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// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_ZUCCHINI_MAPPED_FILE_H_
#define COMPONENTS_ZUCCHINI_MAPPED_FILE_H_
#include <stddef.h>
#include <stdint.h>
#include <string>
#include "base/files/file.h"
#include "base/files/file_path.h"
#include "base/files/memory_mapped_file.h"
#include "components/zucchini/buffer_view.h"
namespace zucchini {
// A file reader wrapper.
class MappedFileReader {
public:
// Maps |file| to memory for reading. Also validates |file|. Errors are
// available via HasError() and error().
explicit MappedFileReader(base::File file);
MappedFileReader(const MappedFileReader&) = delete;
const MappedFileReader& operator=(const MappedFileReader&) = delete;
const uint8_t* data() const { return buffer_.data(); }
size_t length() const { return buffer_.length(); }
zucchini::ConstBufferView region() const { return {data(), length()}; }
bool HasError() { return !error_.empty() || !buffer_.IsValid(); }
const std::string& error() { return error_; }
private:
std::string error_;
base::MemoryMappedFile buffer_;
};
// A file writer wrapper. The target file is deleted on destruction unless
// Keep() is called.
class MappedFileWriter {
public:
// Maps |file| to memory for writing. |file_path| is needed for auto delete on
// UNIX systems, but can be empty if auto delete is not needed. Errors are
// available via HasError() and error().
MappedFileWriter(const base::FilePath& file_path,
base::File file,
size_t length);
MappedFileWriter(const MappedFileWriter&) = delete;
const MappedFileWriter& operator=(const MappedFileWriter&) = delete;
~MappedFileWriter();
uint8_t* data() { return buffer_.data(); }
size_t length() const { return buffer_.length(); }
zucchini::MutableBufferView region() { return {data(), length()}; }
bool HasError() { return !error_.empty() || !buffer_.IsValid(); }
const std::string& error() { return error_; }
// Indicates that the file should not be deleted on destruction. Returns true
// iff the operation succeeds.
bool Keep();
private:
enum OnCloseDeleteBehavior {
kKeep,
kAutoDeleteOnClose,
kManualDeleteOnClose
};
std::string error_;
base::FilePath file_path_;
base::File file_handle_;
base::MemoryMappedFile buffer_;
OnCloseDeleteBehavior delete_behavior_;
};
} // namespace zucchini
#endif // COMPONENTS_ZUCCHINI_MAPPED_FILE_H_
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