1 /* 2 * Copyright (C) 2015 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 #ifndef LIBZIPARCHIVE_ZIPWRITER_H_ 18 #define LIBZIPARCHIVE_ZIPWRITER_H_ 19 20 #include <cstdio> 21 #include <ctime> 22 #include <zlib.h> 23 24 #include <memory> 25 #include <string> 26 #include <vector> 27 28 #include "android-base/macros.h" 29 #include "utils/Compat.h" 30 31 /** 32 * Writes a Zip file via a stateful interface. 33 * 34 * Example: 35 * 36 * FILE* file = fopen("path/to/zip.zip", "wb"); 37 * 38 * ZipWriter writer(file); 39 * 40 * writer.StartEntry("test.txt", ZipWriter::kCompress | ZipWriter::kAlign); 41 * writer.WriteBytes(buffer, bufferLen); 42 * writer.WriteBytes(buffer2, bufferLen2); 43 * writer.FinishEntry(); 44 * 45 * writer.StartEntry("empty.txt", 0); 46 * writer.FinishEntry(); 47 * 48 * writer.Finish(); 49 * 50 * fclose(file); 51 */ 52 class ZipWriter { 53 public: 54 enum { 55 /** 56 * Flag to compress the zip entry using deflate. 57 */ 58 kCompress = 0x01, 59 60 /** 61 * Flag to align the zip entry data on a 32bit boundary. Useful for 62 * mmapping the data at runtime. 63 */ 64 kAlign32 = 0x02, 65 }; 66 67 /** 68 * A struct representing a zip file entry. 69 */ 70 struct FileEntry { 71 std::string path; 72 uint16_t compression_method; 73 uint32_t crc32; 74 uint32_t compressed_size; 75 uint32_t uncompressed_size; 76 uint16_t last_mod_time; 77 uint16_t last_mod_date; 78 uint32_t padding_length; 79 off64_t local_file_header_offset; 80 }; 81 82 static const char* ErrorCodeString(int32_t error_code); 83 84 /** 85 * Create a ZipWriter that will write into a FILE stream. The file should be opened with 86 * open mode of "wb" or "w+b". ZipWriter does not take ownership of the file stream. The 87 * caller is responsible for closing the file. 88 */ 89 explicit ZipWriter(FILE* f); 90 91 // Move constructor. 92 ZipWriter(ZipWriter&& zipWriter); 93 94 // Move assignment. 95 ZipWriter& operator=(ZipWriter&& zipWriter); 96 97 /** 98 * Starts a new zip entry with the given path and flags. 99 * Flags can be a bitwise OR of ZipWriter::kCompress and ZipWriter::kAlign. 100 * Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry. 101 * Returns 0 on success, and an error value < 0 on failure. 102 */ 103 int32_t StartEntry(const char* path, size_t flags); 104 105 /** 106 * Starts a new zip entry with the given path and flags, where the 107 * entry will be aligned to the given alignment. 108 * Flags can only be ZipWriter::kCompress. Using the flag ZipWriter::kAlign32 109 * will result in an error. 110 * Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry. 111 * Returns 0 on success, and an error value < 0 on failure. 112 */ 113 int32_t StartAlignedEntry(const char* path, size_t flags, uint32_t alignment); 114 115 /** 116 * Same as StartEntry(const char*, size_t), but sets a last modified time for the entry. 117 */ 118 int32_t StartEntryWithTime(const char* path, size_t flags, time_t time); 119 120 /** 121 * Same as StartAlignedEntry(const char*, size_t), but sets a last modified time for the entry. 122 */ 123 int32_t StartAlignedEntryWithTime(const char* path, size_t flags, time_t time, 124 uint32_t alignment); 125 126 /** 127 * Writes bytes to the zip file for the previously started zip entry. 128 * Returns 0 on success, and an error value < 0 on failure. 129 */ 130 int32_t WriteBytes(const void* data, size_t len); 131 132 /** 133 * Finish a zip entry started with StartEntry(const char*, size_t) or 134 * StartEntryWithTime(const char*, size_t, time_t). This must be called before 135 * any new zip entries are started, or before Finish() is called. 136 * Returns 0 on success, and an error value < 0 on failure. 137 */ 138 int32_t FinishEntry(); 139 140 /** 141 * Discards the last-written entry. Can only be called after an entry has been written using 142 * FinishEntry(). 143 * Returns 0 on success, and an error value < 0 on failure. 144 */ 145 int32_t DiscardLastEntry(); 146 147 /** 148 * Sets `out_entry` to the last entry written after a call to FinishEntry(). 149 * Returns 0 on success, and an error value < 0 if no entries have been written. 150 */ 151 int32_t GetLastEntry(FileEntry* out_entry); 152 153 /** 154 * Writes the Central Directory Headers and flushes the zip file stream. 155 * Returns 0 on success, and an error value < 0 on failure. 156 */ 157 int32_t Finish(); 158 159 private: 160 DISALLOW_COPY_AND_ASSIGN(ZipWriter); 161 162 int32_t HandleError(int32_t error_code); 163 int32_t PrepareDeflate(); 164 int32_t StoreBytes(FileEntry* file, const void* data, size_t len); 165 int32_t CompressBytes(FileEntry* file, const void* data, size_t len); 166 int32_t FlushCompressedBytes(FileEntry* file); 167 168 enum class State { 169 kWritingZip, 170 kWritingEntry, 171 kDone, 172 kError, 173 }; 174 175 FILE* file_; 176 bool seekable_; 177 off64_t current_offset_; 178 State state_; 179 std::vector<FileEntry> files_; 180 FileEntry current_file_entry_; 181 182 std::unique_ptr<z_stream, void(*)(z_stream*)> z_stream_; 183 std::vector<uint8_t> buffer_; 184 }; 185 186 #endif /* LIBZIPARCHIVE_ZIPWRITER_H_ */ 187
