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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <cstdio>
#include <ctime>
#include <gtest/gtest_prod.h>
#include <memory>
#include <string>
#include <string_view>
#include <vector>
#include "android-base/macros.h"
#include "android-base/off64_t.h"
struct z_stream_s;
typedef struct z_stream_s z_stream;
/**
* Writes a Zip file via a stateful interface.
*
* Example:
*
* FILE* file = fopen("path/to/zip.zip", "wb");
*
* ZipWriter writer(file);
*
* writer.StartEntry("test.txt", ZipWriter::kCompress | ZipWriter::kAlign);
* writer.WriteBytes(buffer, bufferLen);
* writer.WriteBytes(buffer2, bufferLen2);
* writer.FinishEntry();
*
* writer.StartEntry("empty.txt", 0);
* writer.FinishEntry();
*
* writer.Finish();
*
* fclose(file);
*/
class ZipWriter {
public:
enum {
/**
* Flag to compress the zip entry using deflate.
*/
kCompress = 0x01,
/**
* Flag to align the zip entry data on a 32bit boundary. Useful for
* mmapping the data at runtime.
*/
kAlign32 = 0x02,
};
/**
* A struct representing a zip file entry.
*/
struct FileEntry {
std::string path;
uint16_t compression_method;
uint32_t crc32;
uint32_t compressed_size;
uint32_t uncompressed_size;
uint16_t last_mod_time;
uint16_t last_mod_date;
uint16_t padding_length;
off64_t local_file_header_offset;
};
static const char* ErrorCodeString(int32_t error_code);
/**
* Create a ZipWriter that will write into a FILE stream. The file should be opened with
* open mode of "wb" or "w+b". ZipWriter does not take ownership of the file stream. The
* caller is responsible for closing the file.
*/
explicit ZipWriter(FILE* f);
// Move constructor.
ZipWriter(ZipWriter&& zipWriter) noexcept;
// Move assignment.
ZipWriter& operator=(ZipWriter&& zipWriter) noexcept;
/**
* Starts a new zip entry with the given path and flags.
* Flags can be a bitwise OR of ZipWriter::kCompress and ZipWriter::kAlign.
* Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry.
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t StartEntry(std::string_view path, size_t flags);
/**
* Starts a new zip entry with the given path and flags, where the
* entry will be aligned to the given alignment.
* Flags can only be ZipWriter::kCompress. Using the flag ZipWriter::kAlign32
* will result in an error.
* Subsequent calls to WriteBytes(const void*, size_t) will add data to this entry.
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t StartAlignedEntry(std::string_view path, size_t flags, uint32_t alignment);
/**
* Same as StartEntry(const char*, size_t), but sets a last modified time for the entry.
*/
int32_t StartEntryWithTime(std::string_view path, size_t flags, time_t time);
/**
* Same as StartAlignedEntry(const char*, size_t), but sets a last modified time for the entry.
*/
int32_t StartAlignedEntryWithTime(std::string_view path, size_t flags, time_t time, uint32_t alignment);
/**
* Writes bytes to the zip file for the previously started zip entry.
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t WriteBytes(const void* data, size_t len);
/**
* Finish a zip entry started with StartEntry(const char*, size_t) or
* StartEntryWithTime(const char*, size_t, time_t). This must be called before
* any new zip entries are started, or before Finish() is called.
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t FinishEntry();
/**
* Discards the last-written entry. Can only be called after an entry has been written using
* FinishEntry().
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t DiscardLastEntry();
/**
* Sets `out_entry` to the last entry written after a call to FinishEntry().
* Returns 0 on success, and an error value < 0 if no entries have been written.
*/
int32_t GetLastEntry(FileEntry* out_entry);
/**
* Writes the Central Directory Headers and flushes the zip file stream.
* Returns 0 on success, and an error value < 0 on failure.
*/
int32_t Finish();
private:
DISALLOW_COPY_AND_ASSIGN(ZipWriter);
int32_t HandleError(int32_t error_code);
int32_t PrepareDeflate();
int32_t StoreBytes(FileEntry* file, const void* data, uint32_t len);
int32_t CompressBytes(FileEntry* file, const void* data, uint32_t len);
int32_t FlushCompressedBytes(FileEntry* file);
bool ShouldUseDataDescriptor() const;
enum class State {
kWritingZip,
kWritingEntry,
kDone,
kError,
};
FILE* file_;
bool seekable_;
off64_t current_offset_;
State state_;
std::vector<FileEntry> files_;
FileEntry current_file_entry_;
std::unique_ptr<z_stream, void (*)(z_stream*)> z_stream_;
std::vector<uint8_t> buffer_;
FRIEND_TEST(zipwriter, WriteToUnseekableFile);
};