storage/browser/blob/upload_blob_element_reader.h

// Copyright 2015 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 STORAGE_BROWSER_BLOB_UPLOAD_BLOB_ELEMENT_READER_H_
#define STORAGE_BROWSER_BLOB_UPLOAD_BLOB_ELEMENT_READER_H_

#include <stdint.h>

#include <memory>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "net/base/completion_callback.h"
#include "net/base/upload_element_reader.h"
#include "storage/browser/storage_browser_export.h"

namespace base {
class SingleThreadTaskRunner;
}

namespace net {
class IOBuffer;
}

namespace storage {
class BlobDataHandle;
class BlobReader;
class FileSystemContext;

// This class is a wrapper around the BlobReader to make it conform
// to the net::UploadElementReader interface, and it also holds around the
// handle to the blob so it stays in memory while we read it.
class STORAGE_EXPORT UploadBlobElementReader
    : NON_EXPORTED_BASE(public net::UploadElementReader) {
 public:
  UploadBlobElementReader(std::unique_ptr<BlobDataHandle> handle,
                          FileSystemContext* file_system_context,
                          base::SingleThreadTaskRunner* file_task_runner);
  ~UploadBlobElementReader() override;

  int Init(const net::CompletionCallback& callback) override;

  uint64_t GetContentLength() const override;

  uint64_t BytesRemaining() const override;

  bool IsInMemory() const override;

  int Read(net::IOBuffer* buf,
           int buf_length,
           const net::CompletionCallback& callback) override;

  const std::string& uuid() const;

 private:
  std::unique_ptr<BlobDataHandle> handle_;
  scoped_refptr<FileSystemContext> file_system_context_;
  scoped_refptr<base::SingleThreadTaskRunner> file_runner_;
  std::unique_ptr<BlobReader> reader_;

  DISALLOW_COPY_AND_ASSIGN(UploadBlobElementReader);
};

}  // namespace storage
#endif  // STORAGE_BROWSER_BLOB_UPLOAD_BLOB_ELEMENT_READER_H_