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/*=========================================================================
Program: Visualization Toolkit
Module: vtkZLibDataCompressor.cxx
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
#include "vtkZLibDataCompressor.h"
#include "vtkObjectFactory.h"
#include "vtk_zlib.h"
vtkStandardNewMacro(vtkZLibDataCompressor);
//----------------------------------------------------------------------------
vtkZLibDataCompressor::vtkZLibDataCompressor()
{
this->CompressionLevel = Z_DEFAULT_COMPRESSION;
}
//----------------------------------------------------------------------------
vtkZLibDataCompressor::~vtkZLibDataCompressor()
{
}
//----------------------------------------------------------------------------
void vtkZLibDataCompressor::PrintSelf(ostream& os, vtkIndent indent)
{
this->Superclass::PrintSelf(os,indent);
os << indent << "CompressionLevel: " << this->CompressionLevel << endl;
}
//----------------------------------------------------------------------------
size_t
vtkZLibDataCompressor::CompressBuffer(unsigned char const* uncompressedData,
size_t uncompressedSize,
unsigned char* compressedData,
size_t compressionSpace)
{
uLongf cs = static_cast<uLongf>(compressionSpace);
Bytef* cd = reinterpret_cast<Bytef*>(compressedData);
const Bytef* ud = reinterpret_cast<const Bytef*>(uncompressedData);
uLong us = static_cast<uLong>(uncompressedSize);
// Call zlib's compress function.
if(compress2(cd, &cs, ud, us, this->CompressionLevel) != Z_OK)
{
vtkErrorMacro("Zlib error while compressing data.");
return 0;
}
return static_cast<size_t>(cs);
}
//----------------------------------------------------------------------------
size_t
vtkZLibDataCompressor::UncompressBuffer(unsigned char const* compressedData,
size_t compressedSize,
unsigned char* uncompressedData,
size_t uncompressedSize)
{
uLongf us = static_cast<uLongf>(uncompressedSize);
Bytef* ud = reinterpret_cast<Bytef*>(uncompressedData);
const Bytef* cd = reinterpret_cast<const Bytef*>(compressedData);
uLong cs = static_cast<uLong>(compressedSize);
// Call zlib's uncompress function.
if(uncompress(ud, &us, cd, cs) != Z_OK)
{
vtkErrorMacro("Zlib error while uncompressing data.");
return 0;
}
// Make sure the output size matched that expected.
if(us != static_cast<uLongf>(uncompressedSize))
{
vtkErrorMacro("Decompression produced incorrect size.\n"
"Expected " << uncompressedSize << " and got " << us);
return 0;
}
return static_cast<size_t>(us);
}
//----------------------------------------------------------------------------
size_t
vtkZLibDataCompressor::GetMaximumCompressionSpace(size_t size)
{
// ZLib specifies that destination buffer must be 0.1% larger + 12 bytes.
return size + (size+999)/1000 + 12;
}
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