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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_ASH_FILE_SYSTEM_PROVIDER_FILEAPI_BUFFERING_FILE_STREAM_WRITER_H_
#define CHROME_BROWSER_ASH_FILE_SYSTEM_PROVIDER_FILEAPI_BUFFERING_FILE_STREAM_WRITER_H_
#include <memory>
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "net/base/completion_once_callback.h"
#include "storage/browser/file_system/file_stream_writer.h"
namespace net {
class IOBuffer;
} // namespace net
namespace ash::file_system_provider {
// Wraps the file stream writer implementation with an intermediate buffer.
// Writes data from the inner file stream writer in chunks of size at least
// |intermediate_buffer_length| bytes (or less for the last chunk, or when
// Flush() is explicitely called).
//
// The underlying inner file stream writer *must not* return any values
// synchronously. Instead, results must be returned by a callback, including
// errors. Moreover, partial writes are *not* supported.
class BufferingFileStreamWriter : public storage::FileStreamWriter {
public:
BufferingFileStreamWriter(
std::unique_ptr<storage::FileStreamWriter> file_stream_writer,
int intermediate_buffer_length);
BufferingFileStreamWriter(const BufferingFileStreamWriter&) = delete;
BufferingFileStreamWriter& operator=(const BufferingFileStreamWriter&) =
delete;
~BufferingFileStreamWriter() override;
// storage::FileStreamWriter overrides.
int Write(net::IOBuffer* buf,
int buf_len,
net::CompletionOnceCallback callback) override;
int Cancel(net::CompletionOnceCallback callback) override;
int Flush(storage::FlushMode flush_mode,
net::CompletionOnceCallback callback) override;
private:
// Copies |buffer_length| bytes of data from the |buffer| starting at
// |buffer_offset| position to the current position of the intermediate
// buffer.
void CopyToIntermediateBuffer(scoped_refptr<net::IOBuffer> buffer,
int buffer_offset,
int buffer_length);
// Flushes all of the bytes in the intermediate buffer to the inner file
// stream writer.
void FlushIntermediateBuffer(net::CompletionOnceCallback callback);
// Called when flushing the intermediate buffer is completed with either
// a success or an error.
void OnFlushIntermediateBufferCompleted(int length,
net::CompletionOnceCallback callback,
int result);
// Called when flushing the intermediate buffer for direct write is completed
// with either a success or an error.
void OnFlushIntermediateBufferForDirectWriteCompleted(
scoped_refptr<net::IOBuffer> buffer,
int length,
net::CompletionOnceCallback callback,
int result);
// Called when flushing the intermediate buffer for a buffered write is
// completed with either a success or an error.
void OnFlushIntermediateBufferForBufferedWriteCompleted(
scoped_refptr<net::IOBuffer> buffer,
int buffered_bytes,
int bytes_left,
net::CompletionOnceCallback callback,
int result);
// Called when flushing the intermediate buffer for a flush call is completed
// with either a success or an error.
void OnFlushIntermediateBufferForFlushCompleted(
net::CompletionOnceCallback callback,
storage::FlushMode flush_mode,
int result);
std::unique_ptr<storage::FileStreamWriter> file_stream_writer_;
int intermediate_buffer_length_;
scoped_refptr<net::IOBuffer> intermediate_buffer_;
int buffered_bytes_;
base::WeakPtrFactory<BufferingFileStreamWriter> weak_ptr_factory_{this};
};
} // namespace ash::file_system_provider
#endif // CHROME_BROWSER_ASH_FILE_SYSTEM_PROVIDER_FILEAPI_BUFFERING_FILE_STREAM_WRITER_H_
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