourceSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* source, char* dest, int sourceSize);
+LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
+LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
+LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
+LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
/* Obsolete decompression functions */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_fast() instead") int LZ4_uncompress (const char* source, char* dest, int outputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_safe() instead") int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
-
-/* Obsolete streaming functions; use new streaming interface whenever possible */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state);
+LZ4_DEPRECATED("use LZ4_decompress_fast() instead") LZ4LIB_API int LZ4_uncompress (const char* source, char* dest, int outputSize);
+LZ4_DEPRECATED("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
+
+/* Obsolete streaming functions; degraded functionality; do not use!
+ *
+ * In order to perform streaming compression, these functions depended on data
+ * that is no longer tracked in the state. They have been preserved as well as
+ * possible: using them will still produce a correct output. However, they don't
+ * actually retain any history between compression calls. The compression ratio
+ * achieved will therefore be no better than compressing each chunk
+ * independently.
+ */
+LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API void* LZ4_create (char* inputBuffer);
+LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API int LZ4_sizeofStreamState(void);
+LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer);
+LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state);
/* Obsolete streaming decoding functions */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
+LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
+LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
#endif /* LZ4_H_2983827168210 */
diff --git a/lib/lz4frame.c b/lib/lz4frame.c
index 340870877ed..08bf0faee1d 100644
--- a/lib/lz4frame.c
+++ b/lib/lz4frame.c
@@ -46,11 +46,25 @@ You can contact the author at :
#endif
+/*-************************************
+* Tuning parameters
+**************************************/
+/*
+ * LZ4F_HEAPMODE :
+ * Select how default compression functions will allocate memory for their hash table,
+ * in memory stack (0:default, fastest), or in memory heap (1:requires malloc()).
+ */
+#ifndef LZ4F_HEAPMODE
+# define LZ4F_HEAPMODE 0
+#endif
+
+
/*-************************************
* Memory routines
**************************************/
#include <stdlib.h> /* malloc, calloc, free */
-#define ALLOCATOR(s) calloc(1,s)
+#define ALLOC(s) malloc(s)
+#define ALLOC_AND_ZERO(s) calloc(1,s)
#define FREEMEM free
#include <string.h> /* memset, memcpy, memmove */
#define MEM_INIT memset
@@ -59,7 +73,9 @@ You can contact the author at :
/*-************************************
* Includes
**************************************/
-#include "lz4frame_static.h"
+#define LZ4F_STATIC_LINKING_ONLY
+#include "lz4frame.h"
+#define LZ4_STATIC_LINKING_ONLY
#include "lz4.h"
#define LZ4_HC_STATIC_LINKING_ONLY
#include "lz4hc.h"
@@ -70,8 +86,29 @@ You can contact the author at :
/*-************************************
* Debug
**************************************/
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1)
+# include <assert.h>
+#else
+# ifndef assert
+# define assert(condition) ((void)0)
+# endif
+#endif
+
#define LZ4F_STATIC_ASSERT(c) { enum { LZ4F_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) && !defined(DEBUGLOG)
+# include <stdio.h>
+static int g_debuglog_enable = 1;
+# define DEBUGLOG(l, ...) { \
+ if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \
+ fprintf(stderr, __FILE__ ": "); \
+ fprintf(stderr, __VA_ARGS__); \
+ fprintf(stderr, " \n"); \
+ } }
+#else
+# define DEBUGLOG(l, ...) {} /* disabled */
+#endif
+
/*-************************************
* Basic Types
@@ -180,7 +217,8 @@ typedef struct LZ4F_cctx_s
U64 totalInSize;
XXH32_state_t xxh;
void* lz4CtxPtr;
- U32 lz4CtxLevel; /* 0: unallocated; 1: LZ4_stream_t; 3: LZ4_streamHC_t */
+ U16 lz4CtxAlloc; /* sized for: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
+ U16 lz4CtxState; /* in use as: 0 = none, 1 = lz4 ctx, 2 = lz4hc ctx */
} LZ4F_cctx_t;
@@ -271,7 +309,7 @@ static size_t LZ4F_compressBound_internal(size_t srcSize,
size_t alreadyBuffered)
{
LZ4F_preferences_t prefsNull;
- memset(&prefsNull, 0, sizeof(prefsNull));
+ MEM_INIT(&prefsNull, 0, sizeof(prefsNull));
prefsNull.frameInfo.contentChecksumFlag = LZ4F_contentChecksumEnabled; /* worst case */
{ const LZ4F_preferences_t* const prefsPtr = (preferencesPtr==NULL) ? &prefsNull : preferencesPtr;
U32 const flush = prefsPtr->autoFlush | (srcSize==0);
@@ -281,7 +319,7 @@ static size_t LZ4F_compressBound_internal(size_t srcSize,
size_t const bufferedSize = MIN(alreadyBuffered, maxBuffered);
size_t const maxSrcSize = srcSize + bufferedSize;
unsigned const nbFullBlocks = (unsigned)(maxSrcSize / blockSize);
- size_t const partialBlockSize = (srcSize - (srcSize==0)) & (blockSize-1); /* 0 => -1 == MAX => blockSize-1 */
+ size_t const partialBlockSize = maxSrcSize & (blockSize-1);
size_t const lastBlockSize = flush ? partialBlockSize : 0;
unsigned const nbBlocks = nbFullBlocks + (lastBlockSize>0);
@@ -300,7 +338,7 @@ size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* prefere
size_t const headerSize = maxFHSize; /* max header size, including optional fields */
if (preferencesPtr!=NULL) prefs = *preferencesPtr;
- else memset(&prefs, 0, sizeof(prefs));
+ else MEM_INIT(&prefs, 0, sizeof(prefs));
prefs.autoFlush = 1;
return headerSize + LZ4F_compressBound_internal(srcSize, &prefs, 0);;
@@ -316,27 +354,22 @@ size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* prefere
* @return : number of bytes written into dstBuffer,
* or an error code if it fails (can be tested using LZ4F_isError())
*/
-size_t LZ4F_compressFrame_usingCDict(void* dstBuffer, size_t dstCapacity,
+size_t LZ4F_compressFrame_usingCDict(LZ4F_cctx* cctx,
+ void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
const LZ4F_CDict* cdict,
const LZ4F_preferences_t* preferencesPtr)
{
- LZ4F_cctx_t cctxI;
- LZ4_stream_t lz4ctx;
LZ4F_preferences_t prefs;
LZ4F_compressOptions_t options;
BYTE* const dstStart = (BYTE*) dstBuffer;
BYTE* dstPtr = dstStart;
BYTE* const dstEnd = dstStart + dstCapacity;
- memset(&cctxI, 0, sizeof(cctxI));
- cctxI.version = LZ4F_VERSION;
- cctxI.maxBufferSize = 5 MB; /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
-
if (preferencesPtr!=NULL)
prefs = *preferencesPtr;
else
- memset(&prefs, 0, sizeof(prefs));
+ MEM_INIT(&prefs, 0, sizeof(prefs));
if (prefs.frameInfo.contentSize != 0)
prefs.frameInfo.contentSize = (U64)srcSize; /* auto-correct content size if selected (!=0) */
@@ -345,32 +378,24 @@ size_t LZ4F_compressFrame_usingCDict(void* dstBuffer, size_t dstCapacity,
if (srcSize <= LZ4F_getBlockSize(prefs.frameInfo.blockSizeID))
prefs.frameInfo.blockMode = LZ4F_blockIndependent; /* only one block => no need for inter-block link */
- if (prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
- cctxI.lz4CtxPtr = &lz4ctx;
- cctxI.lz4CtxLevel = 1;
- } /* fast compression context pre-created on stack */
-
- memset(&options, 0, sizeof(options));
+ MEM_INIT(&options, 0, sizeof(options));
options.stableSrc = 1;
if (dstCapacity < LZ4F_compressFrameBound(srcSize, &prefs)) /* condition to guarantee success */
return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
- { size_t const headerSize = LZ4F_compressBegin_usingCDict(&cctxI, dstBuffer, dstCapacity, cdict, &prefs); /* write header */
+ { size_t const headerSize = LZ4F_compressBegin_usingCDict(cctx, dstBuffer, dstCapacity, cdict, &prefs); /* write header */
if (LZ4F_isError(headerSize)) return headerSize;
dstPtr += headerSize; /* header size */ }
- { size_t const cSize = LZ4F_compressUpdate(&cctxI, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options);
+ { size_t const cSize = LZ4F_compressUpdate(cctx, dstPtr, dstEnd-dstPtr, srcBuffer, srcSize, &options);
if (LZ4F_isError(cSize)) return cSize;
dstPtr += cSize; }
- { size_t const tailSize = LZ4F_compressEnd(&cctxI, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */
+ { size_t const tailSize = LZ4F_compressEnd(cctx, dstPtr, dstEnd-dstPtr, &options); /* flush last block, and generate suffix */
if (LZ4F_isError(tailSize)) return tailSize;
dstPtr += tailSize; }
- if (prefs.compressionLevel >= LZ4HC_CLEVEL_MIN) /* Ctx allocation only for lz4hc */
- FREEMEM(cctxI.lz4CtxPtr);
-
return (dstPtr - dstStart);
}
@@ -386,9 +411,44 @@ size_t LZ4F_compressFrame(void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
const LZ4F_preferences_t* preferencesPtr)
{
- return LZ4F_compressFrame_usingCDict(dstBuffer, dstCapacity,
- srcBuffer, srcSize,
- NULL, preferencesPtr);
+ size_t result;
+#if (LZ4F_HEAPMODE)
+ LZ4F_cctx_t *cctxPtr;
+ result = LZ4F_createCompressionContext(&cctxPtr, LZ4F_VERSION);
+ if (LZ4F_isError(result)) return result;
+#else
+ LZ4F_cctx_t cctx;
+ LZ4_stream_t lz4ctx;
+ LZ4F_cctx_t *cctxPtr = &cctx;
+
+ DEBUGLOG(4, "LZ4F_compressFrame");
+ MEM_INIT(&cctx, 0, sizeof(cctx));
+ cctx.version = LZ4F_VERSION;
+ cctx.maxBufferSize = 5 MB; /* mess with real buffer size to prevent dynamic allocation; works only because autoflush==1 & stableSrc==1 */
+ if (preferencesPtr == NULL ||
+ preferencesPtr->compressionLevel < LZ4HC_CLEVEL_MIN)
+ {
+ LZ4_resetStream(&lz4ctx);
+ cctxPtr->lz4CtxPtr = &lz4ctx;
+ cctxPtr->lz4CtxAlloc = 1;
+ cctxPtr->lz4CtxState = 1;
+ }
+#endif
+
+ result = LZ4F_compressFrame_usingCDict(cctxPtr, dstBuffer, dstCapacity,
+ srcBuffer, srcSize,
+ NULL, preferencesPtr);
+
+#if (LZ4F_HEAPMODE)
+ LZ4F_freeCompressionContext(cctxPtr);
+#else
+ if (preferencesPtr != NULL &&
+ preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN)
+ {
+ FREEMEM(cctxPtr->lz4CtxPtr);
+ }
+#endif
+ return result;
}
@@ -411,13 +471,14 @@ struct LZ4F_CDict_s {
LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize)
{
const char* dictStart = (const char*)dictBuffer;
- LZ4F_CDict* cdict = (LZ4F_CDict*) malloc(sizeof(*cdict));
+ LZ4F_CDict* cdict = (LZ4F_CDict*) ALLOC(sizeof(*cdict));
+ DEBUGLOG(4, "LZ4F_createCDict");
if (!cdict) return NULL;
if (dictSize > 64 KB) {
dictStart += dictSize - 64 KB;
dictSize = 64 KB;
}
- cdict->dictContent = ALLOCATOR(dictSize);
+ cdict->dictContent = ALLOC(dictSize);
cdict->fastCtx = LZ4_createStream();
cdict->HCCtx = LZ4_createStreamHC();
if (!cdict->dictContent || !cdict->fastCtx || !cdict->HCCtx) {
@@ -425,9 +486,8 @@ LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize)
return NULL;
}
memcpy(cdict->dictContent, dictStart, dictSize);
- LZ4_resetStream(cdict->fastCtx);
LZ4_loadDict (cdict->fastCtx, (const char*)cdict->dictContent, (int)dictSize);
- LZ4_resetStreamHC(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT);
+ LZ4_setCompressionLevel(cdict->HCCtx, LZ4HC_CLEVEL_DEFAULT);
LZ4_loadDictHC(cdict->HCCtx, (const char*)cdict->dictContent, (int)dictSize);
return cdict;
}
@@ -456,7 +516,7 @@ void LZ4F_freeCDict(LZ4F_CDict* cdict)
*/
LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_compressionContext_t* LZ4F_compressionContextPtr, unsigned version)
{
- LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)ALLOCATOR(sizeof(LZ4F_cctx_t));
+ LZ4F_cctx_t* const cctxPtr = (LZ4F_cctx_t*)ALLOC_AND_ZERO(sizeof(LZ4F_cctx_t));
if (cctxPtr==NULL) return err0r(LZ4F_ERROR_allocation_failed);
cctxPtr->version = version;
@@ -482,6 +542,36 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_compressionContext_t LZ4F_comp
}
+/**
+ * This function prepares the internal LZ4(HC) stream for a new compression,
+ * resetting the context and attaching the dictionary, if there is one.
+ *
+ * It needs to be called at the beginning of each independent compression
+ * stream (i.e., at the beginning of a frame in blockLinked mode, or at the
+ * beginning of each block in blockIndependent mode).
+ */
+static void LZ4F_initStream(void* ctx,
+ const LZ4F_CDict* cdict,
+ int level,
+ LZ4F_blockMode_t blockMode) {
+ if (level < LZ4HC_CLEVEL_MIN) {
+ if (cdict != NULL || blockMode == LZ4F_blockLinked) {
+ /* In these cases, we will call LZ4_compress_fast_continue(),
+ * which needs an already reset context. Otherwise, we'll call a
+ * one-shot API. The non-continued APIs internally perform their own
+ * resets at the beginning of their calls, where they know what
+ * tableType they need the context to be in. So in that case this
+ * would be misguided / wasted work. */
+ LZ4_resetStream_fast((LZ4_stream_t*)ctx);
+ }
+ LZ4_attach_dictionary((LZ4_stream_t *)ctx, cdict ? cdict->fastCtx : NULL);
+ } else {
+ LZ4_resetStreamHC_fast((LZ4_streamHC_t*)ctx, level);
+ LZ4_attach_HC_dictionary((LZ4_streamHC_t *)ctx, cdict ? cdict->HCCtx : NULL);
+ }
+}
+
+
/*! LZ4F_compressBegin_usingCDict() :
* init streaming compression and writes frame header into dstBuffer.
* dstBuffer must be >= LZ4F_HEADER_SIZE_MAX bytes.
@@ -499,21 +589,33 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
BYTE* headerStart;
if (dstCapacity < maxFHSize) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
- memset(&prefNull, 0, sizeof(prefNull));
+ MEM_INIT(&prefNull, 0, sizeof(prefNull));
if (preferencesPtr == NULL) preferencesPtr = &prefNull;
cctxPtr->prefs = *preferencesPtr;
/* Ctx Management */
- { U32 const tableID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2; /* 0:nothing ; 1:LZ4 table ; 2:HC tables */
- if (cctxPtr->lz4CtxLevel < tableID) {
+ { U16 const ctxTypeID = (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) ? 1 : 2;
+ if (cctxPtr->lz4CtxAlloc < ctxTypeID) {
FREEMEM(cctxPtr->lz4CtxPtr);
- if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
+ if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
cctxPtr->lz4CtxPtr = (void*)LZ4_createStream();
- else
+ } else {
cctxPtr->lz4CtxPtr = (void*)LZ4_createStreamHC();
+ }
if (cctxPtr->lz4CtxPtr == NULL) return err0r(LZ4F_ERROR_allocation_failed);
- cctxPtr->lz4CtxLevel = tableID;
- } }
+ cctxPtr->lz4CtxAlloc = ctxTypeID;
+ cctxPtr->lz4CtxState = ctxTypeID;
+ } else if (cctxPtr->lz4CtxState != ctxTypeID) {
+ /* otherwise, a sufficient buffer is allocated, but we need to
+ * reset it to the correct context type */
+ if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
+ LZ4_resetStream((LZ4_stream_t *) cctxPtr->lz4CtxPtr);
+ } else {
+ LZ4_resetStreamHC((LZ4_streamHC_t *) cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
+ }
+ cctxPtr->lz4CtxState = ctxTypeID;
+ }
+ }
/* Buffer Management */
if (cctxPtr->prefs.frameInfo.blockSizeID == 0)
@@ -527,7 +629,7 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
if (cctxPtr->maxBufferSize < requiredBuffSize) {
cctxPtr->maxBufferSize = 0;
FREEMEM(cctxPtr->tmpBuff);
- cctxPtr->tmpBuff = (BYTE*)ALLOCATOR(requiredBuffSize);
+ cctxPtr->tmpBuff = (BYTE*)ALLOC_AND_ZERO(requiredBuffSize);
if (cctxPtr->tmpBuff == NULL) return err0r(LZ4F_ERROR_allocation_failed);
cctxPtr->maxBufferSize = requiredBuffSize;
} }
@@ -539,19 +641,10 @@ size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctxPtr,
cctxPtr->cdict = cdict;
if (cctxPtr->prefs.frameInfo.blockMode == LZ4F_blockLinked) {
/* frame init only for blockLinked : blockIndependent will be init at each block */
- if (cdict) {
- if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN) {
- memcpy(cctxPtr->lz4CtxPtr, cdict->fastCtx, sizeof(*cdict->fastCtx));
- } else {
- memcpy(cctxPtr->lz4CtxPtr, cdict->HCCtx, sizeof(*cdict->HCCtx));
- LZ4_setCompressionLevel((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, cctxPtr->prefs.compressionLevel);
- }
- } else {
- if (cctxPtr->prefs.compressionLevel < LZ4HC_CLEVEL_MIN)
- LZ4_resetStream((LZ4_stream_t*)(cctxPtr->lz4CtxPtr));
- else
- LZ4_resetStreamHC((LZ4_streamHC_t*)(cctxPtr->lz4CtxPtr), cctxPtr->prefs.compressionLevel);
- }
+ LZ4F_initStream(cctxPtr->lz4CtxPtr, cdict, cctxPtr->prefs.compressionLevel, LZ4F_blockLinked);
+ }
+ if (preferencesPtr->compressionLevel >= LZ4HC_CLEVEL_MIN) {
+ LZ4_favorDecompressionSpeed((LZ4_streamHC_t*)cctxPtr->lz4CtxPtr, (int)preferencesPtr->favorDecSpeed);
}
/* Magic Number */
@@ -604,10 +697,10 @@ size_t LZ4F_compressBegin(LZ4F_cctx* cctxPtr,
}
-/* LZ4F_compressBound() :
- * @ return size of Dst buffer given a srcSize to handle worst case situations.
