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//
// Copyright (C) 2020 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 <optional>
#include <vector>
#include <android-base/file.h>
#include <libsnapshot/cow_reader.h>
#include <payload_consumer/file_descriptor.h>
namespace android {
namespace snapshot {
class ReadOnlyFileDescriptor : public chromeos_update_engine::FileDescriptor {
public:
bool Open(const char* path, int flags, mode_t mode) override;
bool Open(const char* path, int flags) override;
ssize_t Write(const void* buf, size_t count) override;
bool BlkIoctl(int request, uint64_t start, uint64_t length, int* result) override;
};
class ReadFdFileDescriptor : public ReadOnlyFileDescriptor {
public:
explicit ReadFdFileDescriptor(android::base::unique_fd&& fd);
ssize_t Read(void* buf, size_t count) override;
off64_t Seek(off64_t offset, int whence) override;
uint64_t BlockDevSize() override;
bool Close() override;
bool IsSettingErrno() override;
bool IsOpen() override;
bool Flush() override;
private:
android::base::unique_fd fd_;
};
class CompressedSnapshotReader : public ReadOnlyFileDescriptor {
public:
bool SetCow(std::unique_ptr<CowReader>&& cow);
void SetSourceDevice(const std::string& source_device);
void SetBlockDeviceSize(uint64_t block_device_size);
ssize_t Read(void* buf, size_t count) override;
off64_t Seek(off64_t offset, int whence) override;
uint64_t BlockDevSize() override;
bool Close() override;
bool IsSettingErrno() override;
bool IsOpen() override;
bool Flush() override;
private:
ssize_t ReadBlock(uint64_t chunk, IByteSink* sink, size_t start_offset,
const std::optional<uint64_t>& max_bytes = {});
android::base::borrowed_fd GetSourceFd();
std::unique_ptr<CowReader> cow_;
std::unique_ptr<ICowOpIter> op_iter_;
uint32_t block_size_ = 0;
std::optional<std::string> source_device_;
android::base::unique_fd source_fd_;
uint64_t block_device_size_ = 0;
off64_t offset_ = 0;
std::vector<const CowOperation*> ops_;
};
} // namespace snapshot
} // namespace android
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