DarkflameServer/dCommon/ZCompression.cpp

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#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;
}
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}
inflateEnd(&zInfo); // zlib function
return(nRet);
}
}