| /* compress.c -- compress a memory buffer |
| * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler |
| * For conditions of distribution and use, see copyright notice in zlib.h |
| */ |
| |
| /* @(#) $Id: compress.c,v 1.1.1.2 2002/03/11 21:53:23 tromey Exp $ */ |
| |
| #define ZLIB_INTERNAL |
| #include "zlib.h" |
| |
| /* =========================================================================== |
| Compresses the source buffer into the destination buffer. The level |
| parameter has the same meaning as in deflateInit. sourceLen is the byte |
| length of the source buffer. Upon entry, destLen is the total size of the |
| destination buffer, which must be at least 0.1% larger than sourceLen plus |
| 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
| |
| compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
| Z_STREAM_ERROR if the level parameter is invalid. |
| */ |
| int ZEXPORT compress2 (dest, destLen, source, sourceLen, level) |
| Bytef *dest; |
| uLongf *destLen; |
| const Bytef *source; |
| uLong sourceLen; |
| int level; |
| { |
| z_stream stream; |
| int err; |
| const uInt max = (uInt)-1; |
| uLong left; |
| |
| left = *destLen; |
| *destLen = 0; |
| |
| stream.zalloc = (alloc_func)0; |
| stream.zfree = (free_func)0; |
| stream.opaque = (voidpf)0; |
| |
| err = deflateInit(&stream, level); |
| if (err != Z_OK) return err; |
| |
| stream.next_out = dest; |
| stream.avail_out = 0; |
| stream.next_in = (z_const Bytef *)source; |
| stream.avail_in = 0; |
| |
| do { |
| if (stream.avail_out == 0) { |
| stream.avail_out = left > (uLong)max ? max : (uInt)left; |
| left -= stream.avail_out; |
| } |
| if (stream.avail_in == 0) { |
| stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen; |
| sourceLen -= stream.avail_in; |
| } |
| err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH); |
| } while (err == Z_OK); |
| |
| *destLen = stream.total_out; |
| deflateEnd(&stream); |
| return err == Z_STREAM_END ? Z_OK : err; |
| } |
| |
| /* =========================================================================== |
| */ |
| int ZEXPORT compress (dest, destLen, source, sourceLen) |
| Bytef *dest; |
| uLongf *destLen; |
| const Bytef *source; |
| uLong sourceLen; |
| { |
| return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
| } |
| |
| /* =========================================================================== |
| If the default memLevel or windowBits for deflateInit() is changed, then |
| this function needs to be updated. |
| */ |
| uLong ZEXPORT compressBound (sourceLen) |
| uLong sourceLen; |
| { |
| return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
| (sourceLen >> 25) + 13; |
| } |