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 * Read-only access to Zip archives, with minimal heap allocation. 19 * 20 * This is similar to the more-complete ZipFile class, but no attempt 21 * has been made to make them interchangeable. This class operates under 22 * a very different set of assumptions and constraints. 23 * 24 * One such assumption is that if you're getting file descriptors for 25 * use with this class as a child of a fork() operation, you must be on 26 * a pread() to guarantee correct operation. This is because pread() can 27 * atomically read at a file offset without worrying about a lock around an 28 * lseek() + read() pair. 29 */ 30 #ifndef __LIBS_ZIPFILERO_H 31 #define __LIBS_ZIPFILERO_H 32 33 #include <utils/Compat.h> 34 #include <utils/Errors.h> 35 #include <utils/FileMap.h> 36 #include <utils/threads.h> 37 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <unistd.h> 41 #include <time.h> 42 43 typedef void* ZipArchiveHandle; 44 45 namespace android { 46 47 /* 48 * Trivial typedef to ensure that ZipEntryRO is not treated as a simple 49 * integer. We use NULL to indicate an invalid value. 50 */ 51 typedef void* ZipEntryRO; 52 53 /* 54 * Open a Zip archive for reading. 55 * 56 * Implemented as a thin wrapper over system/core/libziparchive. 57 * 58 * "open" and "find entry by name" are fast operations and use as little 59 * memory as possible. 60 * 61 * We also support fast iteration over all entries in the file (with a 62 * stable, but unspecified iteration order). 63 * 64 * NOTE: If this is used on file descriptors inherited from a fork() operation, 65 * you must be on a platform that implements pread() to guarantee correctness 66 * on the shared file descriptors. 67 */ 68 class ZipFileRO { 69 public: 70 /* Zip compression methods we support */ 71 enum { 72 kCompressStored = 0, // no compression 73 kCompressDeflated = 8, // standard deflate 74 }; 75 76 /* 77 * Open an archive. 78 */ 79 static ZipFileRO* open(const char* zipFileName); 80 81 /* 82 * Find an entry, by name. Returns the entry identifier, or NULL if 83 * not found. 84 */ 85 ZipEntryRO findEntryByName(const char* entryName) const; 86 87 88 /* 89 * Start iterating over the list of entries in the zip file. Requires 90 * a matching call to endIteration with the same cookie. 91 */ 92 bool startIteration(void** cookie); 93 94 /** 95 * Return the next entry in iteration order, or NULL if there are no more 96 * entries in this archive. 97 */ 98 ZipEntryRO nextEntry(void* cookie); 99 100 void endIteration(void* cookie); 101 102 void releaseEntry(ZipEntryRO entry) const; 103 104 /* 105 * Return the #of entries in the Zip archive. 106 */ 107 int getNumEntries(); 108 109 /* 110 * Copy the filename into the supplied buffer. Returns 0 on success, 111 * -1 if "entry" is invalid, or the filename length if it didn't fit. The 112 * length, and the returned string, include the null-termination. 113 */ 114 int getEntryFileName(ZipEntryRO entry, char* buffer, int bufLen) const; 115 116 /* 117 * Get the vital stats for an entry. Pass in NULL pointers for anything 118 * you don't need. 119 * 120 * "*pOffset" holds the Zip file offset of the entry's data. 121 * 122 * Returns "false" if "entry" is bogus or if the data in the Zip file 123 * appears to be bad. 124 */ 125 bool getEntryInfo(ZipEntryRO entry, int* pMethod, size_t* pUncompLen, 126 size_t* pCompLen, off64_t* pOffset, long* pModWhen, long* pCrc32) const; 127 128 /* 129 * Create a new FileMap object that maps a subset of the archive. For 130 * an uncompressed entry this effectively provides a pointer to the 131 * actual data, for a compressed entry this provides the input buffer 132 * for inflate(). 133 */ 134 FileMap* createEntryFileMap(ZipEntryRO entry) const; 135 136 /* 137 * Uncompress the data into a buffer. Depending on the compression 138 * format, this is either an "inflate" operation or a memcpy. 139 * 140 * Use "uncompLen" from getEntryInfo() to determine the required 141 * buffer size. 142 * 143 * Returns "true" on success. 144 */ 145 bool uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const; 146 147 /* 148 * Uncompress the data to an open file descriptor. 149 */ 150 bool uncompressEntry(ZipEntryRO entry, int fd) const; 151 152 ~ZipFileRO(); 153 154 private: 155 /* these are private and not defined */ 156 ZipFileRO(const ZipFileRO& src); 157 ZipFileRO& operator=(const ZipFileRO& src); 158 159 ZipFileRO(ZipArchiveHandle handle, char* fileName) : mHandle(handle), 160 mFileName(fileName) 161 { 162 } 163 164 const ZipArchiveHandle mHandle; 165 char* mFileName; 166 }; 167 168 }; // namespace android 169 170 #endif /*__LIBS_ZIPFILERO_H*/ 171