- * The LZ4F_frameInfo_t structure is optional : if NULL, preferences will be set to cover worst case situations.
- * This function cannot fail.
+/* LZ4F_compressBound() :
+ * @return minimum capacity of dstBuffer for a given srcSize to handle worst case scenario.
+ * LZ4F_preferences_t structure is optional : if NULL, preferences will be set to cover worst case scenario.
+ * This function cannot fail.
*/
size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr)
{
@@ -645,29 +738,29 @@ static size_t LZ4F_makeBlock(void* dst, const void* src, size_t srcSize,
static int LZ4F_compressBlock(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
{
- int const acceleration = (level < -1) ? -level : 1;
+ int const acceleration = (level < 0) ? -level + 1 : 1;
+ LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
if (cdict) {
- memcpy(ctx, cdict->fastCtx, sizeof(*cdict->fastCtx));
return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
+ } else {
+ return LZ4_compress_fast_extState_fastReset(ctx, src, dst, srcSize, dstCapacity, acceleration);
}
- return LZ4_compress_fast_extState(ctx, src, dst, srcSize, dstCapacity, acceleration);
}
static int LZ4F_compressBlock_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
{
- int const acceleration = (level < -1) ? -level : 1;
+ int const acceleration = (level < 0) ? -level + 1 : 1;
(void)cdict; /* init once at beginning of frame */
return LZ4_compress_fast_continue((LZ4_stream_t*)ctx, src, dst, srcSize, dstCapacity, acceleration);
}
static int LZ4F_compressBlockHC(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
{
+ LZ4F_initStream(ctx, cdict, level, LZ4F_blockIndependent);
if (cdict) {
- memcpy(ctx, cdict->HCCtx, sizeof(*cdict->HCCtx));
- LZ4_setCompressionLevel((LZ4_streamHC_t*)ctx, level);
return LZ4_compress_HC_continue((LZ4_streamHC_t*)ctx, src, dst, srcSize, dstCapacity);
}
- return LZ4_compress_HC_extStateHC(ctx, src, dst, srcSize, dstCapacity, level);
+ return LZ4_compress_HC_extStateHC_fastReset(ctx, src, dst, srcSize, dstCapacity, level);
}
static int LZ4F_compressBlockHC_continue(void* ctx, const char* src, char* dst, int srcSize, int dstCapacity, int level, const LZ4F_CDict* cdict)
@@ -716,10 +809,12 @@ size_t LZ4F_compressUpdate(LZ4F_cctx* cctxPtr,
LZ4F_lastBlockStatus lastBlockCompressed = notDone;
compressFunc_t const compress = LZ4F_selectCompression(cctxPtr->prefs.frameInfo.blockMode, cctxPtr->prefs.compressionLevel);
+ DEBUGLOG(4, "LZ4F_compressUpdate (srcSize=%zu)", srcSize);
if (cctxPtr->cStage != 1) return err0r(LZ4F_ERROR_GENERIC);
- if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize)) return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
- memset(&cOptionsNull, 0, sizeof(cOptionsNull));
+ if (dstCapacity < LZ4F_compressBound_internal(srcSize, &(cctxPtr->prefs), cctxPtr->tmpInSize))
+ return err0r(LZ4F_ERROR_dstMaxSize_tooSmall);
+ MEM_INIT(&cOptionsNull, 0, sizeof(cOptionsNull));
if (compressOptionsPtr == NULL) compressOptionsPtr = &cOptionsNull;
/* complete tmp buffer */
@@ -887,8 +982,7 @@ typedef enum {
dstage_getBlockHeader, dstage_storeBlockHeader,
dstage_copyDirect, dstage_getBlockChecksum,
dstage_getCBlock, dstage_storeCBlock,
- dstage_decodeCBlock, dstage_decodeCBlock_intoDst,
- dstage_decodeCBlock_intoTmp, dstage_flushOut,
+ dstage_flushOut,
dstage_getSuffix, dstage_storeSuffix,
dstage_getSFrameSize, dstage_storeSFrameSize,
dstage_skipSkippable
@@ -924,7 +1018,7 @@ struct LZ4F_dctx_s {
*/
LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** LZ4F_decompressionContextPtr, unsigned versionNumber)
{
- LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOCATOR(sizeof(LZ4F_dctx));
+ LZ4F_dctx* const dctx = (LZ4F_dctx*)ALLOC_AND_ZERO(sizeof(LZ4F_dctx));
if (dctx==NULL) return err0r(LZ4F_ERROR_GENERIC);
dctx->version = versionNumber;
@@ -996,7 +1090,7 @@ static size_t LZ4F_decodeHeader(LZ4F_dctx* dctx, const void* src, size_t srcSize
/* need to decode header to get frameInfo */
if (srcSize < minFHSize) return err0r(LZ4F_ERROR_frameHeader_incomplete); /* minimal frame header size */
- memset(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo));
+ MEM_INIT(&(dctx->frameInfo), 0, sizeof(dctx->frameInfo));
/* special case : skippable frames */
if ((LZ4F_readLE32(srcPtr) & 0xFFFFFFF0U) == LZ4F_MAGIC_SKIPPABLE_START) {
@@ -1129,24 +1223,31 @@ LZ4F_errorCode_t LZ4F_getFrameInfo(LZ4F_dctx* dctx, LZ4F_frameInfo_t* frameInfoP
/* LZ4F_updateDict() :
* only used for LZ4F_blockLinked mode */
-static void LZ4F_updateDict(LZ4F_dctx* dctx, const BYTE* dstPtr, size_t dstSize, const BYTE* dstPtr0, unsigned withinTmp)
+static void LZ4F_updateDict(LZ4F_dctx* dctx,
+ const BYTE* dstPtr, size_t dstSize, const BYTE* dstBufferStart,
+ unsigned withinTmp)
{
if (dctx->dictSize==0)
dctx->dict = (const BYTE*)dstPtr; /* priority to dictionary continuity */
- if (dctx->dict + dctx->dictSize == dstPtr) { /* dictionary continuity */
+ if (dctx->dict + dctx->dictSize == dstPtr) { /* dictionary continuity, directly within dstBuffer */
dctx->dictSize += dstSize;
return;
}
- if (dstPtr - dstPtr0 + dstSize >= 64 KB) { /* dstBuffer large enough to become dictionary */
- dctx->dict = (const BYTE*)dstPtr0;
- dctx->dictSize = dstPtr - dstPtr0 + dstSize;
+ if (dstPtr - dstBufferStart + dstSize >= 64 KB) { /* history in dstBuffer becomes large enough to become dictionary */
+ dctx->dict = (const BYTE*)dstBufferStart;
+ dctx->dictSize = dstPtr - dstBufferStart + dstSize;
return;
}
- if ((withinTmp) && (dctx->dict == dctx->tmpOutBuffer)) {
- /* assumption : dctx->dict + dctx->dictSize == dctx->tmpOut + dctx->tmpOutStart */
+ assert(dstSize < 64 KB); /* if dstSize >= 64 KB, dictionary would be set into dstBuffer directly */
+
+ /* dstBuffer does not contain whole useful history (64 KB), so it must be saved within tmpOut */
+
+ if ((withinTmp) && (dctx->dict == dctx->tmpOutBuffer)) { /* continue history within tmpOutBuffer */
+ /* withinTmp expectation : content of [dstPtr,dstSize] is same as [dict+dictSize,dstSize], so we just extend it */
+ assert(dctx->dict + dctx->dictSize == dctx->tmpOut + dctx->tmpOutStart);
dctx->dictSize += dstSize;
return;
}
@@ -1167,7 +1268,7 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx, const BYTE* dstPtr, size_t dstSize,
if (dctx->dict == dctx->tmpOutBuffer) { /* copy dst into tmp to complete dict */
if (dctx->dictSize + dstSize > dctx->maxBufferSize) { /* tmp buffer not large enough */
- size_t const preserveSize = 64 KB - dstSize; /* note : dstSize < 64 KB */
+ size_t const preserveSize = 64 KB - dstSize;
memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
dctx->dictSize = preserveSize;
}
@@ -1177,7 +1278,7 @@ static void LZ4F_updateDict(LZ4F_dctx* dctx, const BYTE* dstPtr, size_t dstSize,
}
/* join dict & dest into tmp */
- { size_t preserveSize = 64 KB - dstSize; /* note : dstSize < 64 KB */
+ { size_t preserveSize = 64 KB - dstSize;
if (preserveSize > dctx->dictSize) preserveSize = dctx->dictSize;
memcpy(dctx->tmpOutBuffer, dctx->dict + dctx->dictSize - preserveSize, preserveSize);
memcpy(dctx->tmpOutBuffer + preserveSize, dstPtr, dstSize);
@@ -1223,7 +1324,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
size_t nextSrcSizeHint = 1;
- memset(&optionsNull, 0, sizeof(optionsNull));
+ MEM_INIT(&optionsNull, 0, sizeof(optionsNull));
if (decompressOptionsPtr==NULL) decompressOptionsPtr = &optionsNull;
*srcSizePtr = 0;
*dstSizePtr = 0;
@@ -1244,7 +1345,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
}
dctx->tmpInSize = 0;
if (srcEnd-srcPtr == 0) return minFHSize; /* 0-size input */
- dctx->tmpInTarget = minFHSize; /* minimum to attempt decode */
+ dctx->tmpInTarget = minFHSize; /* minimum size to decode header */
dctx->dStage = dstage_storeFrameHeader;
/* fall-through */
@@ -1253,29 +1354,32 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
dctx->tmpInSize += sizeToCopy;
srcPtr += sizeToCopy;
- if (dctx->tmpInSize < dctx->tmpInTarget) {
- nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize; /* rest of header + nextBlockHeader */
- doAnotherStage = 0; /* not enough src data, ask for some more */
- break;
- }
- { size_t const hSize = LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget); /* will update dStage appropriately */
- if (LZ4F_isError(hSize)) return hSize;
- }
+ }
+ if (dctx->tmpInSize < dctx->tmpInTarget) {
+ nextSrcSizeHint = (dctx->tmpInTarget - dctx->tmpInSize) + BHSize; /* rest of header + nextBlockHeader */
+ doAnotherStage = 0; /* not enough src data, ask for some more */
break;
}
+ { size_t const hSize = LZ4F_decodeHeader(dctx, dctx->header, dctx->tmpInTarget); /* will update dStage appropriately */
+ if (LZ4F_isError(hSize)) return hSize;
+ }
+ break;
case dstage_init:
if (dctx->frameInfo.contentChecksumFlag) XXH32_reset(&(dctx->xxh), 0);
/* internal buffers allocation */
- { size_t const bufferNeeded = dctx->maxBlockSize + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB) + 4 /* block checksum */;
+ { size_t const bufferNeeded = dctx->maxBlockSize
+ + ((dctx->frameInfo.blockMode==LZ4F_blockLinked) * 128 KB);
if (bufferNeeded > dctx->maxBufferSize) { /* tmp buffers too small */
dctx->maxBufferSize = 0; /* ensure allocation will be re-attempted on next entry*/
FREEMEM(dctx->tmpIn);
- dctx->tmpIn = (BYTE*)ALLOCATOR(dctx->maxBlockSize);
- if (dctx->tmpIn == NULL) return err0r(LZ4F_ERROR_allocation_failed);
+ dctx->tmpIn = (BYTE*)ALLOC(dctx->maxBlockSize + 4 /* block checksum */);
+ if (dctx->tmpIn == NULL)
+ return err0r(LZ4F_ERROR_allocation_failed);
FREEMEM(dctx->tmpOutBuffer);
- dctx->tmpOutBuffer= (BYTE*)ALLOCATOR(bufferNeeded);
- if (dctx->tmpOutBuffer== NULL) return err0r(LZ4F_ERROR_allocation_failed);
+ dctx->tmpOutBuffer= (BYTE*)ALLOC(bufferNeeded);
+ if (dctx->tmpOutBuffer== NULL)
+ return err0r(LZ4F_ERROR_allocation_failed);
dctx->maxBufferSize = bufferNeeded;
} }
dctx->tmpInSize = 0;
@@ -1299,18 +1403,20 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
if (dctx->dStage == dstage_storeBlockHeader) /* can be skipped */
case dstage_storeBlockHeader:
- { size_t sizeToCopy = BHSize - dctx->tmpInSize;
- if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
+ { size_t const remainingInput = (size_t)(srcEnd - srcPtr);
+ size_t const wantedData = BHSize - dctx->tmpInSize;
+ size_t const sizeToCopy = MIN(wantedData, remainingInput);
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
srcPtr += sizeToCopy;
dctx->tmpInSize += sizeToCopy;
+
if (dctx->tmpInSize < BHSize) { /* not enough input for cBlockSize */
nextSrcSizeHint = BHSize - dctx->tmpInSize;
doAnotherStage = 0;
break;
}
selectedIn = dctx->tmpIn;
- }
+ } /* if (dctx->dStage == dstage_storeBlockHeader) */
/* decode block header */
{ size_t const nextCBlockSize = LZ4F_readLE32(selectedIn) & 0x7FFFFFFFU;
@@ -1396,12 +1502,11 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
U32 const calcCRC = XXH32_digest(&dctx->blockChecksum);
if (readCRC != calcCRC)
return err0r(LZ4F_ERROR_blockChecksum_invalid);
- }
- }
+ } }
dctx->dStage = dstage_getBlockHeader; /* new block */
break;
- case dstage_getCBlock: /* entry from dstage_decodeCBlockSize */
+ case dstage_getCBlock:
if ((size_t)(srcEnd-srcPtr) < dctx->tmpInTarget) {
dctx->tmpInSize = 0;
dctx->dStage = dstage_storeCBlock;
@@ -1410,11 +1515,12 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
/* input large enough to read full block directly */
selectedIn = srcPtr;
srcPtr += dctx->tmpInTarget;
- dctx->dStage = dstage_decodeCBlock;
- break;
+ if (0) /* jump over next block */
case dstage_storeCBlock:
- { size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize, (size_t)(srcEnd-srcPtr));
+ { size_t const wantedData = dctx->tmpInTarget - dctx->tmpInSize;
+ size_t const inputLeft = (size_t)(srcEnd-srcPtr);
+ size_t const sizeToCopy = MIN(wantedData, inputLeft);
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
dctx->tmpInSize += sizeToCopy;
srcPtr += sizeToCopy;
@@ -1424,30 +1530,32 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
break;
}
selectedIn = dctx->tmpIn;
- dctx->dStage = dstage_decodeCBlock;
}
- /* fall-through */
- /* At this stage, input is large enough to decode a block */
- case dstage_decodeCBlock:
+ /* At this stage, input is large enough to decode a block */
if (dctx->frameInfo.blockChecksumFlag) {
dctx->tmpInTarget -= 4;
+ assert(selectedIn != NULL); /* selectedIn is defined at this stage (either srcPtr, or dctx->tmpIn) */
{ U32 const readBlockCrc = LZ4F_readLE32(selectedIn + dctx->tmpInTarget);
U32 const calcBlockCrc = XXH32(selectedIn, dctx->tmpInTarget, 0);
if (readBlockCrc != calcBlockCrc)
return err0r(LZ4F_ERROR_blockChecksum_invalid);
} }
- if ((size_t)(dstEnd-dstPtr) < dctx->maxBlockSize) /* not enough place into dst : decode into tmpOut */
- dctx->dStage = dstage_decodeCBlock_intoTmp;
- else
- dctx->dStage = dstage_decodeCBlock_intoDst;
- break;
- case dstage_decodeCBlock_intoDst:
- { int const decodedSize = LZ4_decompress_safe_usingDict(
+ if ((size_t)(dstEnd-dstPtr) >= dctx->maxBlockSize) {
+ const char* dict = (const char*)dctx->dict;
+ size_t dictSize = dctx->dictSize;
+ int decodedSize;
+ if (dict && dictSize > 1 GB) {
+ /* the dictSize param is an int, avoid truncation / sign issues */
+ dict += dictSize - 64 KB;
+ dictSize = 64 KB;
+ }
+ /* enough capacity in `dst` to decompress directly there */
+ decodedSize = LZ4_decompress_safe_usingDict(
(const char*)selectedIn, (char*)dstPtr,
(int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
- (const char*)dctx->dict, (int)dctx->dictSize);
+ dict, (int)dictSize);
if (decodedSize < 0) return err0r(LZ4F_ERROR_GENERIC); /* decompression failed */
if (dctx->frameInfo.contentChecksumFlag)
XXH32_update(&(dctx->xxh), dstPtr, decodedSize);
@@ -1463,9 +1571,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
break;
}
- case dstage_decodeCBlock_intoTmp:
/* not enough place into dst : decode into tmpOut */
-
/* ensure enough place for tmpOut */
if (dctx->frameInfo.blockMode == LZ4F_blockLinked) {
if (dctx->dict == dctx->tmpOutBuffer) {
@@ -1477,14 +1583,21 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
} else { /* dict not within tmp */
size_t const reservedDictSpace = MIN(dctx->dictSize, 64 KB);
dctx->tmpOut = dctx->tmpOutBuffer + reservedDictSpace;
- }
- }
+ } }
/* Decode block */
- { int const decodedSize = LZ4_decompress_safe_usingDict(
+ { const char* dict = (const char*)dctx->dict;
+ size_t dictSize = dctx->dictSize;
+ int decodedSize;
+ if (dict && dictSize > 1 GB) {
+ /* the dictSize param is an int, avoid truncation / sign issues */
+ dict += dictSize - 64 KB;
+ dictSize = 64 KB;
+ }
+ decodedSize = LZ4_decompress_safe_usingDict(
(const char*)selectedIn, (char*)dctx->tmpOut,
(int)dctx->tmpInTarget, (int)dctx->maxBlockSize,
- (const char*)dctx->dict, (int)dctx->dictSize);
+ dict, (int)dictSize);
if (decodedSize < 0) /* decompression failed */
return err0r(LZ4F_ERROR_decompressionFailed);
if (dctx->frameInfo.contentChecksumFlag)
@@ -1502,8 +1615,8 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
memcpy(dstPtr, dctx->tmpOut + dctx->tmpOutStart, sizeToCopy);
/* dictionary management */
- if (dctx->frameInfo.blockMode==LZ4F_blockLinked)
- LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1);
+ if (dctx->frameInfo.blockMode == LZ4F_blockLinked)
+ LZ4F_updateDict(dctx, dstPtr, sizeToCopy, dstStart, 1 /*withinTmp*/);
dctx->tmpOutStart += sizeToCopy;
dstPtr += sizeToCopy;
@@ -1512,35 +1625,34 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
dctx->dStage = dstage_getBlockHeader; /* get next block */
break;
}
+ /* could not flush everything : stop there, just request a block header */
+ doAnotherStage = 0;
nextSrcSizeHint = BHSize;
- doAnotherStage = 0; /* still some data to flush */
break;
}
case dstage_getSuffix:
- { size_t const suffixSize = dctx->frameInfo.contentChecksumFlag * 4;
- if (dctx->frameRemainingSize)
- return err0r(LZ4F_ERROR_frameSize_wrong); /* incorrect frame size decoded */
- if (suffixSize == 0) { /* frame completed */
- nextSrcSizeHint = 0;
- LZ4F_resetDecompressionContext(dctx);
- doAnotherStage = 0;
- break;
- }
- if ((srcEnd - srcPtr) < 4) { /* not enough size for entire CRC */
- dctx->tmpInSize = 0;
- dctx->dStage = dstage_storeSuffix;
- } else {
- selectedIn = srcPtr;
- srcPtr += 4;
- }
+ if (dctx->frameRemainingSize)
+ return err0r(LZ4F_ERROR_frameSize_wrong); /* incorrect frame size decoded */
+ if (!dctx->frameInfo.contentChecksumFlag) { /* no checksum, frame is completed */
+ nextSrcSizeHint = 0;
+ LZ4F_resetDecompressionContext(dctx);
+ doAnotherStage = 0;
+ break;
+ }
+ if ((srcEnd - srcPtr) < 4) { /* not enough size for entire CRC */
+ dctx->tmpInSize = 0;
+ dctx->dStage = dstage_storeSuffix;
+ } else {
+ selectedIn = srcPtr;
+ srcPtr += 4;
