diff options
Diffstat (limited to 'libpng/compress.c')
-rw-r--r-- | libpng/compress.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/libpng/compress.c b/libpng/compress.c new file mode 100644 index 0000000..1cee470 --- /dev/null +++ b/libpng/compress.c @@ -0,0 +1,68 @@ +/* compress.c -- compress a memory buffer + * Copyright (C) 1995-1998 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* @(#) $Id$ */ + +#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; + + stream.next_in = (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 (dest, destLen, source, sourceLen) + Bytef *dest; + uLongf *destLen; + const Bytef *source; + uLong sourceLen; +{ + return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); +} |