/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:		H5FDint.c
 *			Jan 17 2008
 *			Quincey Koziol <koziol@hdfgroup.org>
 *
 * Purpose:		Internal routine for VFD operations
 *
 *-------------------------------------------------------------------------
 */

/****************/
/* Module Setup */
/****************/

#include "H5FDmodule.h"         /* This source code file is part of the H5FD module */


/***********/
/* Headers */
/***********/
#include "H5private.h"		/* Generic Functions			*/
#include "H5CXprivate.h"        /* API Contexts                         */
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5Fprivate.h"         /* File access				*/
#include "H5FDpkg.h"		/* File Drivers				*/
#include "H5Iprivate.h"		/* IDs			  		*/


/****************/
/* Local Macros */
/****************/


/******************/
/* Local Typedefs */
/******************/


/********************/
/* Package Typedefs */
/********************/


/********************/
/* Local Prototypes */
/********************/


/*********************/
/* Package Variables */
/*********************/


/*****************************/
/* Library Private Variables */
/*****************************/


/*******************/
/* Local Variables */
/*******************/



/*-------------------------------------------------------------------------
 * Function:    H5FD_locate_signature
 *
 * Purpose:     Finds the HDF5 superblock signature in a file.  The
 *              signature can appear at address 0, or any power of two
 *              beginning with 512.
 *
 * Return:      Success:        SUCCEED
 *              Failure:        FAIL
 *
 * Programmer:  Robb Matzke
 *              Friday, November  7, 1997
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5FD_locate_signature(H5FD_t *file, haddr_t *sig_addr)
{
    haddr_t         addr, eoa, eof;
    uint8_t         buf[H5F_SIGNATURE_LEN];
    unsigned        n, maxpow;
    herr_t          ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Sanity checks */
    HDassert(file);

    /* Find the least N such that 2^N is larger than the file size */
    eof = H5FD_get_eof(file, H5FD_MEM_SUPER);
    eoa = H5FD_get_eoa(file, H5FD_MEM_SUPER);
    addr = MAX(eof, eoa);
    if(HADDR_UNDEF == addr)
        HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to obtain EOF/EOA value")
    for(maxpow = 0; addr; maxpow++)
        addr >>= 1;
    maxpow = MAX(maxpow, 9);

    /*
     * Search for the file signature at format address zero followed by
     * powers of two larger than 9.
     */
    for(n = 8; n < maxpow; n++) {
        addr = (8 == n) ? 0 : (haddr_t)1 << n;
        if(H5FD_set_eoa(file, H5FD_MEM_SUPER, addr + H5F_SIGNATURE_LEN) < 0)
            HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to set EOA value for file signature")
        if(H5FD_read(file, H5FD_MEM_SUPER, addr, (size_t)H5F_SIGNATURE_LEN, buf) < 0)
            HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to read file signature")
        if(!HDmemcmp(buf, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN))
            break;
    } /* end for */

    /*
     * If the signature was not found then reset the EOA value and return
     * HADDR_UNDEF.
     */
    if(n >= maxpow) {
        if(H5FD_set_eoa(file, H5FD_MEM_SUPER, eoa) < 0)
            HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to reset EOA value")
        *sig_addr = HADDR_UNDEF;
    } /* end if */
    else
        /* Set return value */
        *sig_addr = addr;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_locate_signature() */


/*-------------------------------------------------------------------------
 * Function:	H5FD_read
 *
 * Purpose:	Private version of H5FDread()
 *
 * Return:	Success:	Non-negative
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5FD_read(H5FD_t *file, H5FD_mem_t type, haddr_t addr, size_t size,
    void *buf/*out*/)
{
    hid_t dxpl_id;                      /* DXPL for operation */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Sanity checks */
    HDassert(file && file->cls);
    HDassert(buf);

    /* Get proper DXPL for I/O */
    dxpl_id = H5CX_get_dxpl();

#ifndef H5_HAVE_PARALLEL
    /* Do not return early for Parallel mode since the I/O could be a */
    /* collective transfer. */
    /* The no-op case */
    if(0 == size)
        HGOTO_DONE(SUCCEED)
#endif /* H5_HAVE_PARALLEL */

    /* 
     * If the file is open for SWMR read access, allow access to data past
     * the end of the allocated space (the 'eoa').  This is done because the
     * eoa stored in the file's superblock might be out of sync with the
     * objects being written within the file by the application performing
     * SWMR write operations.
     */
    if(!(file->access_flags & H5F_ACC_SWMR_READ)) {
        haddr_t     eoa;

        if(HADDR_UNDEF == (eoa = (file->cls->get_eoa)(file, type)))
            HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, "driver get_eoa request failed")

         if((addr + file->base_addr + size) > eoa)
            HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "addr overflow, addr = %llu, size = %llu, eoa = %llu", (unsigned long long)(addr + file->base_addr), (unsigned long long)size, (unsigned long long)eoa)
    } /* end if */

    /* Dispatch to driver */
    if((file->cls->read)(file, type, dxpl_id, addr + file->base_addr, size, buf) < 0)
        HGOTO_ERROR(H5E_VFL, H5E_READERROR, FAIL, "driver read request failed")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_read() */