}
if (dctx->dStage == dstage_storeSuffix) /* can be skipped */
case dstage_storeSuffix:
- {
- size_t sizeToCopy = 4 - dctx->tmpInSize;
- if (sizeToCopy > (size_t)(srcEnd - srcPtr)) sizeToCopy = srcEnd - srcPtr;
+ { size_t const remainingInput = (size_t)(srcEnd - srcPtr);
+ size_t const wantedData = 4 - dctx->tmpInSize;
+ size_t const sizeToCopy = MIN(wantedData, remainingInput);
memcpy(dctx->tmpIn + dctx->tmpInSize, srcPtr, sizeToCopy);
srcPtr += sizeToCopy;
dctx->tmpInSize += sizeToCopy;
@@ -1550,9 +1662,9 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
break;
}
selectedIn = dctx->tmpIn;
- }
+ } /* if (dctx->dStage == dstage_storeSuffix) */
- /* case dstage_checkSuffix: */ /* no direct call, avoid scan-build warning */
+ /* case dstage_checkSuffix: */ /* no direct entry, avoid initialization risks */
{ U32 const readCRC = LZ4F_readLE32(selectedIn);
U32 const resultCRC = XXH32_digest(&(dctx->xxh));
if (readCRC != resultCRC)
@@ -1576,8 +1688,7 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
if (dctx->dStage == dstage_storeSFrameSize)
case dstage_storeSFrameSize:
- {
- size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize,
+ { size_t const sizeToCopy = MIN(dctx->tmpInTarget - dctx->tmpInSize,
(size_t)(srcEnd - srcPtr) );
memcpy(dctx->header + dctx->tmpInSize, srcPtr, sizeToCopy);
srcPtr += sizeToCopy;
@@ -1589,9 +1700,9 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
break;
}
selectedIn = dctx->header + 4;
- }
+ } /* if (dctx->dStage == dstage_storeSFrameSize) */
- /* case dstage_decodeSFrameSize: */ /* no direct access */
+ /* case dstage_decodeSFrameSize: */ /* no direct entry */
{ size_t const SFrameSize = LZ4F_readLE32(selectedIn);
dctx->frameInfo.contentSize = SFrameSize;
dctx->tmpInTarget = SFrameSize;
@@ -1606,36 +1717,38 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
doAnotherStage = 0;
nextSrcSizeHint = dctx->tmpInTarget;
if (nextSrcSizeHint) break; /* still more to skip */
+ /* frame fully skipped : prepare context for a new frame */
LZ4F_resetDecompressionContext(dctx);
break;
}
- }
- }
-
- /* preserve history within tmp if necessary */
- if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked)
- && (dctx->dict != dctx->tmpOutBuffer)
- && (dctx->dStage != dstage_getFrameHeader)
- && (!decompressOptionsPtr->stableDst)
- && ((unsigned)(dctx->dStage-1) < (unsigned)(dstage_getSuffix-1)) )
+ } /* switch (dctx->dStage) */
+ } /* while (doAnotherStage) */
+
+ /* preserve history within tmp whenever necessary */
+ LZ4F_STATIC_ASSERT((unsigned)dstage_init == 2);
+ if ( (dctx->frameInfo.blockMode==LZ4F_blockLinked) /* next block will use up to 64KB from previous ones */
+ && (dctx->dict != dctx->tmpOutBuffer) /* dictionary is not already within tmp */
+ && (!decompressOptionsPtr->stableDst) /* cannot rely on dst data to remain there for next call */
+ && ((unsigned)(dctx->dStage)-2 < (unsigned)(dstage_getSuffix)-2) ) /* valid stages : [init ... getSuffix[ */
{
if (dctx->dStage == dstage_flushOut) {
- size_t preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
+ size_t const preserveSize = dctx->tmpOut - dctx->tmpOutBuffer;
size_t copySize = 64 KB - dctx->tmpOutSize;
const BYTE* oldDictEnd = dctx->dict + dctx->dictSize - dctx->tmpOutStart;
if (dctx->tmpOutSize > 64 KB) copySize = 0;
if (copySize > preserveSize) copySize = preserveSize;
- memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
+ if (copySize > 0)
+ memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
dctx->dict = dctx->tmpOutBuffer;
dctx->dictSize = preserveSize + dctx->tmpOutStart;
} else {
- size_t newDictSize = dctx->dictSize;
- const BYTE* oldDictEnd = dctx->dict + dctx->dictSize;
- if ((newDictSize) > 64 KB) newDictSize = 64 KB;
+ const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize;
+ size_t const newDictSize = MIN(dctx->dictSize, 64 KB);
- memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
+ if (newDictSize > 0)
+ memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
dctx->dict = dctx->tmpOutBuffer;
dctx->dictSize = newDictSize;
diff --git a/lib/lz4frame.h b/lib/lz4frame.h
index 4dc67634a4d..98365388550 100644
--- a/lib/lz4frame.h
+++ b/lib/lz4frame.h
@@ -33,9 +33,10 @@
*/
/* LZ4F is a stand-alone API to create LZ4-compressed frames
- * conformant with specification v1.5.1.
+ * conformant with specification v1.6.1.
* It also offers streaming capabilities.
- * lz4.h is not required when using lz4frame.h.
+ * lz4.h is not required when using lz4frame.h,
+ * except to get constant such as LZ4_VERSION_NUMBER.
* */
#ifndef LZ4F_H_09782039843
@@ -95,8 +96,8 @@ extern "C" {
**************************************/
typedef size_t LZ4F_errorCode_t;
-LZ4FLIB_API unsigned LZ4F_isError(LZ4F_errorCode_t code); /**< tells if a `LZ4F_errorCode_t` function result is an error code */
-LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /**< return error code string; useful for debugging */
+LZ4FLIB_API unsigned LZ4F_isError(LZ4F_errorCode_t code); /**< tells when a function result is an error code */
+LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /**< return error code string; for debugging */
/*-************************************
@@ -161,38 +162,48 @@ typedef LZ4F_contentChecksum_t contentChecksum_t;
/*! LZ4F_frameInfo_t :
* makes it possible to set or read frame parameters.
- * It's not required to set all fields, as long as the structure was initially memset() to zero.
- * For all fields, 0 sets it to default value */
+ * Structure must be first init to 0, using memset() or LZ4F_INIT_FRAMEINFO,
+ * setting all parameters to default.
+ * It's then possible to update selectively some parameters */
typedef struct {
- LZ4F_blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB ; 0 == default */
- LZ4F_blockMode_t blockMode; /* LZ4F_blockLinked, LZ4F_blockIndependent ; 0 == default */
- LZ4F_contentChecksum_t contentChecksumFlag; /* if enabled, frame is terminated with a 32-bits checksum of decompressed data ; 0 == disabled (default) */
- LZ4F_frameType_t frameType; /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
- unsigned long long contentSize; /* Size of uncompressed content ; 0 == unknown */
- unsigned dictID; /* Dictionary ID, sent by the compressor to help decoder select the correct dictionary; 0 == no dictID provided */
- LZ4F_blockChecksum_t blockChecksumFlag; /* if enabled, each block is followed by a checksum of block's compressed data ; 0 == disabled (default) */
+ LZ4F_blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB; 0 == default */
+ LZ4F_blockMode_t blockMode; /* LZ4F_blockLinked, LZ4F_blockIndependent; 0 == default */
+ LZ4F_contentChecksum_t contentChecksumFlag; /* 1: frame terminated with 32-bit checksum of decompressed data; 0: disabled (default) */
+ LZ4F_frameType_t frameType; /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
+ unsigned long long contentSize; /* Size of uncompressed content ; 0 == unknown */
+ unsigned dictID; /* Dictionary ID, sent by compressor to help decoder select correct dictionary; 0 == no dictID provided */
+ LZ4F_blockChecksum_t blockChecksumFlag; /* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */
} LZ4F_frameInfo_t;
+#define LZ4F_INIT_FRAMEINFO { 0, 0, 0, 0, 0, 0, 0 } /* v1.8.3+ */
+
/*! LZ4F_preferences_t :
- * makes it possible to supply detailed compression parameters to the stream interface.
- * It's not required to set all fields, as long as the structure was initially memset() to zero.
+ * makes it possible to supply advanced compression instructions to streaming interface.
+ * Structure must be first init to 0, using memset() or LZ4F_INIT_PREFERENCES,
+ * setting all parameters to default.
* All reserved fields must be set to zero. */
typedef struct {
LZ4F_frameInfo_t frameInfo;
- int compressionLevel; /* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */
- unsigned autoFlush; /* 1 == always flush, to reduce usage of internal buffers */
- unsigned reserved[4]; /* must be zero for forward compatibility */
+ int compressionLevel; /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
+ unsigned autoFlush; /* 1: always flush; reduces usage of internal buffers */
+ unsigned favorDecSpeed; /* 1: parser favors decompression speed vs compression ratio. Only works for high compression modes (>= LZ4HC_CLEVEL_OPT_MIN) */ /* v1.8.2+ */
+ unsigned reserved[3]; /* must be zero for forward compatibility */
} LZ4F_preferences_t;
-LZ4FLIB_API int LZ4F_compressionLevel_max(void);
+#define LZ4F_INIT_PREFERENCES { LZ4F_INIT_FRAMEINFO, 0, 0, 0, { 0, 0, 0 } } /* v1.8.3+ */
/*-*********************************
* Simple compression function
***********************************/
+
+LZ4FLIB_API int LZ4F_compressionLevel_max(void);
+
/*! LZ4F_compressFrameBound() :
- * Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences.
- * Note : this result is only usable with LZ4F_compressFrame(), not with multi-segments compression.
+ * Returns the maximum possible compressed size with LZ4F_compressFrame() given srcSize and preferences.
+ * `preferencesPtr` is optional. It can be replaced by NULL, in which case, the function will assume default preferences.
+ * Note : this result is only usable with LZ4F_compressFrame().
+ * It may also be used with LZ4F_compressUpdate() _if no flush() operation_ is performed.
*/
LZ4FLIB_API size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
@@ -221,8 +232,9 @@ typedef struct {
/*--- Resource Management ---*/
-#define LZ4F_VERSION 100
+#define LZ4F_VERSION 100 /* This number can be used to check for an incompatible API breaking change */
LZ4FLIB_API unsigned LZ4F_getVersion(void);
+
/*! LZ4F_createCompressionContext() :
* The first thing to do is to create a compressionContext object, which will be used in all compression operations.
* This is achieved using LZ4F_createCompressionContext(), which takes as argument a version.
@@ -237,7 +249,7 @@ LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
/*---- Compression ----*/
-#define LZ4F_HEADER_SIZE_MAX 19
+#define LZ4F_HEADER_SIZE_MAX 19 /* LZ4 Frame header size can vary from 7 to 19 bytes */
/*! LZ4F_compressBegin() :
* will write the frame header into dstBuffer.
* dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
@@ -250,45 +262,58 @@ LZ4FLIB_API size_t LZ4F_compressBegin(LZ4F_cctx* cctx,
const LZ4F_preferences_t* prefsPtr);
/*! LZ4F_compressBound() :
- * Provides dstCapacity given a srcSize to guarantee operation success in worst case situations.
- * prefsPtr is optional : you can provide NULL as argument, preferences will be set to cover worst case scenario.
- * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
- * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
+ * Provides minimum dstCapacity required to guarantee compression success
+ * given a srcSize and preferences, covering worst case scenario.
+ * prefsPtr is optional : when NULL is provided, preferences will be set to cover worst case scenario.
+ * Estimation is valid for either LZ4F_compressUpdate(), LZ4F_flush() or LZ4F_compressEnd(),
+ * Estimation includes the possibility that internal buffer might already be filled by up to (blockSize-1) bytes.
+ * It also includes frame footer (ending + checksum), which would have to be generated by LZ4F_compressEnd().
+ * Estimation doesn't include frame header, as it was already generated by LZ4F_compressBegin().
+ * Result is always the same for a srcSize and prefsPtr, so it can be trusted to size reusable buffers.
+ * When srcSize==0, LZ4F_compressBound() provides an upper bound for LZ4F_flush() and LZ4F_compressEnd() operations.
*/
LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t* prefsPtr);
/*! LZ4F_compressUpdate() :
- * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
- * An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
- * This value is provided by LZ4F_compressBound().
- * If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
- * LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
+ * LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
+ * Important rule: dstCapacity MUST be large enough to ensure operation success even in worst case situations.
+ * This value is provided by LZ4F_compressBound().
+ * If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
+ * LZ4F_compressUpdate() doesn't guarantee error recovery.
+ * When an error occurs, compression context must be freed or resized.
* `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
* @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
* or an error code if it fails (which can be tested using LZ4F_isError())
*/
-LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
+LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx,
+ void* dstBuffer, size_t dstCapacity,
+ const void* srcBuffer, size_t srcSize,
+ const LZ4F_compressOptions_t* cOptPtr);
/*! LZ4F_flush() :
- * When data must be generated and sent immediately, without waiting for a block to be completely filled,
- * it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
+ * When data must be generated and sent immediately, without waiting for a block to be completely filled,
+ * it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
* `dstCapacity` must be large enough to ensure the operation will be successful.
* `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
- * @return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx)
+ * @return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx)
* or an error code if it fails (which can be tested using LZ4F_isError())
*/
-LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
+LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx,
+ void* dstBuffer, size_t dstCapacity,
+ const LZ4F_compressOptions_t* cOptPtr);
/*! LZ4F_compressEnd() :
* To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
* It will flush whatever data remained within `cctx` (like LZ4_flush())
* and properly finalize the frame, with an endMark and a checksum.
* `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
- * @return : number of bytes written into dstBuffer (necessarily >= 4 (endMark), or 8 if optional frame checksum is enabled)
+ * @return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark),
* or an error code if it fails (which can be tested using LZ4F_isError())
* A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
*/
-LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
+LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx,
+ void* dstBuffer, size_t dstCapacity,
+ const LZ4F_compressOptions_t* cOptPtr);
/*-*********************************
@@ -298,21 +323,21 @@ typedef struct LZ4F_dctx_s LZ4F_dctx; /* incomplete type */
typedef LZ4F_dctx* LZ4F_decompressionContext_t; /* compatibility with previous API versions */
typedef struct {
- unsigned stableDst; /* pledge that at least 64KB+64Bytes of previously decompressed data remain unmodifed where it was decoded. This optimization skips storage operations in tmp buffers */
+ unsigned stableDst; /* pledges that last 64KB decompressed data will remain available unmodified. This optimization skips storage operations in tmp buffers. */
unsigned reserved[3]; /* must be set to zero for forward compatibility */
} LZ4F_decompressOptions_t;
/* Resource management */
-/*!LZ4F_createDecompressionContext() :
- * Create an LZ4F_dctx object, to track all decompression operations.
- * The version provided MUST be LZ4F_VERSION.
- * The function provides a pointer to an allocated and initialized LZ4F_dctx object.
- * The result is an errorCode, which can be tested using LZ4F_isError().
- * dctx memory can be released using LZ4F_freeDecompressionContext();
- * The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
- * That is, it should be == 0 if decompression has been completed fully and correctly.
+/*! LZ4F_createDecompressionContext() :
+ * Create an LZ4F_dctx object, to track all decompression operations.
+ * The version provided MUST be LZ4F_VERSION.
+ * The function provides a pointer to an allocated and initialized LZ4F_dctx object.
+ * The result is an errorCode, which can be tested using LZ4F_isError().
+ * dctx memory can be released using LZ4F_freeDecompressionContext();
+ * Result of LZ4F_freeDecompressionContext() indicates current state of decompressionContext when being released.
+ * That is, it should be == 0 if decompression has been completed fully and correctly.
*/
LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
LZ4FLIB_API LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
@@ -349,27 +374,32 @@ LZ4FLIB_API size_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
/*! LZ4F_decompress() :
* Call this function repetitively to regenerate compressed data from `srcBuffer`.
