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 #pragma once 18 19 #include <cstdio> 20 #include <ctime> 21 22 #include <gtest/gtest_prod.h> 23 #include <memory> 24 #include <string> 25 #include <string_view> 26 #include <vector> 27 28 #include "android-base/macros.h" 29 #include "android-base/off64_t.h" 30 31 struct z_stream_s; 32 typedef struct z_stream_s z_stream; 33 34 /** 35 * Writes a Zip file via a stateful interface. 36 * 37 * Example: 38 * 39 * FILE* file = fopen("path/to/zip.zip", "wb"); 40 * 41 * ZipWriter writer(file); 42 * 43 * writer.StartEntry("test.txt", ZipWriter::kCompress | ZipWriter::kAlign); 44 * writer.WriteBytes(buffer, bufferLen); 45 * writer.WriteBytes(buffer2, bufferLen2); 46 * writer.FinishEntry(); 47 * 48 * writer.StartEntry("empty.txt", 0); 49 * writer.FinishEntry(); 50 * 51 * writer.Finish(); 52 * 53 * fclose(file); 54 */ 55 class ZipWriter { 56 public: 57 enum { 58 /** 59 * Flag to compress the zip entry using deflate. 60 */ 61 kCompress = 0x01, 62 63 /** 64 * Flag to align the zip entry data on a 32bit boundary. Useful for 65 * mmapping the data at runtime. 66 */ 67 kAlign32 = 0x02, 68 }; 69 70 /** 71 * A struct representing a zip file entry. 72 */ 73 struct FileEntry { 74 std::string path; 75 uint16_t compression_method; 76 uint32_t crc32; 77 uint32_t compressed_size; 78 uint32_t uncompressed_size; 79 uint16_t last_mod_time; 80 uint16_t last_mod_date; 81 uint16_t padding_length; 82 off64_t local_file_header_offset; 83 }; 84 85 static const char* ErrorCodeString(int32_t error_code); 86 87 /** 88 * Create a ZipWriter that will write into a FILE stream. The file should be opened with 89 * open mode of "wb" or "w+b". ZipWriter does not take ownership of the file stream. The 90 * caller is responsible for closing the file. 91 */ 92 explicit ZipWriter(FILE* f); 93 94 // Move constructor. 95 ZipWriter(ZipWriter&& zipWriter) noexcept; 96 97 // Move assignment. 98 ZipWriter& operator=(ZipWriter&& zipWriter) noexcept; 99 100 /** 101 * Starts a new zip entry with the given path and flags. 102 * Flags can be a bitwise OR of ZipWriter::kCompress and ZipWriter::kAlign. 103 * Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry. 104 * Returns 0 on success, and an error value < 0 on failure. 105 */ 106 int32_t StartEntry(std::string_view path, size_t flags); 107 108 /** 109 * Starts a new zip entry with the given path and flags, where the 110 * entry will be aligned to the given alignment. 111 * Flags can only be ZipWriter::kCompress. Using the flag ZipWriter::kAlign32 112 * will result in an error. 113 * Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry. 114 * Returns 0 on success, and an error value < 0 on failure. 115 */ 116 int32_t StartAlignedEntry(std::string_view path, size_t flags, uint32_t alignment); 117 118 /** 119 * Same as StartEntry(const char*, size_t), but sets a last modified time for the entry. 120 */ 121 int32_t StartEntryWithTime(std::string_view path, size_t flags, time_t time); 122 123 /** 124 * Same as StartAlignedEntry(const char*, size_t), but sets a last modified time for the entry. 125 */ 126 int32_t StartAlignedEntryWithTime(std::string_view path, size_t flags, time_t time, uint32_t alignment); 127 128 /** 129 * Writes bytes to the zip file for the previously started zip entry. 130 * Returns 0 on success, and an error value < 0 on failure. 131 */ 132 int32_t WriteBytes(const void* data, size_t len); 133 134 /** 135 * Finish a zip entry started with StartEntry(const char*, size_t) or 136 * StartEntryWithTime(const char*, size_t, time_t). This must be called before 137 * any new zip entries are started, or before Finish() is called. 138 * Returns 0 on success, and an error value < 0 on failure. 139 */ 140 int32_t FinishEntry(); 141 142 /** 143 * Discards the last-written entry. Can only be called after an entry has been written using 144 * FinishEntry(). 145 * Returns 0 on success, and an error value < 0 on failure. 146 */ 147 int32_t DiscardLastEntry(); 148 149 /** 150 * Sets `out_entry` to the last entry written after a call to FinishEntry(). 151 * Returns 0 on success, and an error value < 0 if no entries have been written. 152 */ 153 int32_t GetLastEntry(FileEntry* out_entry); 154 155 /** 156 * Writes the Central Directory Headers and flushes the zip file stream. 157 * Returns 0 on success, and an error value < 0 on failure. 158 */ 159 int32_t Finish(); 160 161 private: 162 DISALLOW_COPY_AND_ASSIGN(ZipWriter); 163 164 int32_t HandleError(int32_t error_code); 165 int32_t PrepareDeflate(); 166 int32_t StoreBytes(FileEntry* file, const void* data, uint32_t len); 167 int32_t CompressBytes(FileEntry* file, const void* data, uint32_t len); 168 int32_t FlushCompressedBytes(FileEntry* file); 169 bool ShouldUseDataDescriptor() const; 170 171 enum class State { 172 kWritingZip, 173 kWritingEntry, 174 kDone, 175 kError, 176 }; 177 178 FILE* file_; 179 bool seekable_; 180 off64_t current_offset_; 181 State state_; 182 std::vector<FileEntry> files_; 183 FileEntry current_file_entry_; 184 185 std::unique_ptr<z_stream, void (*)(z_stream*)> z_stream_; 186 std::vector<uint8_t> buffer_; 187 188 FRIEND_TEST(zipwriter, WriteToUnseekableFile); 189 }; 190