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1 /* compress.c -- compress 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 Compresses the source buffer into the destination buffer. The level
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12 parameter has the same meaning as in deflateInit. sourceLen is the byte
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13 length of the source buffer. Upon entry, destLen is the total size of the
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14 destination buffer, which must be at least 0.1% larger than sourceLen plus
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15 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
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16
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17 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
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18 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
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19 Z_STREAM_ERROR if the level parameter is invalid.
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20 */
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21 int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
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22 Bytef *dest;
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23 uLongf *destLen;
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24 const Bytef *source;
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25 uLong sourceLen;
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26 int level;
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27 {
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28 z_stream stream;
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29 int err;
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30
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31 stream.next_in = (Bytef*)source;
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32 stream.avail_in = (uInt)sourceLen;
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33 #ifdef MAXSEG_64K
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34 /* Check for source > 64K on 16-bit machine: */
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35 if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
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36 #endif
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37 stream.next_out = dest;
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38 stream.avail_out = (uInt)*destLen;
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39 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
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40
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41 stream.zalloc = (alloc_func)0;
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42 stream.zfree = (free_func)0;
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43 stream.opaque = (voidpf)0;
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44
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45 err = deflateInit(&stream, level);
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46 if (err != Z_OK) return err;
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47
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48 err = deflate(&stream, Z_FINISH);
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49 if (err != Z_STREAM_END) {
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50 deflateEnd(&stream);
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51 return err == Z_OK ? Z_BUF_ERROR : err;
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52 }
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53 *destLen = stream.total_out;
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54
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55 err = deflateEnd(&stream);
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56 return err;
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57 }
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58
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59 /* ===========================================================================
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60 */
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61 int ZEXPORT compress (dest, destLen, source, sourceLen)
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62 Bytef *dest;
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63 uLongf *destLen;
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64 const Bytef *source;
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65 uLong sourceLen;
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66 {
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67 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
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68 }
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