- * The function will attempt to decode up to *srcSizePtr bytes from srcBuffer, into dstBuffer of capacity *dstSizePtr.
+ * The function will read up to *srcSizePtr bytes from srcBuffer,
+ * and decompress data into dstBuffer, of capacity *dstSizePtr.
*
- * The number of bytes regenerated into dstBuffer is provided within *dstSizePtr (necessarily <= original value).
+ * The nb of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
+ * The nb of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
*
- * The number of bytes consumed from srcBuffer is provided within *srcSizePtr (necessarily <= original value).
- * Number of bytes consumed can be < number of bytes provided.
- * It typically happens when dstBuffer is not large enough to contain all decoded data.
+ * The function does not necessarily read all input bytes, so always check value in *srcSizePtr.
* Unconsumed source data must be presented again in subsequent invocations.
*
- * `dstBuffer` content is expected to be flushed between each invocation, as its content will be overwritten.
- * `dstBuffer` itself can be changed at will between each consecutive function invocation.
+ * `dstBuffer` can freely change between each consecutive function invocation.
+ * `dstBuffer` content will be overwritten.
*
* @return : an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
* Schematically, it's the size of the current (or remaining) compressed block + header of next block.
* Respecting the hint provides some small speed benefit, because it skips intermediate buffers.
* This is just a hint though, it's always possible to provide any srcSize.
+ *
* When a frame is fully decoded, @return will be 0 (no more data expected).
+ * When provided with more bytes than necessary to decode a frame,
+ * LZ4F_decompress() will stop reading exactly at end of current frame, and @return 0.
+ *
* If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
+ * After a decompression error, the `dctx` context is not resumable.
+ * Use LZ4F_resetDecompressionContext() to return to clean state.
*
* After a frame is fully decoded, dctx can be used again to decompress another frame.
- * After a decompression error, use LZ4F_resetDecompressionContext() before re-using dctx, to return to clean state.
*/
LZ4FLIB_API size_t LZ4F_decompress(LZ4F_dctx* dctx,
void* dstBuffer, size_t* dstSizePtr,
@@ -377,11 +407,11 @@ LZ4FLIB_API size_t LZ4F_decompress(LZ4F_dctx* dctx,
const LZ4F_decompressOptions_t* dOptPtr);
-/*! LZ4F_resetDecompressionContext() : v1.8.0
+/*! LZ4F_resetDecompressionContext() : added in v1.8.0
* In case of an error, the context is left in "undefined" state.
* In which case, it's necessary to reset it, before re-using it.
- * This method can also be used to abruptly stop an unfinished decompression,
- * and start a new one using the same context. */
+ * This method can also be used to abruptly stop any unfinished decompression,
+ * and start a new one using same context resources. */
LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx); /* always successful */
@@ -391,3 +421,123 @@ LZ4FLIB_API void LZ4F_resetDecompressionContext(LZ4F_dctx* dctx); /* always su
#endif
#endif /* LZ4F_H_09782039843 */
+
+#if defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843)
+#define LZ4F_H_STATIC_09782039843
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/* These declarations are not stable and may change in the future. They are
+ * therefore only safe to depend on when the caller is statically linked
+ * against the library. To access their declarations, define
+ * LZ4F_STATIC_LINKING_ONLY.
+ *
+ * There is a further protection mechanism where these symbols aren't published
+ * into shared/dynamic libraries. You can override this behavior and force
+ * them to be published by defining LZ4F_PUBLISH_STATIC_FUNCTIONS. Use at
+ * your own risk.
+ */
+#ifdef LZ4F_PUBLISH_STATIC_FUNCTIONS
+#define LZ4FLIB_STATIC_API LZ4FLIB_API
+#else
+#define LZ4FLIB_STATIC_API
+#endif
+
+
+/* --- Error List --- */
+#define LZ4F_LIST_ERRORS(ITEM) \
+ ITEM(OK_NoError) \
+ ITEM(ERROR_GENERIC) \
+ ITEM(ERROR_maxBlockSize_invalid) \
+ ITEM(ERROR_blockMode_invalid) \
+ ITEM(ERROR_contentChecksumFlag_invalid) \
+ ITEM(ERROR_compressionLevel_invalid) \
+ ITEM(ERROR_headerVersion_wrong) \
+ ITEM(ERROR_blockChecksum_invalid) \
+ ITEM(ERROR_reservedFlag_set) \
+ ITEM(ERROR_allocation_failed) \
+ ITEM(ERROR_srcSize_tooLarge) \
+ ITEM(ERROR_dstMaxSize_tooSmall) \
+ ITEM(ERROR_frameHeader_incomplete) \
+ ITEM(ERROR_frameType_unknown) \
+ ITEM(ERROR_frameSize_wrong) \
+ ITEM(ERROR_srcPtr_wrong) \
+ ITEM(ERROR_decompressionFailed) \
+ ITEM(ERROR_headerChecksum_invalid) \
+ ITEM(ERROR_contentChecksum_invalid) \
+ ITEM(ERROR_frameDecoding_alreadyStarted) \
+ ITEM(ERROR_maxCode)
+
+#define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
+
+/* enum list is exposed, to handle specific errors */
+typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;
+
+LZ4FLIB_STATIC_API LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
+
+
+
+/**********************************
+ * Bulk processing dictionary API
+ *********************************/
+typedef struct LZ4F_CDict_s LZ4F_CDict;
+
+/*! LZ4_createCDict() :
+ * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+ * LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+ * LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
+LZ4FLIB_STATIC_API LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
+LZ4FLIB_STATIC_API void LZ4F_freeCDict(LZ4F_CDict* CDict);
+
+
+/*! LZ4_compressFrame_usingCDict() :
+ * Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
+ * cctx must point to a context created by LZ4F_createCompressionContext().
+ * If cdict==NULL, compress without a dictionary.
+ * dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
+ * If this condition is not respected, function will fail (@return an errorCode).
+ * The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
+ * but it's not recommended, as it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer.
+ * or an error code if it fails (can be tested using LZ4F_isError()) */
+LZ4FLIB_STATIC_API size_t LZ4F_compressFrame_usingCDict(
+ LZ4F_cctx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const LZ4F_CDict* cdict,
+ const LZ4F_preferences_t* preferencesPtr);
+
+
+/*! LZ4F_compressBegin_usingCDict() :
+ * Inits streaming dictionary compression, and writes the frame header into dstBuffer.
+ * dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
+ * `prefsPtr` is optional : you may provide NULL as argument,
+ * however, it's the only way to provide dictID in the frame header.
+ * @return : number of bytes written into dstBuffer for the header,
+ * or an error code (which can be tested using LZ4F_isError()) */
+LZ4FLIB_STATIC_API size_t LZ4F_compressBegin_usingCDict(
+ LZ4F_cctx* cctx,
+ void* dstBuffer, size_t dstCapacity,
+ const LZ4F_CDict* cdict,
+ const LZ4F_preferences_t* prefsPtr);
+
+
+/*! LZ4F_decompress_usingDict() :
+ * Same as LZ4F_decompress(), using a predefined dictionary.
+ * Dictionary is used "in place", without any preprocessing.
+ * It must remain accessible throughout the entire frame decoding. */
+LZ4FLIB_STATIC_API size_t LZ4F_decompress_usingDict(
+ LZ4F_dctx* dctxPtr,
+ void* dstBuffer, size_t* dstSizePtr,
+ const void* srcBuffer, size_t* srcSizePtr,
+ const void* dict, size_t dictSize,
+ const LZ4F_decompressOptions_t* decompressOptionsPtr);
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* defined(LZ4F_STATIC_LINKING_ONLY) && !defined(LZ4F_H_STATIC_09782039843) */
diff --git a/lib/lz4frame_static.h b/lib/lz4frame_static.h
index 1899f8e4662..925a2c5c330 100644
--- a/lib/lz4frame_static.h
+++ b/lib/lz4frame_static.h
@@ -36,108 +36,12 @@
#ifndef LZ4FRAME_STATIC_H_0398209384
#define LZ4FRAME_STATIC_H_0398209384
-#if defined (__cplusplus)
-extern "C" {
-#endif
-
-/* lz4frame_static.h should be used solely in the context of static linking.
- * It contains definitions which are not stable and may change in the future.
- * Never use it in the context of DLL linking.
+/* The declarations that formerly were made here have been merged into
+ * lz4frame.h, protected by the LZ4F_STATIC_LINKING_ONLY macro. Going forward,
+ * it is recommended to simply include that header directly.
*/
-
-/* --- Dependency --- */
+#define LZ4F_STATIC_LINKING_ONLY
#include "lz4frame.h"
-
-/* --- Error List --- */
-#define LZ4F_LIST_ERRORS(ITEM) \
- ITEM(OK_NoError) \
- ITEM(ERROR_GENERIC) \
- ITEM(ERROR_maxBlockSize_invalid) \
- ITEM(ERROR_blockMode_invalid) \
- ITEM(ERROR_contentChecksumFlag_invalid) \
- ITEM(ERROR_compressionLevel_invalid) \
- ITEM(ERROR_headerVersion_wrong) \
- ITEM(ERROR_blockChecksum_invalid) \
- ITEM(ERROR_reservedFlag_set) \
- ITEM(ERROR_allocation_failed) \
- ITEM(ERROR_srcSize_tooLarge) \
- ITEM(ERROR_dstMaxSize_tooSmall) \
- ITEM(ERROR_frameHeader_incomplete) \
- ITEM(ERROR_frameType_unknown) \
- ITEM(ERROR_frameSize_wrong) \
- ITEM(ERROR_srcPtr_wrong) \
- ITEM(ERROR_decompressionFailed) \
- ITEM(ERROR_headerChecksum_invalid) \
- ITEM(ERROR_contentChecksum_invalid) \
- ITEM(ERROR_frameDecoding_alreadyStarted) \
- ITEM(ERROR_maxCode)
-
-#define LZ4F_GENERATE_ENUM(ENUM) LZ4F_##ENUM,
-
-/* enum list is exposed, to handle specific errors */
-typedef enum { LZ4F_LIST_ERRORS(LZ4F_GENERATE_ENUM) } LZ4F_errorCodes;
-
-LZ4F_errorCodes LZ4F_getErrorCode(size_t functionResult);
-
-
-
-/**********************************
- * Bulk processing dictionary API
- *********************************/
-typedef struct LZ4F_CDict_s LZ4F_CDict;
-
-/*! LZ4_createCDict() :
- * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
- * LZ4_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
- * LZ4_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
- * `dictBuffer` can be released after LZ4_CDict creation, since its content is copied within CDict */
-LZ4F_CDict* LZ4F_createCDict(const void* dictBuffer, size_t dictSize);
-void LZ4F_freeCDict(LZ4F_CDict* CDict);
-
-
-/*! LZ4_compressFrame_usingCDict() :
- * Compress an entire srcBuffer into a valid LZ4 frame using a digested Dictionary.
- * If cdict==NULL, compress without a dictionary.
- * dstBuffer MUST be >= LZ4F_compressFrameBound(srcSize, preferencesPtr).
- * If this condition is not respected, function will fail (@return an errorCode).
- * The LZ4F_preferences_t structure is optional : you may provide NULL as argument,
- * but it's not recommended, as it's the only way to provide dictID in the frame header.
- * @return : number of bytes written into dstBuffer.
- * or an error code if it fails (can be tested using LZ4F_isError()) */
-size_t LZ4F_compressFrame_usingCDict(void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const LZ4F_CDict* cdict,
- const LZ4F_preferences_t* preferencesPtr);
-
-
-/*! LZ4F_compressBegin_usingCDict() :
- * Inits streaming dictionary compression, and writes the frame header into dstBuffer.
- * dstCapacity must be >= LZ4F_HEADER_SIZE_MAX bytes.
- * `prefsPtr` is optional : you may provide NULL as argument,
- * however, it's the only way to provide dictID in the frame header.
- * @return : number of bytes written into dstBuffer for the header,
- * or an error code (which can be tested using LZ4F_isError()) */
-size_t LZ4F_compressBegin_usingCDict(LZ4F_cctx* cctx,
- void* dstBuffer, size_t dstCapacity,
- const LZ4F_CDict* cdict,
- const LZ4F_preferences_t* prefsPtr);
-
-
-/*! LZ4F_decompress_usingDict() :
- * Same as LZ4F_decompress(), using a predefined dictionary.
- * Dictionary is used "in place", without any preprocessing.
- * It must remain accessible throughout the entire frame decoding. */
-size_t LZ4F_decompress_usingDict(LZ4F_dctx* dctxPtr,
- void* dstBuffer, size_t* dstSizePtr,
- const void* srcBuffer, size_t* srcSizePtr,
- const void* dict, size_t dictSize,
- const LZ4F_decompressOptions_t* decompressOptionsPtr);
-
-
-#if defined (__cplusplus)
-}
-#endif
-
#endif /* LZ4FRAME_STATIC_H_0398209384 */
diff --git a/lib/lz4hc.c b/lib/lz4hc.c
index 22eb071e9ce..e913ee7b323 100644
--- a/lib/lz4hc.c
+++ b/lib/lz4hc.c
@@ -49,6 +49,7 @@
/*=== Dependency ===*/
+#define LZ4_HC_STATIC_LINKING_ONLY
#include "lz4hc.h"
@@ -66,6 +67,7 @@
/*=== Constants ===*/
#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
+#define LZ4_OPT_NUM (1<<12)
/*=== Macros ===*/
@@ -77,26 +79,38 @@
static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
+/*=== Enums ===*/
+typedef enum { noDictCtx, usingDictCtx } dictCtx_directive;
/**************************************
* HC Compression
**************************************/
-static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start)
+static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
{
MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable));
MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
- hc4->nextToUpdate = 64 KB;
- hc4->base = start - 64 KB;
+}
+
+static void LZ4HC_init (LZ4HC_CCtx_internal* hc4, const BYTE* start)
+{
+ uptrval startingOffset = hc4->end - hc4->base;
+ if (startingOffset > 1 GB) {
+ LZ4HC_clearTables(hc4);
+ startingOffset = 0;
+ }
+ startingOffset += 64 KB;
+ hc4->nextToUpdate = (U32) startingOffset;
+ hc4->base = start - startingOffset;
hc4->end = start;
- hc4->dictBase = start - 64 KB;
- hc4->dictLimit = 64 KB;
- hc4->lowLimit = 64 KB;
+ hc4->dictBase = start - startingOffset;
+ hc4->dictLimit = (U32) startingOffset;
+ hc4->lowLimit = (U32) startingOffset;
}
/* Update chains up to ip (excluded) */
-FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
+LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
{
U16* const chainTable = hc4->chainTable;
U32* const hashTable = hc4->hashTable;
@@ -116,56 +130,80 @@ FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
hc4->nextToUpdate = target;
}
-
-FORCE_INLINE int LZ4HC_InsertAndFindBestMatch (LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */
- const BYTE* const ip, const BYTE* const iLimit,
- const BYTE** matchpos,
- const int maxNbAttempts)
+/** LZ4HC_countBack() :
+ * @return : negative value, nb of common bytes before ip/match */
+LZ4_FORCE_INLINE
+int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match,
+ const BYTE* const iMin, const BYTE* const mMin)
{
- U16* const chainTable = hc4->chainTable;
- U32* const HashTable = hc4->hashTable;
- const BYTE* const base = hc4->base;
- const BYTE* const dictBase = hc4->dictBase;
- const U32 dictLimit = hc4->dictLimit;
- const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
- U32 matchIndex;
- int nbAttempts = maxNbAttempts;
- size_t ml = 0;
+ int back = 0;
+ int const min = (int)MAX(iMin - ip, mMin - match);
+ assert(min <= 0);
+ assert(ip >= iMin); assert((size_t)(ip-iMin) < (1U<<31));
+ assert(match >= mMin); assert((size_t)(match - mMin) < (1U<<31));
+ while ( (back > min)
+ && (ip[back-1] == match[back-1]) )
+ back--;
+ return back;
+}
- /* HC4 match finder */
- LZ4HC_Insert(hc4, ip);
- matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+/* LZ4HC_countPattern() :
+ * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */
+static unsigned
+LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32)
+{
+ const BYTE* const iStart = ip;
+ reg_t const pattern = (sizeof(pattern)==8) ? (reg_t)pattern32 + (((reg_t)pattern32) << 32) : pattern32;
+
+ while (likely(ip < iEnd-(sizeof(pattern)-1))) {
+ reg_t const diff = LZ4_read_ARCH(ip) ^ pattern;
+ if (!diff) { ip+=sizeof(pattern); continue; }
+ ip += LZ4_NbCommonBytes(diff);
+ return (unsigned)(ip - iStart);
+ }
- while ((matchIndex>=lowLimit) && (nbAttempts)) {
- nbAttempts--;
- if (matchIndex >= dictLimit) {
- const BYTE* const match = base + matchIndex;
- if ( (*(match+ml) == *(ip+ml)) /* can be longer */
- && (LZ4_read32(match) == LZ4_read32(ip)) )
- {
- size_t const mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, iLimit) + MINMATCH;
- if (mlt > ml) { ml = mlt; *matchpos = match; }
- }
- } else {
- const BYTE* const match = dictBase + matchIndex;
- if (LZ4_read32(match) == LZ4_read32(ip)) {
- size_t mlt;
- const BYTE* vLimit = ip + (dictLimit - matchIndex);
- if (vLimit > iLimit) vLimit = iLimit;
- mlt = LZ4_count(ip+MINMATCH, match+MINMATCH, vLimit) + MINMATCH;
- if ((ip+mlt == vLimit) && (vLimit < iLimit))
- mlt += LZ4_count(ip+mlt, base+dictLimit, iLimit);
- if (mlt > ml) { ml = mlt; *matchpos = base + matchIndex; } /* virtual matchpos */
- }
+ if (LZ4_isLittleEndian()) {
+ reg_t patternByte = pattern;
+ while ((ip<iEnd) && (*ip == (BYTE)patternByte)) {
+ ip++; patternByte >>= 8;
+ }
+ } else { /* big endian */
+ U32 bitOffset = (sizeof(pattern)*8) - 8;
+ while (ip < iEnd) {
+ BYTE const byte = (BYTE)(pattern >> bitOffset);
+ if (*ip != byte) break;
+ ip ++; bitOffset -= 8;
}
- matchIndex -= DELTANEXTU16(chainTable, matchIndex);
}
- return (int)ml;
+ return (unsigned)(ip - iStart);
+}
+
+/* LZ4HC_reverseCountPattern() :
+ * pattern must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!)
