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/* $Id$ */
/*
* (C) Copyright 2011 Bartosz Brachaczek <b.brachaczek@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License Version
* 2.1 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307,
* USA.
*/
/**
* \file deflate.c
*
* \brief Funkcje kompresji Deflate
*/
#ifndef _WIN64
#define _USE_32BIT_TIME_T
#endif
#ifdef _WIN32
#include "win32.h"
#endif /* _WIN32 */
#include <stdlib.h>
#include <string.h>
#include "libgadu.h"
#include "deflate.h"
#ifdef GG_CONFIG_HAVE_ZLIB
#include <zlib.h>
#endif
/**
* \internal Kompresuje dane wejściowe algorytmem Deflate z najwyższym
* stopniem kompresji, tak samo jak oryginalny klient.
*
* Wynik funkcji należy zwolnić za pomocą \c free.
*
* \param in Ciąg znaków do skompresowania, zakończony \c \\0
* \param out_lenp Wskaźnik na zmienną, do której zostanie zapisana
* długość bufora wynikowego
*
* \return Skompresowany ciąg znaków lub \c NULL w przypadku niepowodzenia.
*/
unsigned char *gg_deflate(const char *in, size_t *out_lenp)
{
#ifdef GG_CONFIG_HAVE_ZLIB
int ret;
z_stream strm;
unsigned char *out, *out2;
size_t out_len;
if (in == NULL || out_lenp == NULL)
return NULL;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = strlen(in);
strm.next_in = (unsigned char*) in;
ret = deflateInit(&strm, Z_BEST_COMPRESSION);
if (ret != Z_OK) {
gg_debug(GG_DEBUG_MISC, "// gg_deflate() deflateInit() failed (%d)\n", ret);
return NULL;
}
out_len = deflateBound(&strm, strm.avail_in);
out = (unsigned char*)malloc(out_len);
if (out == NULL) {
gg_debug(GG_DEBUG_MISC, "// gg_deflate() not enough memory for output data (%d)\n", out_len);
goto fail;
}
strm.avail_out = out_len;
strm.next_out = out;
for (;;) {
ret = deflate(&strm, Z_FINISH);
if (ret == Z_STREAM_END)
break;
/* raczej nie powinno się zdarzyć przy Z_FINISH i out_len == deflateBound(),
* ale dokumentacja zlib nie wyklucza takiej możliwości */
if (ret == Z_OK) {
out_len *= 2;
out2 = (unsigned char*)realloc(out, out_len);
if (out2 == NULL) {
gg_debug(GG_DEBUG_MISC, "// gg_deflate() not enough memory for output data (%d)\n", out_len);
goto fail;
}
out = out2;
strm.avail_out = out_len / 2;
strm.next_out = out + out_len / 2;
} else {
gg_debug(GG_DEBUG_MISC, "// gg_deflate() deflate() failed (ret=%d, msg=%s)\n", ret, strm.msg != NULL ? strm.msg : "no error message provided");
goto fail;
}
}
out_len = strm.total_out;
out2 = (unsigned char*)realloc(out, out_len);
if (out2 == NULL) {
gg_debug(GG_DEBUG_MISC, "// gg_deflate() not enough memory for output data (%d)\n", out_len);
goto fail;
}
*out_lenp = out_len;
deflateEnd(&strm);
return out2;
fail:
*out_lenp = 0;
deflateEnd(&strm);
free(out);
#endif
return NULL;
}
/**
* \internal Dekompresuje dane wejściowe w formacie Deflate.
*
* Wynik funkcji należy zwolnić za pomocą \c free.
*
* \param in Bufor danych skompresowanych algorytmem Deflate
* \param length Długość bufora wejściowego
*
* \note Dokleja \c \\0 na końcu bufora wynikowego.
*
* \return Zdekompresowany ciąg znaków, zakończony \c \\0,
* lub \c NULL w przypadku niepowodzenia.
*/
char *gg_inflate(const unsigned char *in, size_t length)
{
#ifdef GG_CONFIG_HAVE_ZLIB
int ret;
z_stream strm;
char *out = NULL, *out2;
size_t out_len = 1024;
int first = 1;
if (in == NULL)
return NULL;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = length;
strm.next_in = (unsigned char*) in;
ret = inflateInit(&strm);
if (ret != Z_OK) {
gg_debug(GG_DEBUG_MISC, "// gg_inflate() inflateInit() failed (%d)\n", ret);
return NULL;
}
do {
out_len *= 2;
out2 = (char*)realloc(out, out_len);
if (out2 == NULL) {
gg_debug(GG_DEBUG_MISC, "// gg_inflate() not enough memory for output data (%d)\n", out_len);
goto fail;
}
out = out2;
if (first) {
strm.avail_out = out_len;
strm.next_out = (unsigned char*) out;
} else {
strm.avail_out = out_len / 2;
strm.next_out = (unsigned char*) out + out_len / 2;
}
ret = inflate(&strm, Z_NO_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END) {
gg_debug(GG_DEBUG_MISC, "// gg_inflate() inflate() failed (ret=%d, msg=%s)\n", ret, strm.msg != NULL ? strm.msg : "no error message provided");
goto fail;
}
first = 0;
} while (ret != Z_STREAM_END);
/* rezerwujemy ostatni znak na NULL-a */
out_len = strm.total_out + 1;
out2 = (char*)realloc(out, out_len);
if (out2 == NULL) {
gg_debug(GG_DEBUG_MISC, "// gg_inflate() not enough memory for output data (%d)\n", out_len);
goto fail;
}
out = out2;
out[out_len - 1] = '\0';
inflateEnd(&strm);
return out;
fail:
inflateEnd(&strm);
free(out);
#endif
return NULL;
}
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