chrome/browser/chromeos/file_system_provider/fileapi/file_stream_writer.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_
   6 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/files/file.h"
  10 #include "base/files/file_path.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "storage/browser/fileapi/file_stream_writer.h"
  14 #include "storage/browser/fileapi/file_system_url.h"
  15
  16 namespace chromeos {
  17 namespace file_system_provider {
  18
  19 class ProvidedFileSystemInterface;
  20
  21 // Implements a streamed file writer. It is lazily initialized by the first call
  22 // to Write().
  23 class FileStreamWriter : public storage::FileStreamWriter {
  24  public:
  25   FileStreamWriter(const storage::FileSystemURL& url, int64 initial_offset);
  26
  27   ~FileStreamWriter() override;
  28
  29   // storage::FileStreamWriter overrides.
  30   int Write(net::IOBuffer* buf,
  31             int buf_len,
  32             const net::CompletionCallback& callback) override;
  33   int Cancel(const net::CompletionCallback& callback) override;
  34   int Flush(const net::CompletionCallback& callback) override;
  35
  36  private:
  37   // Helper class for executing operations on the provided file system. All
  38   // of its methods must be called on UI thread. Callbacks are called on IO
  39   // thread.
  40   class OperationRunner;
  41
  42   // State of the file stream writer.
  43   enum State {
  44     NOT_INITIALIZED,
  45     INITIALIZING,
  46     INITIALIZED,
  47     EXECUTING,
  48     FAILED,
  49     CANCELLING
  50   };
  51
  52   // Called when OperationRunner::WriteOnUIThread is completed.
  53   void OnWriteFileCompleted(int buffer_length,
  54                             const net::CompletionCallback& callback,
  55                             base::File::Error result);
  56
  57   // Called when Write() operation is completed with either a success or an
  58   // error.
  59   void OnWriteCompleted(net::CompletionCallback callback, int result);
  60
  61   // Initializes the writer by opening the file. When completed with success,
  62   // runs the |pending_closure|. Otherwise, calls the |error_callback|.
  63   void Initialize(const base::Closure& pending_closure,
  64                   const net::CompletionCallback& error_callback);
  65
  66   // Called when opening a file is completed with either a success or an error.
  67   void OnOpenFileCompleted(
  68       const base::Closure& pending_closure,
  69       const net::CompletionCallback& error_callback,
  70       base::File::Error result);
  71
  72   // Same as Write(), but called after initializing is completed.
  73   void WriteAfterInitialized(scoped_refptr<net::IOBuffer> buffer,
  74                              int buffer_length,
  75                              const net::CompletionCallback& callback);
  76
  77   storage::FileSystemURL url_;
  78   int64 current_offset_;
  79   scoped_refptr<OperationRunner> runner_;
  80   State state_;
  81
  82   base::WeakPtrFactory<FileStreamWriter> weak_ptr_factory_;
  83   DISALLOW_COPY_AND_ASSIGN(FileStreamWriter);
  84 };
  85
  86 }  // namespace file_system_provider
  87 }  // namespace chromeos
  88
  89 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_WRITER_H_