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// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MOJO_PUBLIC_CPP_SYSTEM_FILE_DATA_SOURCE_H_
#define MOJO_PUBLIC_CPP_SYSTEM_FILE_DATA_SOURCE_H_
#include "base/containers/span.h"
#include "base/files/file.h"
#include "mojo/public/cpp/system/data_pipe_producer.h"
#include "mojo/public/cpp/system/system_export.h"
namespace mojo {
// A class to wrap base::File as DataPipeProducer::DataSource class. Reads at
// most |max_bytes| bytes from the file.
class MOJO_CPP_SYSTEM_EXPORT FileDataSource final
: public DataPipeProducer::DataSource {
public:
static MojoResult ConvertFileErrorToMojoResult(base::File::Error error);
FileDataSource(base::File file);
FileDataSource(const FileDataSource&) = delete;
FileDataSource& operator=(const FileDataSource&) = delete;
~FileDataSource() override;
// |end| should be greater than or equal to |start|. Otherwise subsequent
// Read() fails with MOJO_RESULT_INVALID_ARGUMENT. [start, end) will be read.
void SetRange(uint64_t start, uint64_t end);
// DataPipeProducer::DataSource:
uint64_t GetLength() const override;
ReadResult Read(uint64_t offset, base::span<char> buffer) override;
private:
base::File file_;
MojoResult error_;
uint64_t start_offset_;
uint64_t end_offset_;
};
} // namespace mojo
#endif // MOJO_PUBLIC_CPP_SYSTEM_FILE_DATA_SOURCE_H_
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