| 1 | /* uncompr.c -- decompress a memory buffer
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| 2 | * Copyright (C) 1995-2003 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 "zutil.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 = 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 | if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
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| 53 | return Z_DATA_ERROR;
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| 54 | return err;
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| 55 | }
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| 56 | *destLen = stream.total_out;
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| 57 |
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| 58 | err = inflateEnd(&stream);
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| 59 | return err;
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| 60 | }
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