94 lines
2.9 KiB
C
94 lines
2.9 KiB
C
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/* uncompr.c -- decompress a memory buffer
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* Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
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* For conditions of distribution and use, see copyright notice in zlib.h
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*/
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/* @(#) $Id$ */
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#define ZLIB_INTERNAL
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#include "zlib.h"
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/* ===========================================================================
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Decompresses the source buffer into the destination buffer. *sourceLen is
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the byte length of the source buffer. Upon entry, *destLen is the total size
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of the destination buffer, which must be large enough to hold the entire
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uncompressed data. (The size of the uncompressed data must have been saved
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previously by the compressor and transmitted to the decompressor by some
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mechanism outside the scope of this compression library.) Upon exit,
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*destLen is the size of the decompressed data and *sourceLen is the number
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of source bytes consumed. Upon return, source + *sourceLen points to the
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first unused input byte.
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uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
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memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
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Z_DATA_ERROR if the input data was corrupted, including if the input data is
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an incomplete zlib stream.
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*/
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int ZEXPORT uncompress2 (dest, destLen, source, sourceLen)
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Bytef *dest;
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uLongf *destLen;
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const Bytef *source;
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uLong *sourceLen;
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{
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z_stream stream;
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int err;
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const uInt max = (uInt)-1;
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uLong len, left;
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Byte buf[1]; /* for detection of incomplete stream when *destLen == 0 */
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len = *sourceLen;
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if (*destLen) {
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left = *destLen;
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*destLen = 0;
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}
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else {
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left = 1;
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dest = buf;
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}
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stream.next_in = (z_const Bytef *)source;
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stream.avail_in = 0;
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stream.zalloc = (alloc_func)0;
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stream.zfree = (free_func)0;
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stream.opaque = (voidpf)0;
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err = inflateInit(&stream);
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if (err != Z_OK) return err;
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stream.next_out = dest;
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stream.avail_out = 0;
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do {
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if (stream.avail_out == 0) {
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stream.avail_out = left > (uLong)max ? max : (uInt)left;
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left -= stream.avail_out;
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}
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if (stream.avail_in == 0) {
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stream.avail_in = len > (uLong)max ? max : (uInt)len;
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len -= stream.avail_in;
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}
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err = inflate(&stream, Z_NO_FLUSH);
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} while (err == Z_OK);
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*sourceLen -= len + stream.avail_in;
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if (dest != buf)
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*destLen = stream.total_out;
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else if (stream.total_out && err == Z_BUF_ERROR)
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left = 1;
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inflateEnd(&stream);
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return err == Z_STREAM_END ? Z_OK :
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err == Z_NEED_DICT ? Z_DATA_ERROR :
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err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
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err;
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}
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int ZEXPORT uncompress (dest, destLen, source, sourceLen)
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Bytef *dest;
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uLongf *destLen;
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const Bytef *source;
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uLong sourceLen;
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{
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return uncompress2(dest, destLen, source, &sourceLen);
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}
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