0,0 → 1,80 |
/* compress.c -- compress a memory buffer |
* Copyright (C) 1995-2005 Jean-loup Gailly. |
* For conditions of distribution and use, see copyright notice in zlib.h |
*/ |
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/* @(#) $Id$ */ |
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#define ZLIB_INTERNAL |
#include "zlib.h" |
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/* =========================================================================== |
Compresses the source buffer into the destination buffer. The level |
parameter has the same meaning as in deflateInit. sourceLen is the byte |
length of the source buffer. Upon entry, destLen is the total size of the |
destination buffer, which must be at least 0.1% larger than sourceLen plus |
12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
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compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
Z_STREAM_ERROR if the level parameter is invalid. |
*/ |
int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
Bytef *dest; |
uLongf *destLen; |
const Bytef *source; |
uLong sourceLen; |
int level; |
{ |
z_stream stream; |
int err; |
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stream.next_in = (z_const Bytef *)source; |
stream.avail_in = (uInt)sourceLen; |
#ifdef MAXSEG_64K |
/* Check for source > 64K on 16-bit machine: */ |
if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
#endif |
stream.next_out = dest; |
stream.avail_out = (uInt)*destLen; |
if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
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stream.zalloc = (alloc_func)0; |
stream.zfree = (free_func)0; |
stream.opaque = (voidpf)0; |
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err = deflateInit(&stream, level); |
if (err != Z_OK) return err; |
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err = deflate(&stream, Z_FINISH); |
if (err != Z_STREAM_END) { |
deflateEnd(&stream); |
return err == Z_OK ? Z_BUF_ERROR : err; |
} |
*destLen = stream.total_out; |
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err = deflateEnd(&stream); |
return err; |
} |
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/* =========================================================================== |
*/ |
int ZEXPORT compress (dest, destLen, source, sourceLen) |
Bytef *dest; |
uLongf *destLen; |
const Bytef *source; |
uLong sourceLen; |
{ |
return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
} |
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/* =========================================================================== |
If the default memLevel or windowBits for deflateInit() is changed, then |
this function needs to be updated. |
*/ |
uLong ZEXPORT compressBound (sourceLen) |
uLong sourceLen; |
{ |
return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
(sourceLen >> 25) + 13; |
} |