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 * Open an archive from an already open file descriptor. 84 */ 85 static ZipFileRO* openFd(int fd, const char* debugFileName, 86 bool assume_ownership = true); 87 88 /* 89 * Find an entry, by name. Returns the entry identifier, or NULL if 90 * not found. 91 */ 92 ZipEntryRO findEntryByName(const char* entryName) const; 93 94 95 /* 96 * Start iterating over the list of entries in the zip file. Requires 97 * a matching call to endIteration with the same cookie. 98 */ 99 bool startIteration(void** cookie); 100 bool startIteration(void** cookie, const char* prefix, const char* suffix); 101 102 /** 103 * Return the next entry in iteration order, or NULL if there are no more 104 * entries in this archive. 105 */ 106 ZipEntryRO nextEntry(void* cookie); 107 108 void endIteration(void* cookie); 109 110 void releaseEntry(ZipEntryRO entry) const; 111 112 /* 113 * Return the #of entries in the Zip archive. 114 */ 115 int getNumEntries(); 116 117 /* 118 * Copy the filename into the supplied buffer. Returns 0 on success, 119 * -1 if "entry" is invalid, or the filename length if it didn't fit. The 120 * length, and the returned string, include the null-termination. 121 */ 122 int getEntryFileName(ZipEntryRO entry, char* buffer, size_t bufLen) const; 123 124 /* 125 * Get the vital stats for an entry. Pass in NULL pointers for anything 126 * you don't need. 127 * 128 * "*pOffset" holds the Zip file offset of the entry's data. 129 * 130 * Returns "false" if "entry" is bogus or if the data in the Zip file 131 * appears to be bad. 132 */ 133 bool getEntryInfo(ZipEntryRO entry, uint16_t* pMethod, uint32_t* pUncompLen, 134 uint32_t* pCompLen, off64_t* pOffset, uint32_t* pModWhen, 135 uint32_t* pCrc32) const; 136 137 /* 138 * Create a new FileMap object that maps a subset of the archive. For 139 * an uncompressed entry this effectively provides a pointer to the 140 * actual data, for a compressed entry this provides the input buffer 141 * for inflate(). 142 */ 143 FileMap* createEntryFileMap(ZipEntryRO entry) const; 144 145 /* 146 * Uncompress the data into a buffer. Depending on the compression 147 * format, this is either an "inflate" operation or a memcpy. 148 * 149 * Use "uncompLen" from getEntryInfo() to determine the required 150 * buffer size. 151 * 152 * Returns "true" on success. 153 */ 154 bool uncompressEntry(ZipEntryRO entry, void* buffer, size_t size) const; 155 156 /* 157 * Uncompress the data to an open file descriptor. 158 */ 159 bool uncompressEntry(ZipEntryRO entry, int fd) const; 160 161 ~ZipFileRO(); 162 163 private: 164 /* these are private and not defined */ 165 ZipFileRO(const ZipFileRO& src); 166 ZipFileRO& operator=(const ZipFileRO& src); 167 ZipFileRO(ZipArchiveHandle handle,char * fileName)168 ZipFileRO(ZipArchiveHandle handle, char* fileName) : mHandle(handle), 169 mFileName(fileName) 170 { 171 } 172 173 const ZipArchiveHandle mHandle; 174 char* mFileName; 175 }; 176 177 }; // namespace android 178 179 #endif /*__LIBS_ZIPFILERO_H*/ 180