Narayan Kamath | 7462f02 | 2013-11-21 13:05:04 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2013 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 | #ifndef LIBZIPARCHIVE_ZIPARCHIVE_H_ |
| 21 | #define LIBZIPARCHIVE_ZIPARCHIVE_H_ |
| 22 | |
| 23 | #include <stdint.h> |
| 24 | #include <sys/types.h> |
Narayan Kamath | 574c3b3 | 2013-12-06 18:27:53 +0000 | [diff] [blame] | 25 | #include <utils/Compat.h> |
Narayan Kamath | 7462f02 | 2013-11-21 13:05:04 +0000 | [diff] [blame] | 26 | |
| 27 | __BEGIN_DECLS |
| 28 | |
| 29 | /* Zip compression methods we support */ |
| 30 | enum { |
| 31 | kCompressStored = 0, // no compression |
| 32 | kCompressDeflated = 8, // standard deflate |
| 33 | }; |
| 34 | |
| 35 | struct ZipEntryName { |
| 36 | const char* name; |
| 37 | uint16_t name_length; |
| 38 | }; |
| 39 | |
| 40 | /* |
| 41 | * Represents information about a zip entry in a zip file. |
| 42 | */ |
| 43 | struct ZipEntry { |
| 44 | // Compression method: One of kCompressStored or |
| 45 | // kCompressDeflated. |
| 46 | uint16_t method; |
| 47 | |
| 48 | // Modification time. The zipfile format specifies |
| 49 | // that the first two little endian bytes contain the time |
| 50 | // and the last two little endian bytes contain the date. |
| 51 | uint32_t mod_time; |
| 52 | |
| 53 | // 1 if this entry contains a data descriptor segment, 0 |
| 54 | // otherwise. |
| 55 | uint8_t has_data_descriptor; |
| 56 | |
| 57 | // Crc32 value of this ZipEntry. This information might |
| 58 | // either be stored in the local file header or in a special |
| 59 | // Data descriptor footer at the end of the file entry. |
| 60 | uint32_t crc32; |
| 61 | |
| 62 | // Compressed length of this ZipEntry. Might be present |
| 63 | // either in the local file header or in the data descriptor |
| 64 | // footer. |
| 65 | uint32_t compressed_length; |
| 66 | |
| 67 | // Uncompressed length of this ZipEntry. Might be present |
| 68 | // either in the local file header or in the data descriptor |
| 69 | // footer. |
| 70 | uint32_t uncompressed_length; |
| 71 | |
| 72 | // The offset to the start of data for this ZipEntry. |
| 73 | off64_t offset; |
| 74 | }; |
| 75 | |
| 76 | typedef void* ZipArchiveHandle; |
| 77 | |
| 78 | /* |
| 79 | * Open a Zip archive, and sets handle to the value of the opaque |
| 80 | * handle for the file. This handle must be released by calling |
| 81 | * CloseArchive with this handle. |
| 82 | * |
| 83 | * Returns 0 on success, and negative values on failure. |
| 84 | */ |
| 85 | int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle); |
| 86 | |
| 87 | /* |
| 88 | * Like OpenArchive, but takes a file descriptor open for reading |
| 89 | * at the start of the file. The descriptor must be mappable (this does |
| 90 | * not allow access to a stream). |
| 91 | * |
| 92 | * Sets handle to the value of the opaque handle for this file descriptor. |
| 93 | * This handle must be released by calling CloseArchive with this handle. |
| 94 | * |
| 95 | * This function maps and scans the central directory and builds a table |
| 96 | * of entries for future lookups. |
| 97 | * |
| 98 | * "debugFileName" will appear in error messages, but is not otherwise used. |
| 99 | * |
| 100 | * Returns 0 on success, and negative values on failure. |
| 101 | */ |
| 102 | int32_t OpenArchiveFd(const int fd, const char* debugFileName, |
| 103 | ZipArchiveHandle *handle); |
| 104 | |
| 105 | /* |
| 106 | * Close archive, releasing resources associated with it. This will |
| 107 | * unmap the central directory of the zipfile and free all internal |
