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 struct ZipArchive; 45 typedef ZipArchive* ZipArchiveHandle; 46 47 namespace android { 48 49 /* 50 * Trivial typedef to ensure that ZipEntryRO is not treated as a simple 51 * integer. We use NULL to indicate an invalid value. 52 */ 53 typedef void* ZipEntryRO; 54 55 /* 56 * Open a Zip archive for reading. 57 * 58 * Implemented as a thin wrapper over system/core/libziparchive. 59 * 60 * "open" and "find entry by name" are fast operations and use as little 61 * memory as possible. 62 * 63 * We also support fast iteration over all entries in the file (with a 64 * stable, but unspecified iteration order). 65 * 66 * NOTE: If this is used on file descriptors inherited from a fork() operation, 67 * you must be on a platform that implements pread() to guarantee correctness 68 * on the shared file descriptors. 69 */ 70 class ZipFileRO { 71 public: 72 /* Zip compression methods we support */ 73 enum : uint16_t { 74 kCompressStored = 0, 75 kCompressDeflated = 8 76 }; 77 78 /* 79 * Open an archive. 80 */ 81 static ZipFileRO* open(const char* zipFileName); 82 83 /* 84 * Open an archive from an already open file descriptor. 85 */ 86 static ZipFileRO* openFd(int fd, const char* debugFileName, 87 bool assume_ownership = true); 88 89 /* 90 * Find an entry, by name. Returns the entry identifier, or NULL if 91 * not found. 92 */ 93 ZipEntryRO findEntryByName(const char* entryName) const; 94 95 96 /* 97 * Start iterating over the list of entries in the zip file. Requires 98 * a matching call to endIteration with the same cookie. 99 */ 100 bool startIteration(void** cookie); 101 bool startIteration(void** cookie, const char* prefix, const char* suffix); 102 103 /** 104 * Return the next entry in iteration order, or NULL if there are no more 105 * entries in this archive. 106 */ 107 ZipEntryRO nextEntry(void* cookie); 108 109 void endIteration(void* cookie); 110 111 void releaseEntry(ZipEntryRO entry) const; 112 113 /* 114 * Return the #of entries in the Zip archive. 115 */ 116 int getNumEntries(); 117 118 /* 119 * Copy the filename into the supplied buffer. Returns 0 on success, 120 * -1 if "entry" is invalid, or the filename length if it didn't fit. The 121 * length, and the returned string, include the null-termination. 122 */ 123 int getEntryFileName(ZipEntryRO entry, char* buffer, size_t bufLen) const; 124 125 /* 126 * Get the vital stats for an entry. Pass in NULL pointers for anything 127 * you don't need. 128 * 129 * "*pOffset" holds the Zip file offset of the entry's data. 130 * 131 * Returns "false" if "entry" is bogus or if the data in the Zip file 132 * appears to be bad. 133 */ 134 bool getEntryInfo(ZipEntryRO entry, uint16_t* pMethod, uint32_t* pUncompLen, 135 uint32_t* pCompLen, off64_t* pOffset, uint32_t* pModWhen, 136 uint32_t* pCrc32) const; 137 138 /* 139 * Create a new FileMap object that maps a subset of the archive. For 140 * an uncompressed entry this effectively provides a pointer to the 141 * actual data, for a compressed entry this provides the input buffer 142 * for inflate(). 143 */ 144 FileMap* createEntryFileMap(ZipEntryRO entry) const; 145 146 /* 147 * Uncompress the data into a buffer. Depending on the compression 148 * format, this is either an "inflate" operation or a memcpy. 149 * 150 * Use "uncompLen" from getEntryInfo() to determine the required 151 * buffer size. 152 * 153 * Returns "true" on success. 154 */ 155 bool uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const; 156 157 /* 158 * Uncompress the data to an open file descriptor. 159 */ 160 bool uncompressEntry(ZipEntryRO entry, int fd) const; 161 162 ~ZipFileRO(); 163 164 private: 165 /* these are private and not defined */ 166 ZipFileRO(const ZipFileRO& src); 167 ZipFileRO& operator=(const ZipFileRO& src); 168 ZipFileRO(ZipArchiveHandle handle,char * fileName)169 ZipFileRO(ZipArchiveHandle handle, char* fileName) : mHandle(handle), 170 mFileName(fileName) 171 { 172 } 173 174 const ZipArchiveHandle mHandle; 175 char* mFileName; 176 }; 177 178 }; // namespace android 179 180 #endif /*__LIBS_ZIPFILERO_H*/ 181