DarkflameServer/dCommon/ZCompression.cpp
2021-12-05 18:54:36 +01:00

73 lines
2.3 KiB
C++

#include "ZCompression.h"
#include <zlib.h>
namespace ZCompression
{
int32_t GetMaxCompressedLength(int32_t nLenSrc)
{
int32_t n16kBlocks = (nLenSrc + 16383) / 16384; // round up any fraction of a block
return (nLenSrc + 6 + (n16kBlocks * 5));
}
int32_t Compress(const uint8_t* abSrc, int32_t nLenSrc, uint8_t* abDst, int32_t nLenDst)
{
z_stream zInfo = { 0 };
zInfo.total_in = zInfo.avail_in = nLenSrc;
zInfo.total_out = zInfo.avail_out = nLenDst;
zInfo.next_in = const_cast<Bytef*>(abSrc);
zInfo.next_out = abDst;
int nErr, nRet = -1;
nErr = deflateInit(&zInfo, Z_DEFAULT_COMPRESSION); // zlib function
if (nErr == Z_OK) {
nErr = deflate(&zInfo, Z_FINISH); // zlib function
if (nErr == Z_STREAM_END) {
nRet = zInfo.total_out;
}
}
deflateEnd(&zInfo); // zlib function
return(nRet);
}
int32_t Decompress(const uint8_t* abSrc, int32_t nLenSrc, uint8_t* abDst, int32_t nLenDst, int32_t& nErr)
{
// Get the size of the decompressed data
z_stream zInfo = { 0 };
zInfo.total_in = zInfo.avail_in = nLenSrc;
zInfo.total_out = zInfo.avail_out = nLenDst;
zInfo.next_in = const_cast<Bytef*>(abSrc);
zInfo.next_out = abDst;
int nRet = -1;
nErr = inflateInit(&zInfo); // zlib function
if (nErr == Z_OK) {
nErr = inflate(&zInfo, Z_FINISH); // zlib function
if (nErr == Z_STREAM_END) {
nRet = zInfo.total_out;
}
}
inflateEnd(&zInfo); // zlib function
return(nRet);
/*
z_stream zInfo = { 0 };
zInfo.total_in = zInfo.avail_in = nLenSrc;
zInfo.total_out = zInfo.avail_out = nLenDst;
zInfo.next_in = const_cast<Bytef*>(abSrc);
zInfo.next_out = const_cast<Bytef*>(abDst);
int nRet = -1;
nErr = inflateInit(&zInfo); // zlib function
if (nErr == Z_OK) {
nErr = inflate(&zInfo, Z_FINISH); // zlib function
if (nErr == Z_STREAM_END) {
nRet = zInfo.total_out;
}
}
inflateEnd(&zInfo); // zlib function
return(nRet); // -1 or len of output
*/
}
}