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76 lines
2.5 KiB
C
76 lines
2.5 KiB
C
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/* uncompr.c -- decompress a memory buffer
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* Copyright (C) 1995-2003, 2010, 2014 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
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size of the destination buffer, which must be large enough to hold the
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entire uncompressed data. (The size of the uncompressed data must have
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been saved previously by the compressor and transmitted to the decompressor
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by some mechanism outside the scope of this compression library.)
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Upon exit, destLen is the actual size of the compressed buffer.
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uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
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enough memory, Z_BUF_ERROR if there was not enough room in the output
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buffer, or Z_DATA_ERROR if the input data was corrupted, including if the
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input data is an incomplete zlib stream.
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*/
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int ZEXPORT uncompress(unsigned char *dest, size_t *destLen, const unsigned char *source, size_t sourceLen) {
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z_stream stream;
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int err;
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const unsigned int max = (unsigned int)0 - 1;
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size_t left;
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unsigned char buf[1]; /* for detection of incomplete stream when *destLen == 0 */
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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 = (const unsigned char *)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 = NULL;
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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 > (unsigned long)max ? max : (unsigned int)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 = sourceLen > (unsigned long)max ? max : (unsigned int)sourceLen;
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sourceLen -= 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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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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