vtkArchiver: add method to check for entry in archive

Common/Archive/vtkBufferedArchiver.cxx

@@ -19,12 +19,15 @@
 #include <archive.h>
 #include <archive_entry.h>
 
+#include <set>
+
 struct vtkBufferedArchiver::Internal
 {
   struct archive* Archive;
   char* Buffer;
   size_t AllocatedSize;
   size_t BufferSize;
+  std::set<std::string> Entries;
 };
 
 //----------------------------------------------------------------------------
@@ -85,6 +88,14 @@ void vtkBufferedArchiver::InsertIntoArchive(
   archive_write_header(this->Internals->Archive, entry);
   archive_write_data(this->Internals->Archive, data, size);
   archive_entry_free(entry);
+
+  this->Internals->Entries.insert(relativePath);
+}
+
+//----------------------------------------------------------------------------
+bool vtkBufferedArchiver::Contains(const std::string& relativePath)
+{
+  return this->Internals->Entries.find(relativePath) != this->Internals->Entries.end();
 }
 
 //----------------------------------------------------------------------------

Common/Archive/vtkBufferedArchiver.h

@@ -59,6 +59,13 @@ public:
     const std::string& relativePath, const char* data, std::streamsize size) override;
   //@}
 
+  //@{
+  /**
+   * Checks if \p relativePath represents an entry in the archive.
+   */
+  bool Contains(const std::string& relativePath) override;
+  //@}
+
   //@{
   /**
    * Access the buffer.

Common/Archive/vtkPartitionedArchiver.cxx

@@ -119,6 +119,12 @@ void vtkPartitionedArchiver::InsertIntoArchive(
   this->Internals->Buffers[relativePath] = std::make_pair(used, b);
 }
 
+//----------------------------------------------------------------------------
+bool vtkPartitionedArchiver::Contains(const std::string& relativePath)
+{
+  return this->Internals->Buffers.find(relativePath) != this->Internals->Buffers.end();
+}
+
 //----------------------------------------------------------------------------
 const char* vtkPartitionedArchiver::GetBuffer(const char* relativePath)
 {

Common/Archive/vtkPartitionedArchiver.h

@@ -60,6 +60,13 @@ public:
     const std::string& relativePath, const char* data, std::streamsize size) override;
   //@}
 
+  //@{
+  /**
+   * Checks if \p relativePath represents an entry in the archive.
+   */
+  bool Contains(const std::string& relativePath) override;
+  //@}
+
   //@{
   /**
    * Access the buffer.

Common/Core/vtkArchiver.cxx

@@ -68,6 +68,15 @@ void vtkArchiver::InsertIntoArchive(
   out.close();
 }
 
+//----------------------------------------------------------------------------
+bool vtkArchiver::Contains(const std::string& relativePath)
+{
+  std::stringstream path;
+  path << this->ArchiveName << "/" << relativePath;
+
+  return vtksys::SystemTools::FileExists(vtksys::SystemTools::GetFilenamePath(path.str()), true);
+}
+
 //----------------------------------------------------------------------------
 void vtkArchiver::PrintSelf(ostream& os, vtkIndent indent)
 {

Common/Core/vtkArchiver.h

@@ -70,6 +70,13 @@ public:
     const std::string& relativePath, const char* data, std::streamsize size);
   //@}
 
+  //@{
+  /**
+   * Checks if \p relativePath represents an entry in the archive.
+   */
+  virtual bool Contains(const std::string& relativePath);
+  //@}
+
 protected:
   vtkArchiver();
   ~vtkArchiver() override;