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 <stdint.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <unistd.h> 42 #include <time.h> 43 44 typedef void* ZipArchiveHandle; 45 46 namespace android { 47 48 /* 49 * Trivial typedef to ensure that ZipEntryRO is not treated as a simple 50 * integer. We use NULL to indicate an invalid value. 51 */ 52 typedef void* ZipEntryRO; 53 54 /* 55 * Open a Zip archive for reading. 56 * 57 * Implemented as a thin wrapper over system/core/libziparchive. 58 * 59 * "open" and "find entry by name" are fast operations and use as little 60 * memory as possible. 61 * 62 * We also support fast iteration over all entries in the file (with a 63 * stable, but unspecified iteration order). 64 * 65 * NOTE: If this is used on file descriptors inherited from a fork() operation, 66 * you must be on a platform that implements pread() to guarantee correctness 67 * on the shared file descriptors. 68 */ 69 class ZipFileRO { 70 public: 71 /* Zip compression methods we support */ 72 enum : uint16_t { 73 kCompressStored = 0, 74 kCompressDeflated = 8 75 }; 76 77 /* 78 * Open an archive. 79 */ 80 static ZipFileRO* open(const char* zipFileName); 81 82 /* 83 * Find an entry, by name. Returns the entry identifier, or NULL if 84 * not found. 85 */ 86 ZipEntryRO findEntryByName(const char* entryName) const; 87 88 89 /* 90 * Start iterating over the list of entries in the zip file. Requires 91 * a matching call to endIteration with the same cookie. 92 */ 93 bool startIteration(void** cookie); 94 bool startIteration(void** cookie, const char* prefix, const char* suffix); 95 96 /** 97 * Return the next entry in iteration order, or NULL if there are no more 98 * entries in this archive. 99 */ 100 ZipEntryRO nextEntry(void* cookie); 101 102 void endIteration(void* cookie); 103 104 void releaseEntry(ZipEntryRO entry) const; 105 106 /* 107 * Return the #of entries in the Zip archive. 108 */ 109 int getNumEntries(); 110 111 /* 112 * Copy the filename into the supplied buffer. Returns 0 on success, 113 * -1 if "entry" is invalid, or the filename length if it didn't fit. The 114 * length, and the returned string, include the null-termination. 115 */ 116 int getEntryFileName(ZipEntryRO entry, char* buffer, size_t bufLen) const; 117 118 /* 119 * Get the vital stats for an entry. Pass in NULL pointers for anything 120 * you don't need. 121 * 122 * "*pOffset" holds the Zip file offset of the entry's data. 123 * 124 * Returns "false" if "entry" is bogus or if the data in the Zip file 125 * appears to be bad. 126 */ 127 bool getEntryInfo(ZipEntryRO entry, uint16_t* pMethod, uint32_t* pUncompLen, 128 uint32_t* pCompLen, off64_t* pOffset, uint32_t* pModWhen, 129 uint32_t* pCrc32) const; 130 131 /* 132 * Create a new FileMap object that maps a subset of the archive. For 133 * an uncompressed entry this effectively provides a pointer to the 134 * actual data, for a compressed entry this provides the input buffer 135 * for inflate(). 136 */ 137 FileMap* createEntryFileMap(ZipEntryRO entry) const; 138 139 /* 140 * Uncompress the data into a buffer. Depending on the compression 141 * format, this is either an "inflate" operation or a memcpy. 142 * 143 * Use "uncompLen" from getEntryInfo() to determine the required 144 * buffer size. 145 * 146 * Returns "true" on success. 147 */ 148 bool uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const; 149 150 /* 151 * Uncompress the data to an open file descriptor. 152 */ 153 bool uncompressEntry(ZipEntryRO entry, int fd) const; 154 155 ~ZipFileRO(); 156 157 private: 158 /* these are private and not defined */ 159 ZipFileRO(const ZipFileRO& src); 160 ZipFileRO& operator=(const ZipFileRO& src); 161 ZipFileRO(ZipArchiveHandle handle,char * fileName)162 ZipFileRO(ZipArchiveHandle handle, char* fileName) : mHandle(handle), 163 mFileName(fileName) 164 { 165 } 166 167 const ZipArchiveHandle mHandle; 168 char* mFileName; 169 }; 170 171 }; // namespace android 172 173 #endif /*__LIBS_ZIPFILERO_H*/ 174