/*-------------------------------------------------------------------------
 * Function:	H5FD_write
 *
 * Purpose:	Private version of H5FDwrite()
 *
 * Return:	Success:	Non-negative
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5FD_write(H5FD_t *file, H5FD_mem_t type, haddr_t addr, size_t size,
    const void *buf)
{
    hid_t dxpl_id;                      /* DXPL for operation */
    haddr_t eoa = HADDR_UNDEF;          /* EOA for file */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Sanity checks */
    HDassert(file && file->cls);
    HDassert(buf);

    /* Get proper DXPL for I/O */
    dxpl_id = H5CX_get_dxpl();

#ifndef H5_HAVE_PARALLEL
    /* Do not return early for Parallel mode since the I/O could be a */
    /* collective transfer. */
    /* The no-op case */
    if(0 == size)
        HGOTO_DONE(SUCCEED)
#endif /* H5_HAVE_PARALLEL */

    if(HADDR_UNDEF == (eoa = (file->cls->get_eoa)(file, type)))
	HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, "driver get_eoa request failed")
    if((addr + file->base_addr + size) > eoa)
        HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "addr overflow, addr = %llu, size=%llu, eoa=%llu", 
                    (unsigned long long)(addr+ file->base_addr), (unsigned long long)size, (unsigned long long)eoa)

    /* Dispatch to driver */
    if((file->cls->write)(file, type, dxpl_id, addr + file->base_addr, size, buf) < 0)
        HGOTO_ERROR(H5E_VFL, H5E_WRITEERROR, FAIL, "driver write request failed")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_write() */


/*-------------------------------------------------------------------------
 * Function:	H5FD_set_eoa
 *
 * Purpose:	Private version of H5FDset_eoa()
 *
 *              This function expects the EOA is a RELATIVE address, i.e.
 *              relative to the base address.  This is NOT the same as the
 *              EOA stored in the superblock, which is an absolute
 *              address.  Object addresses are relative.
 *
 * Return:	Success:	Non-negative
 *		Failure:	Negative, no side effect
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5FD_set_eoa(H5FD_t *file, H5FD_mem_t type, haddr_t addr)
{
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    HDassert(file && file->cls);
    HDassert(H5F_addr_defined(addr) && addr <= file->maxaddr);

    /* Dispatch to driver, convert to absolute address */
    if((file->cls->set_eoa)(file, type, addr + file->base_addr) < 0)
	HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, "driver set_eoa request failed")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_set_eoa() */


/*-------------------------------------------------------------------------
 * Function:	H5FD_get_eoa
 *
 * Purpose:	Private version of H5FDget_eoa()
 *
 *              This function returns the EOA as a RELATIVE address, i.e.
 *              relative to the base address.  This is NOT the same as the
 *              EOA stored in the superblock, which is an absolute
 *              address.  Object addresses are relative.
 *
 * Return:	Success:	First byte after allocated memory.
 *		Failure:	HADDR_UNDEF
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 *-------------------------------------------------------------------------
 */
haddr_t
H5FD_get_eoa(const H5FD_t *file, H5FD_mem_t type)
{
    haddr_t ret_value = HADDR_UNDEF;    /* Return value */

    FUNC_ENTER_NOAPI(HADDR_UNDEF)

    HDassert(file && file->cls);

    /* Dispatch to driver */
    if(HADDR_UNDEF == (ret_value = (file->cls->get_eoa)(file, type)))
	HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, HADDR_UNDEF, "driver get_eoa request failed")

    /* Adjust for base address in file (convert to relative address) */
    ret_value -= file->base_addr;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_get_eoa() */


/*-------------------------------------------------------------------------
 * Function:	H5FD_get_eof
 *
 * Purpose:	Private version of H5FDget_eof()
 *
 *              This function returns the EOF as a RELATIVE address, i.e.
 *              relative to the base address.  This will be different
 *              from  the end of the physical file if there is a user
 *              block.
 *
 * Return:	Success:	The EOF address.
 *
 *		Failure:	HADDR_UNDEF
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
haddr_t
H5FD_get_eof(const H5FD_t *file, H5FD_mem_t type)
{
    haddr_t ret_value = HADDR_UNDEF;    /* Return value */

    FUNC_ENTER_NOAPI(HADDR_UNDEF)

    HDassert(file && file->cls);

    /* Dispatch to driver */
    if(file->cls->get_eof) {
	if(HADDR_UNDEF == (ret_value = (file->cls->get_eof)(file, type)))
	    HGOTO_ERROR(H5E_VFL, H5E_CANTGET, HADDR_UNDEF, "driver get_eof request failed")
    } /* end if */
    else
	ret_value = file->maxaddr;

    /* Adjust for base address in file (convert to relative address)  */
    ret_value -= file->base_addr;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_get_eof() */


/*-------------------------------------------------------------------------
* Function:    H5FD_driver_query
*
* Purpose: Similar to H5FD_query(), but intended for cases when we don't
*          have a file available (e.g. before one is opened). Since we
*          can't use the file to get the driver, the driver is passed in
*          as a parameter.
*
* Return:  SUCCEED/FAIL
*
* Programmer:  Jacob Gruber
*              Wednesday, August 17, 2011
*
*-------------------------------------------------------------------------
*/
herr_t
H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/)
{
    herr_t ret_value = SUCCEED;          /* Return value */

    FUNC_ENTER_NOAPI_NOINIT_NOERR

    HDassert(driver);
    HDassert(flags);

    /* Check for the driver to query and then query it */
    if(driver->query)
        ret_value = (driver->query)(NULL, flags);
    else 
        *flags = 0;

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5FD_driver_query() */