+ * read using natural platform endianess */
+static unsigned
+LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern)
+{
+ const BYTE* const iStart = ip;
+
+ while (likely(ip >= iLow+4)) {
+ if (LZ4_read32(ip-4) != pattern) break;
+ ip -= 4;
+ }
+ { const BYTE* bytePtr = (const BYTE*)(&pattern) + 3; /* works for any endianess */
+ while (likely(ip>iLow)) {
+ if (ip[-1] != *bytePtr) break;
+ ip--; bytePtr--;
+ } }
+ return (unsigned)(iStart - ip);
}
+typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e;
+typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e;
-FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
+LZ4_FORCE_INLINE int
+LZ4HC_InsertAndGetWiderMatch (
LZ4HC_CCtx_internal* hc4,
const BYTE* const ip,
const BYTE* const iLowLimit,
@@ -173,67 +211,191 @@ FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch (
int longest,
const BYTE** matchpos,
const BYTE** startpos,
- const int maxNbAttempts)
+ const int maxNbAttempts,
+ const int patternAnalysis,
+ const int chainSwap,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
{
U16* const chainTable = hc4->chainTable;
U32* const HashTable = hc4->hashTable;
+ const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx;
const BYTE* const base = hc4->base;
const U32 dictLimit = hc4->dictLimit;
const BYTE* const lowPrefixPtr = base + dictLimit;
- const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - (64 KB - 1);
+ const U32 ipIndex = (U32)(ip - base);
+ const U32 lowestMatchIndex = (hc4->lowLimit + 64 KB > ipIndex) ? hc4->lowLimit : ipIndex - MAX_DISTANCE;
const BYTE* const dictBase = hc4->dictBase;
- int const delta = (int)(ip-iLowLimit);
+ int const lookBackLength = (int)(ip-iLowLimit);
int nbAttempts = maxNbAttempts;
+ int matchChainPos = 0;
+ U32 const pattern = LZ4_read32(ip);
U32 matchIndex;
+ U32 dictMatchIndex;
+ repeat_state_e repeat = rep_untested;
+ size_t srcPatternLength = 0;
-
+ DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch");
/* First Match */
LZ4HC_Insert(hc4, ip);
matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+ DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)",
+ matchIndex, lowestMatchIndex);
- while ((matchIndex>=lowLimit) && (nbAttempts)) {
+ while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) {
+ int matchLength=0;
nbAttempts--;
- if (matchIndex >= dictLimit) {
+ assert(matchIndex < ipIndex);
+ if (favorDecSpeed && (ipIndex - matchIndex < 8)) {
+ /* do nothing */
+ } else if (matchIndex >= dictLimit) { /* within current Prefix */
const BYTE* const matchPtr = base + matchIndex;
- if (*(iLowLimit + longest) == *(matchPtr - delta + longest)) {
- if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
- int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
- int back = 0;
-
- while ( (ip+back > iLowLimit)
- && (matchPtr+back > lowPrefixPtr)
- && (ip[back-1] == matchPtr[back-1])) {
- back--;
- }
-
- mlt -= back;
-
- if (mlt > longest) {
- longest = mlt;
- *matchpos = matchPtr+back;
- *startpos = ip+back;
+ assert(matchPtr >= lowPrefixPtr);
+ assert(matchPtr < ip);
+ assert(longest >= 1);
+ if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) {
+ if (LZ4_read32(matchPtr) == pattern) {
+ int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0;
+ matchLength = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
+ matchLength -= back;
+ if (matchLength > longest) {
+ longest = matchLength;
+ *matchpos = matchPtr + back;
+ *startpos = ip + back;
} } }
- } else {
+ } else { /* lowestMatchIndex <= matchIndex < dictLimit */
const BYTE* const matchPtr = dictBase + matchIndex;
- if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
- int mlt;
- int back=0;
+ if (LZ4_read32(matchPtr) == pattern) {
+ const BYTE* const dictStart = dictBase + hc4->lowLimit;
+ int back = 0;
const BYTE* vLimit = ip + (dictLimit - matchIndex);
if (vLimit > iHighLimit) vLimit = iHighLimit;
+ matchLength = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
+ if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
+ matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit);
+ back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0;
+ matchLength -= back;
+ if (matchLength > longest) {
+ longest = matchLength;
+ *matchpos = base + matchIndex + back; /* virtual pos, relative to ip, to retrieve offset */
+ *startpos = ip + back;
+ } } }
+
+ if (chainSwap && matchLength==longest) { /* better match => select a better chain */
+ assert(lookBackLength==0); /* search forward only */
+ if (matchIndex + longest <= ipIndex) {
+ U32 distanceToNextMatch = 1;
+ int pos;
+ for (pos = 0; pos <= longest - MINMATCH; pos++) {
+ U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + pos);
+ if (candidateDist > distanceToNextMatch) {
+ distanceToNextMatch = candidateDist;
+ matchChainPos = pos;
+ } }
+ if (distanceToNextMatch > 1) {
+ if (distanceToNextMatch > matchIndex) break; /* avoid overflow */
+ matchIndex -= distanceToNextMatch;
+ continue;
+ } } }
+
+ { U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex);
+ if (patternAnalysis && distNextMatch==1 && matchChainPos==0) {
+ U32 const matchCandidateIdx = matchIndex-1;
+ /* may be a repeated pattern */
+ if (repeat == rep_untested) {
+ if ( ((pattern & 0xFFFF) == (pattern >> 16))
+ & ((pattern & 0xFF) == (pattern >> 24)) ) {
+ repeat = rep_confirmed;
+ srcPatternLength = LZ4HC_countPattern(ip+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
+ } else {
+ repeat = rep_not;
+ } }
+ if ( (repeat == rep_confirmed)
+ && (matchCandidateIdx >= dictLimit) ) { /* same segment only */
+ const BYTE* const matchPtr = base + matchCandidateIdx;
+ if (LZ4_read32(matchPtr) == pattern) { /* good candidate */
+ size_t const forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
+ const BYTE* const lowestMatchPtr = (lowPrefixPtr + MAX_DISTANCE >= ip) ? lowPrefixPtr : ip - MAX_DISTANCE;
+ size_t const backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern);
+ size_t const currentSegmentLength = backLength + forwardPatternLength;
+
+ if ( (currentSegmentLength >= srcPatternLength) /* current pattern segment large enough to contain full srcPatternLength */
+ && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
+ matchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength; /* best position, full pattern, might be followed by more match */
+ } else {
+ matchIndex = matchCandidateIdx - (U32)backLength; /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */
+ if (lookBackLength==0) { /* no back possible */
+ size_t const maxML = MIN(currentSegmentLength, srcPatternLength);
+ if ((size_t)longest < maxML) {
+ assert(base + matchIndex < ip);
+ if (ip - (base+matchIndex) > MAX_DISTANCE) break;
+ assert(maxML < 2 GB);
+ longest = (int)maxML;
+ *matchpos = base + matchIndex; /* virtual pos, relative to ip, to retrieve offset */
+ *startpos = ip;
+ }
+ { U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex);
+ if (distToNextPattern > matchIndex) break; /* avoid overflow */
+ matchIndex -= distToNextPattern;
+ } } }
+ continue;
+ } }
+ } } /* PA optimization */
+
+ /* follow current chain */
+ matchIndex -= DELTANEXTU16(chainTable, matchIndex+matchChainPos);
+
+ } /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
+
+ if (dict == usingDictCtx && nbAttempts && ipIndex - lowestMatchIndex < MAX_DISTANCE) {
+ size_t const dictEndOffset = dictCtx->end - dictCtx->base;
+ assert(dictEndOffset <= 1 GB);
+ dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)];
+ matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset;
+ while (ipIndex - matchIndex <= MAX_DISTANCE && nbAttempts--) {
+ const BYTE* const matchPtr = dictCtx->base + dictMatchIndex;
+
+ if (LZ4_read32(matchPtr) == pattern) {
+ int mlt;
+ int back = 0;
+ const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex);
+ if (vLimit > iHighLimit) vLimit = iHighLimit;
mlt = LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
- if ((ip+mlt == vLimit) && (vLimit < iHighLimit))
- mlt += LZ4_count(ip+mlt, base+dictLimit, iHighLimit);
- while ((ip+back > iLowLimit) && (matchIndex+back > lowLimit) && (ip[back-1] == matchPtr[back-1])) back--;
+ back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0;
mlt -= back;
- if (mlt > longest) { longest = mlt; *matchpos = base + matchIndex + back; *startpos = ip+back; }
+ if (mlt > longest) {
+ longest = mlt;
+ *matchpos = base + matchIndex + back;
+ *startpos = ip + back;
+ }
+ }
+
+ { U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex);
+ dictMatchIndex -= nextOffset;
+ matchIndex -= nextOffset;
}
}
- matchIndex -= DELTANEXTU16(chainTable, matchIndex);
}
return longest;
}
+LZ4_FORCE_INLINE
+int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4, /* Index table will be updated */
+ const BYTE* const ip, const BYTE* const iLimit,
+ const BYTE** matchpos,
+ const int maxNbAttempts,
+ const int patternAnalysis,
+ const dictCtx_directive dict)
+{
+ const BYTE* uselessPtr = ip;
+ /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
+ * but this won't be the case here, as we define iLowLimit==ip,
+ * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
+ return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio);
+}
+
+
typedef enum {
noLimit = 0,
@@ -241,14 +403,10 @@ typedef enum {
limitedDestSize = 2,
} limitedOutput_directive;
-#ifndef LZ4HC_DEBUG
-# define LZ4HC_DEBUG 0
-#endif
-
/* LZ4HC_encodeSequence() :
* @return : 0 if ok,
* 1 if buffer issue detected */
-FORCE_INLINE int LZ4HC_encodeSequence (
+LZ4_FORCE_INLINE int LZ4HC_encodeSequence (
const BYTE** ip,
BYTE** op,
const BYTE** anchor,
@@ -260,9 +418,21 @@ FORCE_INLINE int LZ4HC_encodeSequence (
size_t length;
BYTE* const token = (*op)++;
-#if LZ4HC_DEBUG
- printf("literal : %u -- match : %u -- offset : %u\n",
- (U32)(*ip - *anchor), (U32)matchLength, (U32)(*ip-match));
+#if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6)
+ static const BYTE* start = NULL;
+ static U32 totalCost = 0;
+ U32 const pos = (start==NULL) ? 0 : (U32)(*anchor - start);
+ U32 const ll = (U32)(*ip - *anchor);
+ U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0;
+ U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0;
+ U32 const cost = 1 + llAdd + ll + 2 + mlAdd;
+ if (start==NULL) start = *anchor; /* only works for single segment */
+ /* g_debuglog_enable = (pos >= 2228) & (pos <= 2262); */
+ DEBUGLOG(6, "pos:%7u -- literals:%3u, match:%4i, offset:%5u, cost:%3u + %u",
+ pos,
+ (U32)(*ip - *anchor), matchLength, (U32)(*ip-match),
+ cost, totalCost);
+ totalCost += cost;
#endif
/* Encode Literal length */
@@ -282,9 +452,11 @@ FORCE_INLINE int LZ4HC_encodeSequence (
*op += length;
/* Encode Offset */
+ assert( (*ip - match) <= MAX_DISTANCE ); /* note : consider providing offset as a value, rather than as a pointer difference */
LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2;
/* Encode MatchLength */
+ assert(matchLength >= MINMATCH);
length = (size_t)(matchLength - MINMATCH);
if ((limit) && (*op + (length >> 8) + (1 + LASTLITERALS) > oend)) return 1; /* Check output limit */
if (length >= ML_MASK) {
@@ -304,21 +476,19 @@ FORCE_INLINE int LZ4HC_encodeSequence (
return 0;
}
-/* btopt */
-#include "lz4opt.h"
-
-
-static int LZ4HC_compress_hashChain (
+LZ4_FORCE_INLINE int LZ4HC_compress_hashChain (
LZ4HC_CCtx_internal* const ctx,
const char* const source,
char* const dest,
int* srcSizePtr,
int const maxOutputSize,
unsigned maxNbAttempts,
- limitedOutput_directive limit
+ const limitedOutput_directive limit,
+ const dictCtx_directive dict
)
{
const int inputSize = *srcSizePtr;
+ const int patternAnalysis = (maxNbAttempts > 128); /* levels 9+ */
const BYTE* ip = (const BYTE*) source;
const BYTE* anchor = ip;
@@ -330,55 +500,47 @@ static int LZ4HC_compress_hashChain (
BYTE* op = (BYTE*) dest;
BYTE* oend = op + maxOutputSize;
- int ml, ml2, ml3, ml0;
+ int ml0, ml, ml2, ml3;
+ const BYTE* start0;
+ const BYTE* ref0;
const BYTE* ref = NULL;
const BYTE* start2 = NULL;
const BYTE* ref2 = NULL;
const BYTE* start3 = NULL;
const BYTE* ref3 = NULL;
- const BYTE* start0;
- const BYTE* ref0;
/* init */
*srcSizePtr = 0;
- if (limit == limitedDestSize && maxOutputSize < 1) return 0; /* Impossible to store anything */
- if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */
-
- ctx->end += inputSize;
- if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support limitations LZ4 decompressor */
+ if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
- ip++;
-
/* Main Loop */
- while (ip < mflimit) {
- ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref), maxNbAttempts);
- if (!ml) { ip++; continue; }
+ while (ip <= mflimit) {
+ ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
+ if (ml<MINMATCH) { ip++; continue; }
/* saved, in case we would skip too much */
- start0 = ip;
- ref0 = ref;
- ml0 = ml;
+ start0 = ip; ref0 = ref; ml0 = ml;
_Search2:
- if (ip+ml < mflimit)
- ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2, maxNbAttempts);
- else
+ if (ip+ml <= mflimit) {
+ ml2 = LZ4HC_InsertAndGetWiderMatch(ctx,
+ ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2,
+ maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
+ } else {
ml2 = ml;
+ }
- if (ml2 == ml) { /* No better match */
+ if (ml2 == ml) { /* No better match => encode ML1 */
optr = op;
if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
continue;
}
- if (start0 < ip) {
- if (start2 < ip + ml0) { /* empirical */
- ip = start0;
- ref = ref0;
- ml = ml0;
- }
- }
+ if (start0 < ip) { /* first match was skipped at least once */
+ if (start2 < ip + ml0) { /* squeezing ML1 between ML0(original ML1) and ML2 */
+ ip = start0; ref = ref0; ml = ml0; /* restore initial ML1 */
+ } }
/* Here, start0==ip */
if ((start2 - ip) < 3) { /* First Match too small : removed */
@@ -406,12 +568,15 @@ _Search3:
}
/* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */
- if (start2 + ml2 < mflimit)
- ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3, maxNbAttempts);
- else
+ if (start2 + ml2 <= mflimit) {
+ ml3 = LZ4HC_InsertAndGetWiderMatch(ctx,
+ start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3,
+ maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
+ } else {
ml3 = ml2;
+ }
- if (ml3 == ml2) { /* No better match : 2 sequences to encode */
+ if (ml3 == ml2) { /* No better match => encode ML1 and ML2 */
/* ip & ref are known; Now for ml */
if (start2 < ip+ml) ml = (int)(start2 - ip);
/* Now, encode 2 sequences */
@@ -456,11 +621,12 @@ _Search3:
}
/*
- * OK, now we have 3 ascending matches; let's write at least the first one
- * ip & ref are known; Now for ml
+ * OK, now we have 3 ascending matches;
+ * let's write the first one ML1.
+ * ip & ref are known; Now decide ml.
