minetestmapper/ZlibDecompressor.cpp

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/*
* =====================================================================
* Version: 1.0
* Created: 18.09.2012 10:20:47
* Author: Miroslav Bendík
* Company: LinuxOS.sk
* =====================================================================
*/
#include <zlib.h>
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#include <stdint.h>
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#include "ZlibDecompressor.h"
ZlibDecompressor::ZlibDecompressor(const unsigned char *data, std::size_t size):
m_data(data),
m_seekPos(0),
m_size(size)
{
}
ZlibDecompressor::~ZlibDecompressor()
{
}
void ZlibDecompressor::setSeekPos(std::size_t seekPos)
{
m_seekPos = seekPos;
}
std::size_t ZlibDecompressor::seekPos() const
{
return m_seekPos;
}
ZlibDecompressor::string ZlibDecompressor::decompress()
{
const unsigned char *data = m_data + m_seekPos;
const std::size_t size = m_size - m_seekPos;
string buffer;
const size_t BUFSIZE = 128 * 1024;
uint8_t temp_buffer[BUFSIZE];
z_stream strm;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.next_in = Z_NULL;
strm.avail_in = size;
if (inflateInit(&strm) != Z_OK) {
throw DecompressError();
}
strm.next_in = const_cast<unsigned char *>(data);
int ret = 0;
do {
strm.avail_out = BUFSIZE;
strm.next_out = temp_buffer;
ret = inflate(&strm, Z_NO_FLUSH);
buffer += string(reinterpret_cast<unsigned char *>(temp_buffer), BUFSIZE - strm.avail_out);
} while (ret == Z_OK);
if (ret != Z_STREAM_END) {
throw DecompressError();
}
m_seekPos += strm.next_in - data;
(void)inflateEnd(&strm);
return buffer;
}