de1ab01e8e
Changes in 1.2.10 (2 Jan 2017) - Avoid warnings on snprintf() return value - Fix bug in deflate_stored() for zero-length input - Fix bug in gzwrite.c that produced corrupt gzip files - Remove files to be installed before copying them in Makefile.in - Add warnings when compiling with assembler code Changes in 1.2.9 (31 Dec 2016) - Fix contrib/minizip to permit unzipping with desktop API [Zouzou] - Improve contrib/blast to return unused bytes - Assure that gzoffset() is correct when appending - Improve compress() and uncompress() to support large lengths - Fix bug in test/example.c where error code not saved - Remedy Coverity warning [Randers-Pehrson] - Improve speed of gzprintf() in transparent mode - Fix inflateInit2() bug when windowBits is 16 or 32 - Change DEBUG macro to ZLIB_DEBUG - Avoid uninitialized access by gzclose_w() - Allow building zlib outside of the source directory - Fix bug that accepted invalid zlib header when windowBits is zero - Fix gzseek() problem on MinGW due to buggy _lseeki64 there - Loop on write() calls in gzwrite.c in case of non-blocking I/O - Add --warn (-w) option to ./configure for more compiler warnings - Reject a window size of 256 bytes if not using the zlib wrapper - Fix bug when level 0 used with Z_HUFFMAN or Z_RLE - Add --debug (-d) option to ./configure to define ZLIB_DEBUG - Fix bugs in creating a very large gzip header - Add uncompress2() function, which returns the input size used - Assure that deflateParams() will not switch functions mid-block - Dramatically speed up deflation for level 0 (storing) - Add gzfread(), duplicating the interface of fread() - Add gzfwrite(), duplicating the interface of fwrite() - Add deflateGetDictionary() function - Use snprintf() for later versions of Microsoft C - Fix *Init macros to use z_ prefix when requested - Replace as400 with os400 for OS/400 support [Monnerat] - Add crc32_z() and adler32_z() functions with size_t lengths - Update Visual Studio project files [AraHaan]
87 lines
2.7 KiB
C
87 lines
2.7 KiB
C
/* compress.c -- compress a memory buffer
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* Copyright (C) 1995-2005, 2014, 2016 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: compress.c,v 1.1.1.2 2002/03/11 21:53:23 tromey Exp $ */
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#define ZLIB_INTERNAL
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#include "zlib.h"
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/* ===========================================================================
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Compresses the source buffer into the destination buffer. The level
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parameter has the same meaning as in deflateInit. sourceLen is the byte
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length of the source buffer. Upon entry, destLen is the total size of the
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destination buffer, which must be at least 0.1% larger than sourceLen plus
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12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
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compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
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memory, Z_BUF_ERROR if there was not enough room in the output buffer,
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Z_STREAM_ERROR if the level parameter is invalid.
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*/
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int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
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Bytef *dest;
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uLongf *destLen;
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const Bytef *source;
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uLong sourceLen;
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int level;
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{
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z_stream stream;
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int err;
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const uInt max = (uInt)-1;
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uLong left;
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left = *destLen;
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*destLen = 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 = (voidpf)0;
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err = deflateInit(&stream, level);
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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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stream.next_in = (z_const Bytef *)source;
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stream.avail_in = 0;
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do {
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if (stream.avail_out == 0) {
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stream.avail_out = left > (uLong)max ? max : (uInt)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 > (uLong)max ? max : (uInt)sourceLen;
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sourceLen -= stream.avail_in;
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}
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err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
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} while (err == Z_OK);
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*destLen = stream.total_out;
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deflateEnd(&stream);
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return err == Z_STREAM_END ? Z_OK : err;
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}
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/* ===========================================================================
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*/
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int ZEXPORT compress (dest, destLen, source, sourceLen)
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Bytef *dest;
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uLongf *destLen;
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const Bytef *source;
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uLong sourceLen;
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{
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return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
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}
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/* ===========================================================================
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If the default memLevel or windowBits for deflateInit() is changed, then
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this function needs to be updated.
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*/
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uLong ZEXPORT compressBound (sourceLen)
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uLong sourceLen;
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{
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return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
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(sourceLen >> 25) + 13;
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}
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