*/
if (start2 < ip+ml) {
- if ((start2 - ip) < (int)ML_MASK) {
+ if ((start2 - ip) < OPTIMAL_ML) {
int correction;
if (ml > OPTIMAL_ML) ml = OPTIMAL_ML;
if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
@@ -477,14 +643,13 @@ _Search3:
optr = op;
if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow;
- ip = start2;
- ref = ref2;
- ml = ml2;
+ /* ML2 becomes ML1 */
+ ip = start2; ref = ref2; ml = ml2;
- start2 = start3;
- ref2 = ref3;
- ml2 = ml3;
+ /* ML3 becomes ML2 */
+ start2 = start3; ref2 = ref3; ml2 = ml3;
+ /* let's find a new ML3 */
goto _Search3;
}
@@ -527,12 +692,110 @@ _dest_overflow:
return 0;
}
-static int LZ4HC_getSearchNum(int compressionLevel)
+
+static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx,
+ const char* const source, char* dst,
+ int* srcSizePtr, int dstCapacity,
+ int const nbSearches, size_t sufficient_len,
+ const limitedOutput_directive limit, int const fullUpdate,
+ const dictCtx_directive dict,
+ HCfavor_e favorDecSpeed);
+
+
+LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ const limitedOutput_directive limit,
+ const dictCtx_directive dict
+ )
+{
+ typedef enum { lz4hc, lz4opt } lz4hc_strat_e;
+ typedef struct {
+ lz4hc_strat_e strat;
+ U32 nbSearches;
+ U32 targetLength;
+ } cParams_t;
+ static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = {
+ { lz4hc, 2, 16 }, /* 0, unused */
+ { lz4hc, 2, 16 }, /* 1, unused */
+ { lz4hc, 2, 16 }, /* 2, unused */
+ { lz4hc, 4, 16 }, /* 3 */
+ { lz4hc, 8, 16 }, /* 4 */
+ { lz4hc, 16, 16 }, /* 5 */
+ { lz4hc, 32, 16 }, /* 6 */
+ { lz4hc, 64, 16 }, /* 7 */
+ { lz4hc, 128, 16 }, /* 8 */
+ { lz4hc, 256, 16 }, /* 9 */
+ { lz4opt, 96, 64 }, /*10==LZ4HC_CLEVEL_OPT_MIN*/
+ { lz4opt, 512,128 }, /*11 */
+ { lz4opt,16384,LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */
+ };
+
+ DEBUGLOG(4, "LZ4HC_compress_generic(%p, %p, %d)", ctx, src, *srcSizePtr);
+
+ if (limit == limitedDestSize && dstCapacity < 1) return 0; /* Impossible to store anything */
+ if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */
+
+ ctx->end += *srcSizePtr;
+ if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */
+ cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
+ { cParams_t const cParam = clTable[cLevel];
+ HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio;
+ if (cParam.strat == lz4hc)
+ return LZ4HC_compress_hashChain(ctx,
+ src, dst, srcSizePtr, dstCapacity,
+ cParam.nbSearches, limit, dict);
+ assert(cParam.strat == lz4opt);
+ return LZ4HC_compress_optimal(ctx,
+ src, dst, srcSizePtr, dstCapacity,
+ cParam.nbSearches, cParam.targetLength, limit,
+ cLevel == LZ4HC_CLEVEL_MAX, /* ultra mode */
+ dict, favor);
+ }
+}
+
+static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock);
+
+static int LZ4HC_compress_generic_noDictCtx (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ limitedOutput_directive limit
+ )
{
- switch (compressionLevel) {
- default: return 0; /* unused */
- case 11: return 128;
- case 12: return 1<<10;
+ assert(ctx->dictCtx == NULL);
+ return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx);
+}
+
+static int LZ4HC_compress_generic_dictCtx (
+ LZ4HC_CCtx_internal* const ctx,
+ const char* const src,
+ char* const dst,
+ int* const srcSizePtr,
+ int const dstCapacity,
+ int cLevel,
+ limitedOutput_directive limit
+ )
+{
+ const size_t position = ctx->end - ctx->base - ctx->lowLimit;
+ assert(ctx->dictCtx != NULL);
+ if (position >= 64 KB) {
+ ctx->dictCtx = NULL;
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else if (position == 0 && *srcSizePtr > 4 KB) {
+ memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal));
+ LZ4HC_setExternalDict(ctx, (const BYTE *)src);
+ ctx->compressionLevel = (short)cLevel;
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else {
+ return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtx);
}
}
@@ -546,33 +809,21 @@ static int LZ4HC_compress_generic (
limitedOutput_directive limit
)
{
- if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe to reconsider */
- if (cLevel > 9) {
- if (limit == limitedDestSize) cLevel = 10;
- switch (cLevel) {
- case 10:
- return LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, 1 << 12, limit);
- case 11:
- ctx->searchNum = LZ4HC_getSearchNum(cLevel);
- return LZ4HC_compress_optimal(ctx, src, dst, *srcSizePtr, dstCapacity, limit, 128, 0);
- default:
- cLevel = 12;
- /* fall-through */
- case 12:
- ctx->searchNum = LZ4HC_getSearchNum(cLevel);
- return LZ4HC_compress_optimal(ctx, src, dst, *srcSizePtr, dstCapacity, limit, LZ4_OPT_NUM, 1);
- }
+ if (ctx->dictCtx == NULL) {
+ return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
+ } else {
+ return LZ4HC_compress_generic_dictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
}
- return LZ4HC_compress_hashChain(ctx, src, dst, srcSizePtr, dstCapacity, 1 << (cLevel-1), limit); /* levels 1-9 */
}
int LZ4_sizeofStateHC(void) { return sizeof(LZ4_streamHC_t); }
-int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
+int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
{
LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */
+ LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel);
LZ4HC_init (ctx, (const BYTE*)src);
if (dstCapacity < LZ4_compressBound(srcSize))
return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
@@ -580,10 +831,17 @@ int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int src
return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, noLimit);
}
+int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
+{
+ if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0; /* Error : state is not aligned for pointers (32 or 64 bits) */
+ LZ4_resetStreamHC ((LZ4_streamHC_t*)state, compressionLevel);
+ return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
+}
+
int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
{
#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
- LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t));
+ LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
#else
LZ4_streamHC_t state;
LZ4_streamHC_t* const statePtr = &state;
@@ -596,11 +854,11 @@ int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, in
}
/* LZ4_compress_HC_destSize() :
- * currently, only compatible with Hash Chain implementation,
- * hence limit compression level to LZ4HC_CLEVEL_OPT_MIN-1*/
+ * only compatible with regular HC parser */
int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
{
LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
+ LZ4_resetStreamHC((LZ4_streamHC_t*)LZ4HC_Data, cLevel);
LZ4HC_init(ctx, (const BYTE*) source);
return LZ4HC_compress_generic(ctx, source, dest, sourceSizePtr, targetDestSize, cLevel, limitedDestSize);
}
@@ -611,8 +869,15 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data, const char* source, char* dest, i
* Streaming Functions
**************************************/
/* allocation */
-LZ4_streamHC_t* LZ4_createStreamHC(void) { return (LZ4_streamHC_t*)malloc(sizeof(LZ4_streamHC_t)); }
-int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
+LZ4_streamHC_t* LZ4_createStreamHC(void) {
+ LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
+ if (LZ4_streamHCPtr==NULL) return NULL;
+ LZ4_resetStreamHC(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
+ return LZ4_streamHCPtr;
+}
+
+int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
+ DEBUGLOG(4, "LZ4_freeStreamHC(%p)", LZ4_streamHCPtr);
if (!LZ4_streamHCPtr) return 0; /* support free on NULL */
free(LZ4_streamHCPtr);
return 0;
@@ -623,47 +888,61 @@ int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr) {
void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
{
LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= sizeof(size_t) * LZ4_STREAMHCSIZE_SIZET); /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
+ DEBUGLOG(4, "LZ4_resetStreamHC(%p, %d)", LZ4_streamHCPtr, compressionLevel);
+ LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
+ LZ4_streamHCPtr->internal_donotuse.base = NULL;
+ LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+ LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0;
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
+}
+
+void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
+{
+ DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
+ LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
LZ4_streamHCPtr->internal_donotuse.base = NULL;
- if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX; /* cap compression level */
- LZ4_streamHCPtr->internal_donotuse.compressionLevel = compressionLevel;
- LZ4_streamHCPtr->internal_donotuse.searchNum = LZ4HC_getSearchNum(compressionLevel);
+ LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
+ LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
}
void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
{
- int const currentCLevel = LZ4_streamHCPtr->internal_donotuse.compressionLevel;
- int const minCLevel = currentCLevel < LZ4HC_CLEVEL_OPT_MIN ? 1 : LZ4HC_CLEVEL_OPT_MIN;
- int const maxCLevel = currentCLevel < LZ4HC_CLEVEL_OPT_MIN ? LZ4HC_CLEVEL_OPT_MIN-1 : LZ4HC_CLEVEL_MAX;
- compressionLevel = MIN(compressionLevel, minCLevel);
- compressionLevel = MAX(compressionLevel, maxCLevel);
- LZ4_streamHCPtr->internal_donotuse.compressionLevel = compressionLevel;
+ if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT;
+ if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;
+ LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel;
+}
+
+void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor)
+{
+ LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = (favor!=0);
}
int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize)
{
LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+ DEBUGLOG(4, "LZ4_loadDictHC(%p, %p, %d)", LZ4_streamHCPtr, dictionary, dictSize);
if (dictSize > 64 KB) {
dictionary += dictSize - 64 KB;
dictSize = 64 KB;
}
+ LZ4_resetStreamHC(LZ4_streamHCPtr, ctxPtr->compressionLevel);
LZ4HC_init (ctxPtr, (const BYTE*)dictionary);
ctxPtr->end = (const BYTE*)dictionary + dictSize;
- if (ctxPtr->compressionLevel >= LZ4HC_CLEVEL_OPT_MIN)
- LZ4HC_updateBinTree(ctxPtr, ctxPtr->end - MFLIMIT, ctxPtr->end - LASTLITERALS);
- else
- if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
+ if (dictSize >= 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3);
return dictSize;
}
+void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream) {
+ working_stream->internal_donotuse.dictCtx = dictionary_stream != NULL ? &(dictionary_stream->internal_donotuse) : NULL;
+}
/* compression */
static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock)
{
- if (ctxPtr->compressionLevel >= LZ4HC_CLEVEL_OPT_MIN)
- LZ4HC_updateBinTree(ctxPtr, ctxPtr->end - MFLIMIT, ctxPtr->end - LASTLITERALS);
- else
- if (ctxPtr->end >= ctxPtr->base + 4) LZ4HC_Insert (ctxPtr, ctxPtr->end-3); /* Referencing remaining dictionary content */
+ DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock);
+ if (ctxPtr->end >= ctxPtr->base + ctxPtr->dictLimit + 4)
+ LZ4HC_Insert (ctxPtr, ctxPtr->end-3); /* Referencing remaining dictionary content */
/* Only one memory segment for extDict, so any previous extDict is lost at this stage */
ctxPtr->lowLimit = ctxPtr->dictLimit;
@@ -680,6 +959,7 @@ static int LZ4_compressHC_continue_generic (LZ4_streamHC_t* LZ4_streamHCPtr,
limitedOutput_directive limit)
{
LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+ DEBUGLOG(4, "LZ4_compressHC_continue_generic(%p, %p, %d)", LZ4_streamHCPtr, src, *srcSizePtr);
/* auto-init if forgotten */
if (ctxPtr->base == NULL) LZ4HC_init (ctxPtr, (const BYTE*) src);
@@ -717,8 +997,6 @@ int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src,
int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int targetDestSize)
{
- LZ4HC_CCtx_internal* const ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
- if (ctxPtr->compressionLevel >= LZ4HC_CLEVEL_OPT_MIN) LZ4HC_init(ctxPtr, (const BYTE*)src); /* not compatible with btopt implementation */
return LZ4_compressHC_continue_generic(LZ4_streamHCPtr, src, dst, srcSizePtr, targetDestSize, limitedDestSize);
}
@@ -730,6 +1008,7 @@ int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int dictS
{
LZ4HC_CCtx_internal* const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
int const prefixSize = (int)(streamPtr->end - (streamPtr->base + streamPtr->dictLimit));
+ DEBUGLOG(4, "LZ4_saveDictHC(%p, %p, %d)", LZ4_streamHCPtr, safeBuffer, dictSize);
if (dictSize > 64 KB) dictSize = 64 KB;
if (dictSize < 4) dictSize = 0;
if (dictSize > prefixSize) dictSize = prefixSize;
@@ -769,17 +1048,17 @@ int LZ4_resetStreamStateHC(void* state, char* inputBuffer)
{
LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
if ((((size_t)state) & (sizeof(void*)-1)) != 0) return 1; /* Error : pointer is not aligned for pointer (32 or 64 bits) */
+ LZ4_resetStreamHC((LZ4_streamHC_t*)state, ((LZ4_streamHC_t*)state)->internal_donotuse.compressionLevel);
LZ4HC_init(ctx, (const BYTE*)inputBuffer);
- ctx->inputBuffer = (BYTE*)inputBuffer;
return 0;
}
-void* LZ4_createHC (char* inputBuffer)
+void* LZ4_createHC (const char* inputBuffer)
{
- LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOCATOR(1, sizeof(LZ4_streamHC_t));
+ LZ4_streamHC_t* hc4 = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
if (hc4 == NULL) return NULL; /* not enough memory */
+ LZ4_resetStreamHC(hc4, 0 /* compressionLevel */);
LZ4HC_init (&hc4->internal_donotuse, (const BYTE*)inputBuffer);
- hc4->internal_donotuse.inputBuffer = (BYTE*)inputBuffer;
return hc4;
}
@@ -801,7 +1080,333 @@ int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* src, c
char* LZ4_slideInputBufferHC(void* LZ4HC_Data)
{
- LZ4HC_CCtx_internal* const hc4 = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse;
- int const dictSize = LZ4_saveDictHC((LZ4_streamHC_t*)LZ4HC_Data, (char*)(hc4->inputBuffer), 64 KB);
- return (char*)(hc4->inputBuffer + dictSize);
+ LZ4_streamHC_t *ctx = (LZ4_streamHC_t*)LZ4HC_Data;
+ const BYTE *bufferStart = ctx->internal_donotuse.base + ctx->internal_donotuse.lowLimit;
+ LZ4_resetStreamHC_fast(ctx, ctx->internal_donotuse.compressionLevel);
+ /* avoid const char * -> char * conversion warning :( */
+ return (char *)(uptrval)bufferStart;
+}
+
+
+/* ================================================
+ * LZ4 Optimal parser (levels 10-12)
+ * ===============================================*/
+typedef struct {
+ int price;
+ int off;
+ int mlen;
+ int litlen;
+} LZ4HC_optimal_t;
+
+/* price in bytes */
+LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
+{
+ int price = litlen;
+ if (litlen >= (int)RUN_MASK)
+ price += 1 + (litlen-RUN_MASK)/255;
+ return price;
+}
+
+
+/* requires mlen >= MINMATCH */
+LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
+{
+ int price = 1 + 2 ; /* token + 16-bit offset */
+
+ price += LZ4HC_literalsPrice(litlen);
+
+ if (mlen >= (int)(ML_MASK+MINMATCH))
+ price += 1 + (mlen-(ML_MASK+MINMATCH))/255;
+
+ return price;
}
+
+
+typedef struct {
+ int off;
+ int len;
+} LZ4HC_match_t;
+
+LZ4_FORCE_INLINE LZ4HC_match_t
+LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx,
+ const BYTE* ip, const BYTE* const iHighLimit,
+ int minLen, int nbSearches,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
+{
+ LZ4HC_match_t match = { 0 , 0 };
+ const BYTE* matchPtr = NULL;
+ /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
+ * but this won't be the case here, as we define iLowLimit==ip,
+ * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
+ int matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /*patternAnalysis*/, 1 /*chainSwap*/, dict, favorDecSpeed);
+ if (matchLength <= minLen) return match;
+ if (favorDecSpeed) {
+ if ((matchLength>18) & (matchLength<=36)) matchLength=18; /* favor shortcut */
+ }
+ match.len = matchLength;
+ match.off = (int)(ip-matchPtr);
+ return match;
+}
+
+
+static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx,
+ const char* const source,
+ char* dst,
+ int* srcSizePtr,
+ int dstCapacity,
+ int const nbSearches,
+ size_t sufficient_len,
+ const limitedOutput_directive limit,
+ int const fullUpdate,
+ const dictCtx_directive dict,
+ const HCfavor_e favorDecSpeed)
+{
+#define TRAILING_LITERALS 3
+ LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS]; /* ~64 KB, which is a bit large for stack... */
+
+ const BYTE* ip = (const BYTE*) source;
+ const BYTE* anchor = ip;
+ const BYTE* const iend = ip + *srcSizePtr;
+ const BYTE* const mflimit = iend - MFLIMIT;
+ const BYTE* const matchlimit = iend - LASTLITERALS;
+ BYTE* op = (BYTE*) dst;
+ BYTE* opSaved = (BYTE*) dst;
+ BYTE* oend = op + dstCapacity;
+
+ /* init */
+ DEBUGLOG(5, "LZ4HC_compress_optimal");
+ *srcSizePtr = 0;
+ if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */
+ if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
+
+ /* Main Loop */
+ assert(ip - anchor < LZ4_MAX_INPUT_SIZE);
+ while (ip <= mflimit) {
+ int const llen = (int)(ip - anchor);
+ int best_mlen, best_off;
+ int cur, last_match_pos = 0;
+
+ LZ4HC_match_t const firstMatch = LZ4HC_FindLongerMatch(ctx, ip, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
+ if (firstMatch.len==0) { ip++; continue; }
+
+ if ((size_t)firstMatch.len > sufficient_len) {
+ /* good enough solution : immediate encoding */
+ int const firstML = firstMatch.len;
+ const BYTE* const matchPos = ip - firstMatch.off;
+ opSaved = op;
+ if ( LZ4HC_encodeSequence(&ip, &op, &anchor, firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */
+ goto _dest_overflow;
+ continue;
+ }
+
+ /* set prices for first positions (literals) */
+ { int rPos;
+ for (rPos = 0 ; rPos < MINMATCH ; rPos++) {
+ int const cost = LZ4HC_literalsPrice(llen + rPos);
+ opt[rPos].mlen = 1;
+ opt[rPos].off = 0;
+ opt[rPos].litlen = llen + rPos;
+ opt[rPos].price = cost;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
+ rPos, cost, opt[rPos].litlen);
+ } }
+ /* set prices using initial match */
+ { int mlen = MINMATCH;
+ int const matchML = firstMatch.len; /* necessarily < sufficient_len < LZ4_OPT_NUM */
+ int const offset = firstMatch.off;
+ assert(matchML < LZ4_OPT_NUM);
+ for ( ; mlen <= matchML ; mlen++) {
+ int const cost = LZ4HC_sequencePrice(llen, mlen);
+ opt[mlen].mlen = mlen;
+ opt[mlen].off = offset;
+ opt[mlen].litlen = llen;
+ opt[mlen].price = cost;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i) -- initial setup",
+ mlen, cost, mlen);
+ } }
+ last_match_pos = firstMatch.len;
+ { int addLit;
+ for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
+ opt[last_match_pos+addLit].mlen = 1; /* literal */
+ opt[last_match_pos+addLit].off = 0;
+ opt[last_match_pos+addLit].litlen = addLit;
+ opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
+ last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
+ } }
+
+ /* check further positions */
+ for (cur = 1; cur < last_match_pos; cur++) {
+ const BYTE* const curPtr = ip + cur;
+ LZ4HC_match_t newMatch;
+
+ if (curPtr > mflimit) break;
+ DEBUGLOG(7, "rPos:%u[%u] vs [%u]%u",
+ cur, opt[cur].price, opt[cur+1].price, cur+1);
