| 1 | /* uncompr.c -- decompress a memory buffer |
| 2 | * Copyright (C) 1995-2003 Jean-loup Gailly. |
| 3 | * For conditions of distribution and use, see copyright notice in zlib.h |
| 4 | */ |
| 5 | |
| 6 | /* @(#) $Id$ */ |
| 7 | |
| 8 | #define ZLIB_INTERNAL |
| 9 | #include "zlib.h" |
| 10 | |
| 11 | /* =========================================================================== |
| 12 | Decompresses the source buffer into the destination buffer. sourceLen is |
| 13 | the byte length of the source buffer. Upon entry, destLen is the total |
| 14 | size of the destination buffer, which must be large enough to hold the |
| 15 | entire uncompressed data. (The size of the uncompressed data must have |
| 16 | been saved previously by the compressor and transmitted to the decompressor |
| 17 | by some mechanism outside the scope of this compression library.) |
| 18 | Upon exit, destLen is the actual size of the compressed buffer. |
| 19 | This function can be used to decompress a whole file at once if the |
| 20 | input file is mmap'ed. |
| 21 | |
| 22 | uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
| 23 | enough memory, Z_BUF_ERROR if there was not enough room in the output |
| 24 | buffer, or Z_DATA_ERROR if the input data was corrupted. |
| 25 | */ |
| 26 | int ZEXPORT uncompress (dest, destLen, source, sourceLen) |
| 27 | Bytef *dest; |
| 28 | uLongf *destLen; |
| 29 | const Bytef *source; |
| 30 | uLong sourceLen; |
| 31 | { |
| 32 | z_stream stream; |
| 33 | int err; |
| 34 | |
| 35 | stream.next_in = (Bytef*)source; |
| 36 | stream.avail_in = (uInt)sourceLen; |
| 37 | /* Check for source > 64K on 16-bit machine: */ |
| 38 | if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
| 39 | |
| 40 | stream.next_out = dest; |
| 41 | stream.avail_out = (uInt)*destLen; |
| 42 | if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
| 43 | |
| 44 | stream.zalloc = (alloc_func)0; |
| 45 | stream.zfree = (free_func)0; |
| 46 | |
| 47 | err = inflateInit(&stream); |
| 48 | if (err != Z_OK) return err; |
| 49 | |
| 50 | err = inflate(&stream, Z_FINISH); |
| 51 | if (err != Z_STREAM_END) { |
| 52 | inflateEnd(&stream); |
| 53 | if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) |
| 54 | return Z_DATA_ERROR; |
| 55 | return err; |
| 56 | } |
| 57 | *destLen = stream.total_out; |
| 58 | |
| 59 | err = inflateEnd(&stream); |
| 60 | return err; |
| 61 | } |