1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25/* uncompr.c -- decompress a memory buffer
26 * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
27 * For conditions of distribution and use, see copyright notice in zlib.h
28 */
29
30/* @(#) $Id$ */
31
32#define ZLIB_INTERNAL
33#include "zlib.h"
34
35/* ===========================================================================
36     Decompresses the source buffer into the destination buffer.  *sourceLen is
37   the byte length of the source buffer. Upon entry, *destLen is the total size
38   of the destination buffer, which must be large enough to hold the entire
39   uncompressed data. (The size of the uncompressed data must have been saved
40   previously by the compressor and transmitted to the decompressor by some
41   mechanism outside the scope of this compression library.) Upon exit,
42   *destLen is the size of the decompressed data and *sourceLen is the number
43   of source bytes consumed. Upon return, source + *sourceLen points to the
44   first unused input byte.
45
46     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
47   memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
48   Z_DATA_ERROR if the input data was corrupted, including if the input data is
49   an incomplete zlib stream.
50*/
51int ZEXPORT uncompress2 (dest, destLen, source, sourceLen)
52    Bytef *dest;
53    uLongf *destLen;
54    const Bytef *source;
55    uLong *sourceLen;
56{
57    z_stream stream;
58    int err;
59    const uInt max = (uInt)-1;
60    uLong len, left;
61    Byte buf[1];    /* for detection of incomplete stream when *destLen == 0 */
62
63    len = *sourceLen;
64    if (*destLen) {
65        left = *destLen;
66        *destLen = 0;
67    }
68    else {
69        left = 1;
70        dest = buf;
71    }
72
73    stream.next_in = (z_const Bytef *)source;
74    stream.avail_in = 0;
75    stream.zalloc = (alloc_func)0;
76    stream.zfree = (free_func)0;
77    stream.opaque = (voidpf)0;
78
79    err = inflateInit(&stream);
80    if (err != Z_OK) return err;
81
82    stream.next_out = dest;
83    stream.avail_out = 0;
84
85    do {
86        if (stream.avail_out == 0) {
87            stream.avail_out = left > (uLong)max ? max : (uInt)left;
88            left -= stream.avail_out;
89        }
90        if (stream.avail_in == 0) {
91            stream.avail_in = len > (uLong)max ? max : (uInt)len;
92            len -= stream.avail_in;
93        }
94        err = inflate(&stream, Z_NO_FLUSH);
95    } while (err == Z_OK);
96
97    *sourceLen -= len + stream.avail_in;
98    if (dest != buf)
99        *destLen = stream.total_out;
100    else if (stream.total_out && err == Z_BUF_ERROR)
101        left = 1;
102
103    inflateEnd(&stream);
104    return err == Z_STREAM_END ? Z_OK :
105           err == Z_NEED_DICT ? Z_DATA_ERROR  :
106           err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
107           err;
108}
109
110int ZEXPORT uncompress (dest, destLen, source, sourceLen)
111    Bytef *dest;
112    uLongf *destLen;
113    const Bytef *source;
114    uLong sourceLen;
115{
116    return uncompress2(dest, destLen, source, &sourceLen);
117}
118