+ if (fullUpdate) {
+ /* not useful to search here if next position has same (or lower) cost */
+ if ( (opt[cur+1].price <= opt[cur].price)
+ /* in some cases, next position has same cost, but cost rises sharply after, so a small match would still be beneficial */
+ && (opt[cur+MINMATCH].price < opt[cur].price + 3/*min seq price*/) )
+ continue;
+ } else {
+ /* not useful to search here if next position has same (or lower) cost */
+ if (opt[cur+1].price <= opt[cur].price) continue;
+ }
+
+ DEBUGLOG(7, "search at rPos:%u", cur);
+ if (fullUpdate)
+ newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
+ else
+ /* only test matches of minimum length; slightly faster, but misses a few bytes */
+ newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, last_match_pos - cur, nbSearches, dict, favorDecSpeed);
+ if (!newMatch.len) continue;
+
+ if ( ((size_t)newMatch.len > sufficient_len)
+ || (newMatch.len + cur >= LZ4_OPT_NUM) ) {
+ /* immediate encoding */
+ best_mlen = newMatch.len;
+ best_off = newMatch.off;
+ last_match_pos = cur + 1;
+ goto encode;
+ }
+
+ /* before match : set price with literals at beginning */
+ { int const baseLitlen = opt[cur].litlen;
+ int litlen;
+ for (litlen = 1; litlen < MINMATCH; litlen++) {
+ int const price = opt[cur].price - LZ4HC_literalsPrice(baseLitlen) + LZ4HC_literalsPrice(baseLitlen+litlen);
+ int const pos = cur + litlen;
+ if (price < opt[pos].price) {
+ opt[pos].mlen = 1; /* literal */
+ opt[pos].off = 0;
+ opt[pos].litlen = baseLitlen+litlen;
+ opt[pos].price = price;
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)",
+ pos, price, opt[pos].litlen);
+ } } }
+
+ /* set prices using match at position = cur */
+ { int const matchML = newMatch.len;
+ int ml = MINMATCH;
+
+ assert(cur + newMatch.len < LZ4_OPT_NUM);
+ for ( ; ml <= matchML ; ml++) {
+ int const pos = cur + ml;
+ int const offset = newMatch.off;
+ int price;
+ int ll;
+ DEBUGLOG(7, "testing price rPos %i (last_match_pos=%i)",
+ pos, last_match_pos);
+ if (opt[cur].mlen == 1) {
+ ll = opt[cur].litlen;
+ price = ((cur > ll) ? opt[cur - ll].price : 0)
+ + LZ4HC_sequencePrice(ll, ml);
+ } else {
+ ll = 0;
+ price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
+ }
+
+ assert((U32)favorDecSpeed <= 1);
+ if (pos > last_match_pos+TRAILING_LITERALS
+ || price <= opt[pos].price - (int)favorDecSpeed) {
+ DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i)",
+ pos, price, ml);
+ assert(pos < LZ4_OPT_NUM);
+ if ( (ml == matchML) /* last pos of last match */
+ && (last_match_pos < pos) )
+ last_match_pos = pos;
+ opt[pos].mlen = ml;
+ opt[pos].off = offset;
+ opt[pos].litlen = ll;
+ opt[pos].price = price;
+ } } }
+ /* complete following positions with literals */
+ { int addLit;
+ for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
+ opt[last_match_pos+addLit].mlen = 1; /* literal */
+ opt[last_match_pos+addLit].off = 0;
+ opt[last_match_pos+addLit].litlen = addLit;
+ opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
+ DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
+ } }
+ } /* for (cur = 1; cur <= last_match_pos; cur++) */
+
+ best_mlen = opt[last_match_pos].mlen;
+ best_off = opt[last_match_pos].off;
+ cur = last_match_pos - best_mlen;
+
+ encode: /* cur, last_match_pos, best_mlen, best_off must be set */
+ assert(cur < LZ4_OPT_NUM);
+ assert(last_match_pos >= 1); /* == 1 when only one candidate */
+ DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos);
+ { int candidate_pos = cur;
+ int selected_matchLength = best_mlen;
+ int selected_offset = best_off;
+ while (1) { /* from end to beginning */
+ int const next_matchLength = opt[candidate_pos].mlen; /* can be 1, means literal */
+ int const next_offset = opt[candidate_pos].off;
+ DEBUGLOG(7, "pos %i: sequence length %i", candidate_pos, selected_matchLength);
+ opt[candidate_pos].mlen = selected_matchLength;
+ opt[candidate_pos].off = selected_offset;
+ selected_matchLength = next_matchLength;
+ selected_offset = next_offset;
+ if (next_matchLength > candidate_pos) break; /* last match elected, first match to encode */
+ assert(next_matchLength > 0); /* can be 1, means literal */
+ candidate_pos -= next_matchLength;
+ } }
+
+ /* encode all recorded sequences in order */
+ { int rPos = 0; /* relative position (to ip) */
+ while (rPos < last_match_pos) {
+ int const ml = opt[rPos].mlen;
+ int const offset = opt[rPos].off;
+ if (ml == 1) { ip++; rPos++; continue; } /* literal; note: can end up with several literals, in which case, skip them */
+ rPos += ml;
+ assert(ml >= MINMATCH);
+ assert((offset >= 1) && (offset <= MAX_DISTANCE));
+ opSaved = op;
+ if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */
+ goto _dest_overflow;
+ } }
+ } /* while (ip <= mflimit) */
+
+ _last_literals:
+ /* Encode Last Literals */
+ { size_t lastRunSize = (size_t)(iend - anchor); /* literals */
+ size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255;
+ size_t const totalSize = 1 + litLength + lastRunSize;
+ if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */
+ if (limit && (op + totalSize > oend)) {
+ if (limit == limitedOutput) return 0; /* Check output limit */
+ /* adapt lastRunSize to fill 'dst' */
+ lastRunSize = (size_t)(oend - op) - 1;
+ litLength = (lastRunSize + 255 - RUN_MASK) / 255;
+ lastRunSize -= litLength;
+ }
+ ip = anchor + lastRunSize;
+
+ if (lastRunSize >= RUN_MASK) {
+ size_t accumulator = lastRunSize - RUN_MASK;
+ *op++ = (RUN_MASK << ML_BITS);
+ for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRunSize << ML_BITS);
+ }
+ memcpy(op, anchor, lastRunSize);
+ op += lastRunSize;
+ }
+
+ /* End */
+ *srcSizePtr = (int) (((const char*)ip) - source);
+ return (int) ((char*)op-dst);
+
+ _dest_overflow:
+ if (limit == limitedDestSize) {
+ op = opSaved; /* restore correct out pointer */
+ goto _last_literals;
+ }
+ return 0;
+ }
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
index dd9e26cd279..869c783884c 100644
--- a/lib/lz4hc.h
+++ b/lib/lz4hc.h
@@ -41,14 +41,14 @@ extern "C" {
#endif
/* --- Dependency --- */
-/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */
+/* note : lz4hc requires lz4.h/lz4.c for compilation */
#include "lz4.h" /* stddef, LZ4LIB_API, LZ4_DEPRECATED */
/* --- Useful constants --- */
#define LZ4HC_CLEVEL_MIN 3
#define LZ4HC_CLEVEL_DEFAULT 9
-#define LZ4HC_CLEVEL_OPT_MIN 11
+#define LZ4HC_CLEVEL_OPT_MIN 10
#define LZ4HC_CLEVEL_MAX 12
@@ -56,12 +56,12 @@ extern "C" {
* Block Compression
**************************************/
/*! LZ4_compress_HC() :
- * Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm.
+ * Compress data from `src` into `dst`, using the more powerful but slower "HC" algorithm.
* `dst` must be already allocated.
- * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
- * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
- * `compressionLevel` : Recommended values are between 4 and 9, although any value between 1 and LZ4HC_CLEVEL_MAX will work.
- * Values >LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.
+ * Compression is guaranteed to succeed if `dstCapacity >= LZ4_compressBound(srcSize)` (see "lz4.h")
+ * Max supported `srcSize` value is LZ4_MAX_INPUT_SIZE (see "lz4.h")
+ * `compressionLevel` : any value between 1 and LZ4HC_CLEVEL_MAX will work.
+ * Values > LZ4HC_CLEVEL_MAX behave the same as LZ4HC_CLEVEL_MAX.
* @return : the number of bytes written into 'dst'
* or 0 if compression fails.
*/
@@ -74,12 +74,12 @@ LZ4LIB_API int LZ4_compress_HC (const char* src, char* dst, int srcSize, int dst
/*! LZ4_compress_HC_extStateHC() :
- * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`.
+ * Same as LZ4_compress_HC(), but using an externally allocated memory segment for `state`.
* `state` size is provided by LZ4_sizeofStateHC().
- * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() will do properly).
+ * Memory segment must be aligned on 8-bytes boundaries (which a normal malloc() should do properly).
*/
-LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
LZ4LIB_API int LZ4_sizeofStateHC(void);
+LZ4LIB_API int LZ4_compress_HC_extStateHC(void* state, const char* src, char* dst, int srcSize, int maxDstSize, int compressionLevel);
/*-************************************
@@ -89,10 +89,10 @@ LZ4LIB_API int LZ4_sizeofStateHC(void);
typedef union LZ4_streamHC_u LZ4_streamHC_t; /* incomplete type (defined later) */
/*! LZ4_createStreamHC() and LZ4_freeStreamHC() :
- * These functions create and release memory for LZ4 HC streaming state.
- * Newly created states are automatically initialized.
- * Existing states can be re-used several times, using LZ4_resetStreamHC().
- * These methods are API and ABI stable, they can be used in combination with a DLL.
+ * These functions create and release memory for LZ4 HC streaming state.
+ * Newly created states are automatically initialized.
+ * Existing states can be re-used several times, using LZ4_resetStreamHC().
+ * These methods are API and ABI stable, they can be used in combination with a DLL.
*/
LZ4LIB_API LZ4_streamHC_t* LZ4_createStreamHC(void);
LZ4LIB_API int LZ4_freeStreamHC (LZ4_streamHC_t* streamHCPtr);
@@ -125,13 +125,13 @@ LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, in
*/
- /*-*************************************
+/*-**************************************************************
* PRIVATE DEFINITIONS :
* Do not use these definitions.
* They are exposed to allow static allocation of `LZ4_streamHC_t`.
* Using these definitions makes the code vulnerable to potential API break when upgrading LZ4
- **************************************/
-#define LZ4HC_DICTIONARY_LOGSIZE 17 /* because of btopt, hc would only need 16 */
+ ****************************************************************/
+#define LZ4HC_DICTIONARY_LOGSIZE 16
#define LZ4HC_MAXD (1<<LZ4HC_DICTIONARY_LOGSIZE)
#define LZ4HC_MAXD_MASK (LZ4HC_MAXD - 1)
@@ -143,41 +143,43 @@ LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, in
#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#include <stdint.h>
-typedef struct
+typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
+struct LZ4HC_CCtx_internal
{
uint32_t hashTable[LZ4HC_HASHTABLESIZE];
uint16_t chainTable[LZ4HC_MAXD];
const uint8_t* end; /* next block here to continue on current prefix */
const uint8_t* base; /* All index relative to this position */
const uint8_t* dictBase; /* alternate base for extDict */
- uint8_t* inputBuffer; /* deprecated */
uint32_t dictLimit; /* below that point, need extDict */
uint32_t lowLimit; /* below that point, no more dict */
uint32_t nextToUpdate; /* index from which to continue dictionary update */
- uint32_t searchNum; /* only for optimal parser */
- uint32_t compressionLevel;
-} LZ4HC_CCtx_internal;
+ short compressionLevel;
+ short favorDecSpeed;
+ const LZ4HC_CCtx_internal* dictCtx;
+};
#else
-typedef struct
+typedef struct LZ4HC_CCtx_internal LZ4HC_CCtx_internal;
+struct LZ4HC_CCtx_internal
{
unsigned int hashTable[LZ4HC_HASHTABLESIZE];
unsigned short chainTable[LZ4HC_MAXD];
const unsigned char* end; /* next block here to continue on current prefix */
const unsigned char* base; /* All index relative to this position */
const unsigned char* dictBase; /* alternate base for extDict */
- unsigned char* inputBuffer; /* deprecated */
unsigned int dictLimit; /* below that point, need extDict */
unsigned int lowLimit; /* below that point, no more dict */
unsigned int nextToUpdate; /* index from which to continue dictionary update */
- unsigned int searchNum; /* only for optimal parser */
- int compressionLevel;
-} LZ4HC_CCtx_internal;
+ short compressionLevel;
+ short favorDecSpeed;
+ const LZ4HC_CCtx_internal* dictCtx;
+};
#endif
-#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 393268 */
+#define LZ4_STREAMHCSIZE (4*LZ4HC_HASHTABLESIZE + 2*LZ4HC_MAXD + 56) /* 262200 */
#define LZ4_STREAMHCSIZE_SIZET (LZ4_STREAMHCSIZE / sizeof(size_t))
union LZ4_streamHC_u {
size_t table[LZ4_STREAMHCSIZE_SIZET];
@@ -199,26 +201,32 @@ union LZ4_streamHC_u {
/* see lz4.h LZ4_DISABLE_DEPRECATE_WARNINGS to turn off deprecation warnings */
/* deprecated compression functions */
-/* these functions will trigger warning messages in future releases */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC (const char* source, char* dest, int inputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC() instead") int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
-
-/* Deprecated Streaming functions using older model; should no longer be used */
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStreamHC() instead") void* LZ4_createHC (char* inputBuffer);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_saveDictHC() instead") char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") int LZ4_freeHC (void* LZ4HC_Data);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int LZ4_sizeofStreamStateHC(void);
-LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC(void* state, char* inputBuffer);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC (const char* source, char* dest, int inputSize);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize);
+LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_extStateHC() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
+LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+
+/* Obsolete streaming functions; degraded functionality; do not use!
+ *
+ * In order to perform streaming compression, these functions depended on data
+ * that is no longer tracked in the state. They have been preserved as well as
+ * possible: using them will still produce a correct output. However, use of
+ * LZ4_slideInputBufferHC() will truncate the history of the stream, rather
+ * than preserve a window-sized chunk of history.
+ */
+LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API void* LZ4_createHC (const char* inputBuffer);
+LZ4_DEPRECATED("use LZ4_saveDictHC() instead") LZ4LIB_API char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
+LZ4_DEPRECATED("use LZ4_freeStreamHC() instead") LZ4LIB_API int LZ4_freeHC (void* LZ4HC_Data);
+LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") LZ4LIB_API int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+LZ4_DEPRECATED("use LZ4_createStreamHC() instead") LZ4LIB_API int LZ4_sizeofStreamStateHC(void);
+LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") LZ4LIB_API int LZ4_resetStreamStateHC(void* state, char* inputBuffer);
#if defined (__cplusplus)
@@ -227,18 +235,23 @@ LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStr
#endif /* LZ4_HC_H_19834876238432 */
-/*-************************************************
+
+/*-**************************************************
* !!!!! STATIC LINKING ONLY !!!!!
* Following definitions are considered experimental.
* They should not be linked from DLL,
* as there is no guarantee of API stability yet.
* Prototypes will be promoted to "stable" status
* after successfull usage in real-life scenarios.
- *************************************************/
+ ***************************************************/
#ifdef LZ4_HC_STATIC_LINKING_ONLY /* protection macro */
#ifndef LZ4_HC_SLO_098092834
#define LZ4_HC_SLO_098092834
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
/*! LZ4_compress_HC_destSize() : v1.8.0 (experimental)
* Will try to compress as much data from `src` as possible
* that can fit into `targetDstSize` budget.
@@ -248,9 +261,9 @@ LZ4LIB_API LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStr
* `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`
*/
int LZ4_compress_HC_destSize(void* LZ4HC_Data,
- const char* src, char* dst,
- int* srcSizePtr, int targetDstSize,
- int compressionLevel);
+ const char* src, char* dst,
+ int* srcSizePtr, int targetDstSize,
+ int compressionLevel);
/*! LZ4_compress_HC_continue_destSize() : v1.8.0 (experimental)
* Similar as LZ4_compress_HC_continue(),
@@ -260,21 +273,85 @@ int LZ4_compress_HC_destSize(void* LZ4HC_Data,
* @return : the number of bytes written into 'dst'
* or 0 if compression fails.
* `srcSizePtr` : value will be updated to indicate how much bytes were read from `src`.
- * Important : due to limitations, this prototype only works well up to cLevel < LZ4HC_CLEVEL_OPT_MIN
- * beyond that level, compression performance will be much reduced due to internal incompatibilities
*/
int LZ4_compress_HC_continue_destSize(LZ4_streamHC_t* LZ4_streamHCPtr,
const char* src, char* dst,
int* srcSizePtr, int targetDstSize);
/*! LZ4_setCompressionLevel() : v1.8.0 (experimental)
- * It's possible to change compression level after LZ4_resetStreamHC(), between 2 invocations of LZ4_compress_HC_continue*(),
- * but that requires to stay in the same mode (aka 1-10 or 11-12).
- * This function ensures this condition.
+ * It's possible to change compression level between 2 invocations of LZ4_compress_HC_continue*()
*/
void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
+/*! LZ4_favorDecompressionSpeed() : v1.8.2 (experimental)
+ * Parser will select decisions favoring decompression over compression ratio.
+ * Only work at highest compression settings (level >= LZ4HC_CLEVEL_OPT_MIN)
+ */
+void LZ4_favorDecompressionSpeed(LZ4_streamHC_t* LZ4_streamHCPtr, int favor);
+
+/*! LZ4_resetStreamHC_fast() :
+ * When an LZ4_streamHC_t is known to be in a internally coherent state,
+ * it can often be prepared for a new compression with almost no work, only
+ * sometimes falling back to the full, expensive reset that is always required
+ * when the stream is in an indeterminate state (i.e., the reset performed by
+ * LZ4_resetStreamHC()).
+ *
+ * LZ4_streamHCs are guaranteed to be in a valid state when:
+ * - returned from LZ4_createStreamHC()
+ * - reset by LZ4_resetStreamHC()
+ * - memset(stream, 0, sizeof(LZ4_streamHC_t))
+ * - the stream was in a valid state and was reset by LZ4_resetStreamHC_fast()
+ * - the stream was in a valid state and was then used in any compression call
+ * that returned success
+ * - the stream was in an indeterminate state and was used in a compression
+ * call that fully reset the state (LZ4_compress_HC_extStateHC()) and that
+ * returned success
+ */
+void LZ4_resetStreamHC_fast(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
+
+/*! LZ4_compress_HC_extStateHC_fastReset() :
+ * A variant of LZ4_compress_HC_extStateHC().
+ *
+ * Using this variant avoids an expensive initialization step. It is only safe
+ * to call if the state buffer is known to be correctly initialized already
+ * (see above comment on LZ4_resetStreamHC_fast() for a definition of
+ * "correctly initialized"). From a high level, the difference is that this
+ * function initializes the provided state with a call to
+ * LZ4_resetStreamHC_fast() while LZ4_compress_HC_extStateHC() starts with a
+ * call to LZ4_resetStreamHC().
+ */
+int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel);
+
+/*! LZ4_attach_HC_dictionary() :
+ * This is an experimental API that allows for the efficient use of a
+ * static dictionary many times.
