00001 /* uncompr.c -- decompress a memory buffer 00002 * Copyright (C) 1995-2003 Jean-loup Gailly. 00003 * For conditions of distribution and use, see copyright notice in zlib.h 00004 */ 00005 00006 /* @(#) $Id: uncompr.c,v 1.2 2005/07/18 22:06:08 spooky23 Exp $ */ 00007 00008 #define ZLIB_INTERNAL 00009 #include "zlib.h" 00010 00011 /* =========================================================================== 00012 Decompresses the source buffer into the destination buffer. sourceLen is 00013 the byte length of the source buffer. Upon entry, destLen is the total 00014 size of the destination buffer, which must be large enough to hold the 00015 entire uncompressed data. (The size of the uncompressed data must have 00016 been saved previously by the compressor and transmitted to the decompressor 00017 by some mechanism outside the scope of this compression library.) 00018 Upon exit, destLen is the actual size of the compressed buffer. 00019 This function can be used to decompress a whole file at once if the 00020 input file is mmap'ed. 00021 00022 uncompress returns Z_OK if success, Z_MEM_ERROR if there was not 00023 enough memory, Z_BUF_ERROR if there was not enough room in the output 00024 buffer, or Z_DATA_ERROR if the input data was corrupted. 00025 */ 00026 int ZEXPORT uncompress (dest, destLen, source, sourceLen) 00027 Bytef *dest; 00028 uLongf *destLen; 00029 const Bytef *source; 00030 uLong sourceLen; 00031 { 00032 z_stream stream; 00033 int err; 00034 00035 stream.next_in = (Bytef*)source; 00036 stream.avail_in = (uInt)sourceLen; 00037 /* Check for source > 64K on 16-bit machine: */ 00038 if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; 00039 00040 stream.next_out = dest; 00041 stream.avail_out = (uInt)*destLen; 00042 if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; 00043 00044 stream.zalloc = (alloc_func)0; 00045 stream.zfree = (free_func)0; 00046 00047 err = inflateInit(&stream); 00048 if (err != Z_OK) return err; 00049 00050 err = inflate(&stream, Z_FINISH); 00051 if (err != Z_STREAM_END) { 00052 inflateEnd(&stream); 00053 if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) 00054 return Z_DATA_ERROR; 00055 return err; 00056 } 00057 *destLen = stream.total_out; 00058 00059 err = inflateEnd(&stream); 00060 return err; 00061 }