| 108 | * data structures associated with the file. It is an error to use |
| 109 | * this handle for any further operations without an intervening |
| 110 | * call to one of the OpenArchive variants. |
| 111 | */ |
| 112 | void CloseArchive(ZipArchiveHandle handle); |
| 113 | |
| 114 | /* |
| 115 | * Find an entry in the Zip archive, by name. |entryName| must be a null |
| 116 | * terminated string, and |data| must point to a writeable memory location. |
| 117 | * |
| 118 | * Returns 0 if an entry is found, and populates |data| with information |
| 119 | * about this entry. Returns negative values otherwise. |
| 120 | * |
| 121 | * It's important to note that |data->crc32|, |data->compLen| and |
| 122 | * |data->uncompLen| might be set to values from the central directory |
| 123 | * if this file entry contains a data descriptor footer. To verify crc32s |
| 124 | * and length, a call to VerifyCrcAndLengths must be made after entry data |
| 125 | * has been processed. |
| 126 | */ |
| 127 | int32_t FindEntry(const ZipArchiveHandle handle, const char* entryName, |
| 128 | ZipEntry* data); |
| 129 | |
| 130 | /* |
| 131 | * Start iterating over all entries of a zip file. The order of iteration |
| 132 | * is not guaranteed to be the same as the order of elements |
| 133 | * in the central directory but is stable for a given zip file. |cookie| |
| 134 | * must point to a writeable memory location, and will be set to the value |
| 135 | * of an opaque cookie which can be used to make one or more calls to |
| 136 | * Next. |
| 137 | * |
| 138 | * This method also accepts an optional prefix to restrict iteration to |
| 139 | * entry names that start with |prefix|. |
| 140 | * |
| 141 | * Returns 0 on success and negative values on failure. |
| 142 | */ |
| 143 | int32_t StartIteration(ZipArchiveHandle handle, void** cookie_ptr, |
| 144 | const char* prefix); |
| 145 | |
| 146 | /* |
| 147 | * Advance to the next element in the zipfile in iteration order. |
| 148 | * |
| 149 | * Returns 0 on success, -1 if there are no more elements in this |
| 150 | * archive and lower negative values on failure. |
| 151 | */ |
| 152 | int32_t Next(void* cookie, ZipEntry* data, ZipEntryName *name); |
| 153 | |
| 154 | /* |
Narayan Kamath | 00a258c | 2013-12-13 16:06:19 +0000 | [diff] [blame] | 155 | * Uncompress and write an entry to an open file identified by |fd|. |
| 156 | * |entry->uncompressed_length| bytes will be written to the file at |
| 157 | * its current offset, and the file will be truncated at the end of |
| 158 | * the uncompressed data. |
Narayan Kamath | 7462f02 | 2013-11-21 13:05:04 +0000 | [diff] [blame] | 159 | * |
| 160 | * Returns 0 on success and negative values on failure. |
| 161 | */ |
| 162 | int32_t ExtractEntryToFile(ZipArchiveHandle handle, ZipEntry* entry, int fd); |
| 163 | |
| 164 | /** |
| 165 | * Uncompress a given zip entry to the memory region at |begin| and of |
| 166 | * size |size|. This size is expected to be the same as the *declared* |
| 167 | * uncompressed length of the zip entry. It is an error if the *actual* |
| 168 | * number of uncompressed bytes differs from this number. |
| 169 | * |
| 170 | * Returns 0 on success and negative values on failure. |
| 171 | */ |
| 172 | int32_t ExtractToMemory(ZipArchiveHandle handle, ZipEntry* entry, |
| 173 | uint8_t* begin, uint32_t size); |
| 174 | |
| 175 | int GetFileDescriptor(const ZipArchiveHandle handle); |
| 176 | |
| 177 | const char* ErrorCodeString(int32_t error_code); |
| 178 | |
| 179 | __END_DECLS |
| 180 | |
| 181 | #endif // LIBZIPARCHIVE_ZIPARCHIVE_H_ |