+ *
+ * Rather than re-loading the dictionary buffer into a working context before
+ * each compression, or copying a pre-loaded dictionary's LZ4_streamHC_t into a
+ * working LZ4_streamHC_t, this function introduces a no-copy setup mechanism,
+ * in which the working stream references the dictionary stream in-place.
+ *
+ * Several assumptions are made about the state of the dictionary stream.
+ * Currently, only streams which have been prepared by LZ4_loadDictHC() should
+ * be expected to work.
+ *
+ * Alternatively, the provided dictionary stream pointer may be NULL, in which
+ * case any existing dictionary stream is unset.
+ *
+ * A dictionary should only be attached to a stream without any history (i.e.,
+ * a stream that has just been reset).
+ *
+ * The dictionary will remain attached to the working stream only for the
+ * current stream session. Calls to LZ4_resetStreamHC(_fast) will remove the
+ * dictionary context association from the working stream. The dictionary
+ * stream (and source buffer) must remain in-place / accessible / unchanged
+ * through the lifetime of the stream session.
+ */
+LZ4LIB_API void LZ4_attach_HC_dictionary(LZ4_streamHC_t *working_stream, const LZ4_streamHC_t *dictionary_stream);
+#if defined (__cplusplus)
+}
+#endif
#endif /* LZ4_HC_SLO_098092834 */
#endif /* LZ4_HC_STATIC_LINKING_ONLY */
diff --git a/lib/lz4opt.h b/lib/lz4opt.h
deleted file mode 100644
index e9e54d86c2f..00000000000
--- a/lib/lz4opt.h
+++ /dev/null
@@ -1,366 +0,0 @@
-/*
- lz4opt.h - Optimal Mode of LZ4
- Copyright (C) 2015-2017, Przemyslaw Skibinski <inikep@gmail.com>
- Note : this file is intended to be included within lz4hc.c
-
- BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are
- met:
-
- * Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- * Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following disclaimer
- in the documentation and/or other materials provided with the
- distribution.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
- You can contact the author at :
- - LZ4 source repository : https://github.com/lz4/lz4
- - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
-*/
-
-#define LZ4_OPT_NUM (1<<12)
-
-
-typedef struct {
- int off;
- int len;
-} LZ4HC_match_t;
-
-typedef struct {
- int price;
- int off;
- int mlen;
- int litlen;
-} LZ4HC_optimal_t;
-
-
-/* price in bytes */
-FORCE_INLINE size_t LZ4HC_literalsPrice(size_t litlen)
-{
- size_t price = litlen;
- if (litlen >= (size_t)RUN_MASK)
- price += 1 + (litlen-RUN_MASK)/255;
- return price;
-}
-
-
-/* requires mlen >= MINMATCH */
-FORCE_INLINE size_t LZ4HC_sequencePrice(size_t litlen, size_t mlen)
-{
- size_t price = 2 + 1; /* 16-bit offset + token */
-
- price += LZ4HC_literalsPrice(litlen);
-
- if (mlen >= (size_t)(ML_MASK+MINMATCH))
- price+= 1 + (mlen-(ML_MASK+MINMATCH))/255;
-
- return price;
-}
-
-
-/*-*************************************
-* Binary Tree search
-***************************************/
-FORCE_INLINE int LZ4HC_BinTree_InsertAndGetAllMatches (
- LZ4HC_CCtx_internal* ctx,
- const BYTE* const ip,
- const BYTE* const iHighLimit,
- size_t best_mlen,
- LZ4HC_match_t* matches,
- int* matchNum)
-{
- U16* const chainTable = ctx->chainTable;
- U32* const HashTable = ctx->hashTable;
- const BYTE* const base = ctx->base;
- const U32 dictLimit = ctx->dictLimit;
- const U32 current = (U32)(ip - base);
- const U32 lowLimit = (ctx->lowLimit + MAX_DISTANCE > current) ? ctx->lowLimit : current - (MAX_DISTANCE - 1);
- const BYTE* const dictBase = ctx->dictBase;
- const BYTE* match;
- int nbAttempts = ctx->searchNum;
- int mnum = 0;
- U16 *ptr0, *ptr1, delta0, delta1;
- U32 matchIndex;
- size_t matchLength = 0;
- U32* HashPos;
-
- if (ip + MINMATCH > iHighLimit) return 1;
-
- /* HC4 match finder */
- HashPos = &HashTable[LZ4HC_hashPtr(ip)];
- matchIndex = *HashPos;
- *HashPos = current;
-
- ptr0 = &DELTANEXTMAXD(current*2+1);
- ptr1 = &DELTANEXTMAXD(current*2);
- delta0 = delta1 = (U16)(current - matchIndex);
-
- while ((matchIndex < current) && (matchIndex>=lowLimit) && (nbAttempts)) {
- nbAttempts--;
- if (matchIndex >= dictLimit) {
- match = base + matchIndex;
- matchLength = LZ4_count(ip, match, iHighLimit);
- } else {
- const BYTE* vLimit = ip + (dictLimit - matchIndex);
- match = dictBase + matchIndex;
- if (vLimit > iHighLimit) vLimit = iHighLimit;
- matchLength = LZ4_count(ip, match, vLimit);
- if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
- matchLength += LZ4_count(ip+matchLength, base+dictLimit, iHighLimit);
- if (matchIndex+matchLength >= dictLimit)
- match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
- }
-
- if (matchLength > best_mlen) {
- best_mlen = matchLength;
- if (matches) {
- if (matchIndex >= dictLimit)
- matches[mnum].off = (int)(ip - match);
- else
- matches[mnum].off = (int)(ip - (base + matchIndex)); /* virtual matchpos */
- matches[mnum].len = (int)matchLength;
- mnum++;
- }
- if (best_mlen > LZ4_OPT_NUM) break;
- }
-
- if (ip+matchLength >= iHighLimit) /* equal : no way to know if inf or sup */
- break; /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt the tree */
-
- DEBUGLOG(6, "ip :%016llX", (U64)ip);
- DEBUGLOG(6, "match:%016llX", (U64)match);
- if (*(ip+matchLength) < *(match+matchLength)) {
- *ptr0 = delta0;
- ptr0 = &DELTANEXTMAXD(matchIndex*2);
- if (*ptr0 == (U16)-1) break;
- delta0 = *ptr0;
- delta1 += delta0;
- matchIndex -= delta0;
- } else {
- *ptr1 = delta1;
- ptr1 = &DELTANEXTMAXD(matchIndex*2+1);
- if (*ptr1 == (U16)-1) break;
- delta1 = *ptr1;
- delta0 += delta1;
- matchIndex -= delta1;
- }
- }
-
- *ptr0 = (U16)-1;
- *ptr1 = (U16)-1;
- if (matchNum) *matchNum = mnum;
- /* if (best_mlen > 8) return best_mlen-8; */
- if (!matchNum) return 1;
- return 1;
-}
-
-
-FORCE_INLINE void LZ4HC_updateBinTree(LZ4HC_CCtx_internal* ctx, const BYTE* const ip, const BYTE* const iHighLimit)
-{
- const BYTE* const base = ctx->base;
- const U32 target = (U32)(ip - base);
- U32 idx = ctx->nextToUpdate;
- while(idx < target)
- idx += LZ4HC_BinTree_InsertAndGetAllMatches(ctx, base+idx, iHighLimit, 8, NULL, NULL);
-}
-
-
-/** Tree updater, providing best match */
-FORCE_INLINE int LZ4HC_BinTree_GetAllMatches (
- LZ4HC_CCtx_internal* ctx,
- const BYTE* const ip, const BYTE* const iHighLimit,
- size_t best_mlen, LZ4HC_match_t* matches, const int fullUpdate)
-{
- int mnum = 0;
- if (ip < ctx->base + ctx->nextToUpdate) return 0; /* skipped area */
- if (fullUpdate) LZ4HC_updateBinTree(ctx, ip, iHighLimit);
- best_mlen = LZ4HC_BinTree_InsertAndGetAllMatches(ctx, ip, iHighLimit, best_mlen, matches, &mnum);
- ctx->nextToUpdate = (U32)(ip - ctx->base + best_mlen);
- return mnum;
-}
-
-
-#define SET_PRICE(pos, ml, offset, ll, cost) \
-{ \
- while (last_pos < pos) { opt[last_pos+1].price = 1<<30; last_pos++; } \
- opt[pos].mlen = (int)ml; \
- opt[pos].off = (int)offset; \
- opt[pos].litlen = (int)ll; \
- opt[pos].price = (int)cost; \
-}
-
-
-static int LZ4HC_compress_optimal (
- LZ4HC_CCtx_internal* ctx,
- const char* const source,
- char* dest,
- int inputSize,
- int maxOutputSize,
- limitedOutput_directive limit,
- size_t sufficient_len,
- const int fullUpdate
- )
-{
- LZ4HC_optimal_t opt[LZ4_OPT_NUM + 1]; /* this uses a bit too much stack memory to my taste ... */
- LZ4HC_match_t matches[LZ4_OPT_NUM + 1];
-
- const BYTE* ip = (const BYTE*) source;
- const BYTE* anchor = ip;
- const BYTE* const iend = ip + inputSize;
- const BYTE* const mflimit = iend - MFLIMIT;
- const BYTE* const matchlimit = (iend - LASTLITERALS);
- BYTE* op = (BYTE*) dest;
- BYTE* const oend = op + maxOutputSize;
-
- /* init */
- DEBUGLOG(5, "LZ4HC_compress_optimal");
- if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
- ctx->end += inputSize;
- ip++;
-
- /* Main Loop */
- while (ip < mflimit) {
- size_t const llen = ip - anchor;
- size_t last_pos = 0;
- size_t match_num, cur, best_mlen, best_off;
- memset(opt, 0, sizeof(LZ4HC_optimal_t)); /* memset only the first one */
-
- match_num = LZ4HC_BinTree_GetAllMatches(ctx, ip, matchlimit, MINMATCH-1, matches, fullUpdate);
- if (!match_num) { ip++; continue; }
-
- if ((size_t)matches[match_num-1].len > sufficient_len) {
- /* good enough solution : immediate encoding */
- best_mlen = matches[match_num-1].len;
- best_off = matches[match_num-1].off;
- cur = 0;
- last_pos = 1;
- goto encode;
- }
-
- /* set prices using matches at position = 0 */
- { size_t matchNb;
- for (matchNb = 0; matchNb < match_num; matchNb++) {
- size_t mlen = (matchNb>0) ? (size_t)matches[matchNb-1].len+1 : MINMATCH;
- best_mlen = matches[matchNb].len; /* necessarily < sufficient_len < LZ4_OPT_NUM */
- for ( ; mlen <= best_mlen ; mlen++) {
- size_t const cost = LZ4HC_sequencePrice(llen, mlen) - LZ4HC_literalsPrice(llen);
- SET_PRICE(mlen, mlen, matches[matchNb].off, 0, cost); /* updates last_pos and opt[pos] */
- } } }
-
- if (last_pos < MINMATCH) { ip++; continue; } /* note : on clang at least, this test improves performance */
-
- /* check further positions */
- opt[0].mlen = opt[1].mlen = 1;
- for (cur = 1; cur <= last_pos; cur++) {
- const BYTE* const curPtr = ip + cur;
-
- /* establish baseline price if cur is literal */
- { size_t price, litlen;
- if (opt[cur-1].mlen == 1) {
- /* no match at previous position */
- litlen = opt[cur-1].litlen + 1;
- if (cur > litlen) {
- price = opt[cur - litlen].price + LZ4HC_literalsPrice(litlen);
- } else {
- price = LZ4HC_literalsPrice(llen + litlen) - LZ4HC_literalsPrice(llen);
- }
- } else {
- litlen = 1;
- price = opt[cur - 1].price + LZ4HC_literalsPrice(1);
- }
-
- if (price < (size_t)opt[cur].price)
- SET_PRICE(cur, 1 /*mlen*/, 0 /*off*/, litlen, price); /* note : increases last_pos */
- }
-
- if (cur == last_pos || curPtr >= mflimit) break;
-
- match_num = LZ4HC_BinTree_GetAllMatches(ctx, curPtr, matchlimit, MINMATCH-1, matches, fullUpdate);
- if ((match_num > 0) && (size_t)matches[match_num-1].len > sufficient_len) {
- /* immediate encoding */
- best_mlen = matches[match_num-1].len;
- best_off = matches[match_num-1].off;
- last_pos = cur + 1;
- goto encode;
- }
-
- /* set prices using matches at position = cur */
- { size_t matchNb;
- for (matchNb = 0; matchNb < match_num; matchNb++) {
- size_t ml = (matchNb>0) ? (size_t)matches[matchNb-1].len+1 : MINMATCH;
- best_mlen = (cur + matches[matchNb].len < LZ4_OPT_NUM) ?
- (size_t)matches[matchNb].len : LZ4_OPT_NUM - cur;
-
- for ( ; ml <= best_mlen ; ml++) {
- size_t ll, price;
- if (opt[cur].mlen == 1) {
- ll = opt[cur].litlen;
- if (cur > ll)
- price = opt[cur - ll].price + LZ4HC_sequencePrice(ll, ml);
- else
- price = LZ4HC_sequencePrice(llen + ll, ml) - LZ4HC_literalsPrice(llen);
- } else {
- ll = 0;
- price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
- }
-
- if (cur + ml > last_pos || price < (size_t)opt[cur + ml].price) {
- SET_PRICE(cur + ml, ml, matches[matchNb].off, ll, price);
- } } } }
- } /* for (cur = 1; cur <= last_pos; cur++) */
-
- best_mlen = opt[last_pos].mlen;
- best_off = opt[last_pos].off;
- cur = last_pos - best_mlen;
-
-encode: /* cur, last_pos, best_mlen, best_off must be set */
- opt[0].mlen = 1;
- while (1) { /* from end to beginning */
- size_t const ml = opt[cur].mlen;
- int const offset = opt[cur].off;
- opt[cur].mlen = (int)best_mlen;
- opt[cur].off = (int)best_off;
- best_mlen = ml;
- best_off = offset;
- if (ml > cur) break; /* can this happen ? */
- cur -= ml;
- }
-
- /* encode all recorded sequences */
- cur = 0;
- while (cur < last_pos) {
- int const ml = opt[cur].mlen;
- int const offset = opt[cur].off;
- if (ml == 1) { ip++; cur++; continue; }
- cur += ml;
- if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) return 0;
- }
- } /* while (ip < mflimit) */
-
- /* Encode Last Literals */
- { int lastRun = (int)(iend - anchor);
- if ((limit) && (((char*)op - dest) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)maxOutputSize)) return 0; /* Check output limit */
- if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK<<ML_BITS); lastRun-=RUN_MASK; for(; lastRun > 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; }
- else *op++ = (BYTE)(lastRun<<ML_BITS);
- memcpy(op, anchor, iend - anchor);
- op += iend-anchor;
- }
-
- /* End */
- return (int) ((char*)op-dest);
-}
diff --git a/lib/xxhash.c b/lib/xxhash.c
index ac6e7c0fece..3fc97fd2a38 100644
--- a/lib/xxhash.c
+++ b/lib/xxhash.c
@@ -115,21 +115,21 @@ static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcp
# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
#endif
-#ifndef FORCE_INLINE
+#ifndef XXH_FORCE_INLINE
# ifdef _MSC_VER /* Visual Studio */
-# define FORCE_INLINE static __forceinline
+# define XXH_FORCE_INLINE static __forceinline
# else
# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
# ifdef __GNUC__
-# define FORCE_INLINE static inline __attribute__((always_inline))
+# define XXH_FORCE_INLINE static inline __attribute__((always_inline))
# else
-# define FORCE_INLINE static inline
+# define XXH_FORCE_INLINE static inline
# endif
# else
-# define FORCE_INLINE static
+# define XXH_FORCE_INLINE static
# endif /* __STDC_VERSION__ */
# endif /* _MSC_VER */
-#endif /* FORCE_INLINE */
+#endif /* XXH_FORCE_INLINE */
/* *************************************
@@ -223,7 +223,7 @@ typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
*****************************/
typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
-FORCE_INLINE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
+XXH_FORCE_INLINE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
{
if (align==XXH_unaligned)
return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
@@ -231,7 +231,7 @@ FORCE_INLINE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_a
return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
}
-FORCE_INLINE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
+XXH_FORCE_INLINE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
{
return XXH_readLE32_align(ptr, endian, XXH_unaligned);
}
@@ -266,7 +266,7 @@ static U32 XXH32_round(U32 seed, U32 input)
return seed;
}
-FORCE_INLINE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)
+XXH_FORCE_INLINE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)
{
const BYTE* p = (const BYTE*)input;
const BYTE* bEnd = p + len;
@@ -381,7 +381,7 @@ XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int s
}
-FORCE_INLINE XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
+XXH_FORCE_INLINE XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
{
const BYTE* p = (const BYTE*)input;
const BYTE* const bEnd = p + len;
@@ -451,7 +451,7 @@ XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void*
-FORCE_INLINE U32 XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
+XXH_FORCE_INLINE U32 XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
{
const BYTE * p = (const BYTE*)state->mem32;
const BYTE* const bEnd = (const BYTE*)(state->mem32) + state->memsize;
@@ -583,7 +583,7 @@ static U64 XXH_swap64 (U64 x)
}
#endif
-FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
+XXH_FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
{
if (align==XXH_unaligned)
return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
@@ -591,7 +591,7 @@ FORCE_INLINE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_a
return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
}
-FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
+XXH_FORCE_INLINE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
{
return XXH_readLE64_align(ptr, endian, XXH_unaligned);
}
@@ -626,7 +626,7 @@ static U64 XXH64_mergeRound(U64 acc, U64 val)
return acc;
}
-FORCE_INLINE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)
+XXH_FORCE_INLINE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)
{
const BYTE* p = (const BYTE*)input;
const BYTE* const bEnd = p + len;
@@ -750,7 +750,7 @@ XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long
return XXH_OK;
}
-FORCE_INLINE XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
+XXH_FORCE_INLINE XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
{
const BYTE* p = (const BYTE*)input;
const BYTE* const bEnd = p + len;
@@ -815,7 +815,7 @@ XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void*
return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
}
-FORCE_INLINE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
+XXH_FORCE_INLINE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
{
const BYTE * p = (const BYTE*)state->mem64;
const BYTE* const bEnd = (const BYTE*)state->mem64 + state->memsize;
--
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