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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 
25 namespace android {
26 
27 /*
28  * Container class for utility functions, primarily for namespace reasons.
29  */
30 class ZipUtils {
31 public:
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 
60 private:
ZipUtils()61     ZipUtils() {}
~ZipUtils()62     ~ZipUtils() {}
63 };
64 
65 }; // namespace android
66 
67 #endif /*__LIBS_ZIPUTILS_H*/
68