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Add zlib LICENSE file to zlib subdir
author Michael Pavone <pavone@retrodev.com>
date Sun, 15 Jun 2025 15:41:38 -0700
parents 9ef72ee5c0b0
children
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1 /* compress.c -- compress a memory buffer
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2 * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
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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 #define ZLIB_INTERNAL
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9 #include "zlib.h"
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10
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11 /* ===========================================================================
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12 Compresses the source buffer into the destination buffer. The level
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13 parameter has the same meaning as in deflateInit. sourceLen is the byte
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14 length of the source buffer. Upon entry, destLen is the total size of the
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15 destination buffer, which must be at least 0.1% larger than sourceLen plus
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16 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
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17
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18 compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
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19 memory, Z_BUF_ERROR if there was not enough room in the output buffer,
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20 Z_STREAM_ERROR if the level parameter is invalid.
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21 */
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22 int ZEXPORT compress2(Bytef *dest, uLongf *destLen, const Bytef *source,
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23 uLong sourceLen, int level) {
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24 z_stream stream;
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25 int err;
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26 const uInt max = (uInt)-1;
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27 uLong left;
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28
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29 left = *destLen;
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30 *destLen = 0;
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31
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32 stream.zalloc = (alloc_func)0;
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33 stream.zfree = (free_func)0;
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34 stream.opaque = (voidpf)0;
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35
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36 err = deflateInit(&stream, level);
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37 if (err != Z_OK) return err;
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38
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39 stream.next_out = dest;
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40 stream.avail_out = 0;
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41 stream.next_in = (z_const Bytef *)source;
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42 stream.avail_in = 0;
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43
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44 do {
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45 if (stream.avail_out == 0) {
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46 stream.avail_out = left > (uLong)max ? max : (uInt)left;
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47 left -= stream.avail_out;
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48 }
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49 if (stream.avail_in == 0) {
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50 stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
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51 sourceLen -= stream.avail_in;
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52 }
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53 err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
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54 } while (err == Z_OK);
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55
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56 *destLen = stream.total_out;
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57 deflateEnd(&stream);
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58 return err == Z_STREAM_END ? Z_OK : err;
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59 }
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60
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61 /* ===========================================================================
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62 */
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63 int ZEXPORT compress(Bytef *dest, uLongf *destLen, const Bytef *source,
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64 uLong sourceLen) {
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65 return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
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66 }
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67
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68 /* ===========================================================================
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69 If the default memLevel or windowBits for deflateInit() is changed, then
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70 this function needs to be updated.
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71 */
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72 uLong ZEXPORT compressBound(uLong sourceLen) {
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73 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
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74 (sourceLen >> 25) + 13;
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75 }