| /* compress.c -- compress a memory buffer |
| * Copyright (C) 1995-2005 Jean-loup Gailly. |
| * For conditions of distribution and use, see copyright notice in zlib.h |
| */ |
| |
| /* @(#) $Id$ */ |
| |
| #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 ( |
| Bytef *dest, |
| uLongf *destLen, |
| const Bytef *source, |
| uLong sourceLen, |
| int level) |
| { |
| z_stream stream; |
| int err; |
| |
| stream.next_in = (z_const Bytef *)source; |
| stream.avail_in = (uInt)sourceLen; |
| #ifdef MAXSEG_64K |
| /* Check for source > 64K on 16-bit machine: */ |
| if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
| #endif |
| stream.next_out = dest; |
| stream.avail_out = (uInt)*destLen; |
| if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
| |
| stream.zalloc = (alloc_func)0; |
| stream.zfree = (free_func)0; |
| stream.opaque = (voidpf)0; |
| |
| err = deflateInit(&stream, level); |
| if (err != Z_OK) return err; |
| |
| err = deflate(&stream, Z_FINISH); |
| if (err != Z_STREAM_END) { |
| deflateEnd(&stream); |
| return err == Z_OK ? Z_BUF_ERROR : err; |
| } |
| *destLen = stream.total_out; |
| |
| err = deflateEnd(&stream); |
| return err; |
| } |
| |
| /* =========================================================================== |
| */ |
| int ZEXPORT compress ( |
| 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 ( |
| uLong sourceLen) |
| { |
| return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
| (sourceLen >> 25) + 13; |
| } |