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1 /* uncompr.c -- decompress a memory buffer
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2 * Copyright (C) 1995-1998 Jean-loup Gailly.
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3 * For conditions of distribution and use, see copyright notice in zlib.h
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4 */
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5
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6 /* @(#) $Id$ */
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7
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8 #include "zlib.h"
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9
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10 /* ===========================================================================
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11 Decompresses the source buffer into the destination buffer. sourceLen is
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12 the byte length of the source buffer. Upon entry, destLen is the total
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13 size of the destination buffer, which must be large enough to hold the
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14 entire uncompressed data. (The size of the uncompressed data must have
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15 been saved previously by the compressor and transmitted to the decompressor
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16 by some mechanism outside the scope of this compression library.)
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17 Upon exit, destLen is the actual size of the compressed buffer.
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18 This function can be used to decompress a whole file at once if the
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19 input file is mmap'ed.
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20
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21 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
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22 enough memory, Z_BUF_ERROR if there was not enough room in the output
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23 buffer, or Z_DATA_ERROR if the input data was corrupted.
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24 */
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25 int ZEXPORT uncompress (dest, destLen, source, sourceLen)
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26 Bytef *dest;
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27 uLongf *destLen;
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28 const Bytef *source;
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29 uLong sourceLen;
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30 {
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31 z_stream stream;
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32 int err;
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33
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34 stream.next_in = (Bytef*)source;
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35 stream.avail_in = (uInt)sourceLen;
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36 /* Check for source > 64K on 16-bit machine: */
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37 if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
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38
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39 stream.next_out = dest;
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40 stream.avail_out = (uInt)*destLen;
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41 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
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42
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43 stream.zalloc = (alloc_func)0;
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44 stream.zfree = (free_func)0;
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45
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46 err = inflateInit(&stream);
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47 if (err != Z_OK) return err;
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48
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49 err = inflate(&stream, Z_FINISH);
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50 if (err != Z_STREAM_END) {
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51 inflateEnd(&stream);
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52 return err == Z_OK ? Z_BUF_ERROR : err;
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53 }
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54 *destLen = stream.total_out;
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55
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56 err = inflateEnd(&stream);
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57 return err;
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58 }
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