ZipUtils.h revision 1f5762e646bed2290934280464832782766ee68e
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17//
18// Miscellaneous zip/gzip utility functions.
19//
20#ifndef __LIBS_ZIPUTILS_H
21#define __LIBS_ZIPUTILS_H
22
23#include <stdio.h>
24
25namespace android {
26
27/*
28 * Container class for utility functions, primarily for namespace reasons.
29 */
30class ZipUtils {
31public:
32    /*
33     * General utility function for uncompressing "deflate" data from a file
34     * to a buffer.
35     */
36    static bool inflateToBuffer(int fd, void* buf, long uncompressedLen,
37        long compressedLen);
38    static bool inflateToBuffer(FILE* fp, void* buf, long uncompressedLen,
39        long compressedLen);
40
41    /*
42     * Someday we might want to make this generic and handle bzip2 ".bz2"
43     * files too.
44     *
45     * We could declare gzip to be a sub-class of zip that has exactly
46     * one always-compressed entry, but we currently want to treat Zip
47     * and gzip as distinct, so there's no value.
48     *
49     * The zlib library has some gzip utilities, but it has no interface
50     * for extracting the uncompressed length of the file (you do *not*
51     * want to gzseek to the end).
52     *
53     * Pass in a seeked file pointer for the gzip file.  If this is a gzip
54     * file, we set our return values appropriately and return "true" with
55     * the file seeked to the start of the compressed data.
56     */
57    static bool examineGzip(FILE* fp, int* pCompressionMethod,
58        long* pUncompressedLen, long* pCompressedLen, unsigned long* pCRC32);
59
60private:
61    ZipUtils() {}
62    ~ZipUtils() {}
63};
64
65}; // namespace android
66
67#endif /*__LIBS_ZIPUTILS_H*/
68