michael@0: /* compress.c -- compress a memory buffer
michael@0:  * Copyright (C) 1995-2005 Jean-loup Gailly.
michael@0:  * For conditions of distribution and use, see copyright notice in zlib.h
michael@0:  */
michael@0: 
michael@0: /* @(#) $Id$ */
michael@0: 
michael@0: #define ZLIB_INTERNAL
michael@0: #include "zlib.h"
michael@0: 
michael@0: /* ===========================================================================
michael@0:      Compresses the source buffer into the destination buffer. The level
michael@0:    parameter has the same meaning as in deflateInit.  sourceLen is the byte
michael@0:    length of the source buffer. Upon entry, destLen is the total size of the
michael@0:    destination buffer, which must be at least 0.1% larger than sourceLen plus
michael@0:    12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
michael@0: 
michael@0:      compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
michael@0:    memory, Z_BUF_ERROR if there was not enough room in the output buffer,
michael@0:    Z_STREAM_ERROR if the level parameter is invalid.
michael@0: */
michael@0: int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
michael@0:     Bytef *dest;
michael@0:     uLongf *destLen;
michael@0:     const Bytef *source;
michael@0:     uLong sourceLen;
michael@0:     int level;
michael@0: {
michael@0:     z_stream stream;
michael@0:     int err;
michael@0: 
michael@0:     stream.next_in = (Bytef*)source;
michael@0:     stream.avail_in = (uInt)sourceLen;
michael@0: #ifdef MAXSEG_64K
michael@0:     /* Check for source > 64K on 16-bit machine: */
michael@0:     if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
michael@0: #endif
michael@0:     stream.next_out = dest;
michael@0:     stream.avail_out = (uInt)*destLen;
michael@0:     if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
michael@0: 
michael@0:     stream.zalloc = (alloc_func)0;
michael@0:     stream.zfree = (free_func)0;
michael@0:     stream.opaque = (voidpf)0;
michael@0: 
michael@0:     err = deflateInit(&stream, level);
michael@0:     if (err != Z_OK) return err;
michael@0: 
michael@0:     err = deflate(&stream, Z_FINISH);
michael@0:     if (err != Z_STREAM_END) {
michael@0:         deflateEnd(&stream);
michael@0:         return err == Z_OK ? Z_BUF_ERROR : err;
michael@0:     }
michael@0:     *destLen = stream.total_out;
michael@0: 
michael@0:     err = deflateEnd(&stream);
michael@0:     return err;
michael@0: }
michael@0: 
michael@0: /* ===========================================================================
michael@0:  */
michael@0: int ZEXPORT compress (dest, destLen, source, sourceLen)
michael@0:     Bytef *dest;
michael@0:     uLongf *destLen;
michael@0:     const Bytef *source;
michael@0:     uLong sourceLen;
michael@0: {
michael@0:     return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
michael@0: }
michael@0: 
michael@0: /* ===========================================================================
michael@0:      If the default memLevel or windowBits for deflateInit() is changed, then
michael@0:    this function needs to be updated.
michael@0:  */
michael@0: uLong ZEXPORT compressBound (sourceLen)
michael@0:     uLong sourceLen;
michael@0: {
michael@0:     return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
michael@0:            (sourceLen >> 25) + 13;
michael@0: }