device/serial/data_source_sender.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 DEVICE_SERIAL_DATA_SOURCE_SENDER_H_
   6 #define DEVICE_SERIAL_DATA_SOURCE_SENDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "device/serial/buffer.h"
  11 #include "device/serial/data_stream.mojom.h"
  12 #include "mojo/public/cpp/system/data_pipe.h"
  13
  14 namespace device {
  15
  16 class AsyncWaiter;
  17
  18 // A DataSourceSender is an interface between a source of data and a data pipe.
  19 class DataSourceSender : public base::RefCounted<DataSourceSender>,
  20                          public mojo::InterfaceImpl<serial::DataSource> {
  21  public:
  22   typedef base::Callback<void(scoped_ptr<WritableBuffer>)> ReadyCallback;
  23   typedef base::Callback<void()> ErrorCallback;
  24
  25   // Constructs a DataSourceSender. Whenever the pipe is ready for writing, the
  26   // |ready_callback| will be called with the WritableBuffer to be filled.
  27   // |ready_callback| will not be called again until the previous WritableBuffer
  28   // is destroyed. If a connection error occurs, |error_callback| will be
  29   // called and the DataSourceSender will act as if ShutDown() had been called.
  30   DataSourceSender(const ReadyCallback& ready_callback,
  31                    const ErrorCallback& error_callback);
  32
  33   // Shuts down this DataSourceSender. After shut down, |ready_callback| and
  34   // |error_callback| will never be called.
  35   void ShutDown();
  36
  37  private:
  38   friend class base::RefCounted<DataSourceSender>;
  39   class PendingSend;
  40
  41   virtual ~DataSourceSender();
  42
  43   // mojo::InterfaceImpl<serial::DataSourceSender> overrides.
  44   virtual void Init(mojo::ScopedDataPipeProducerHandle handle) OVERRIDE;
  45   virtual void Resume() OVERRIDE;
  46   // Invoked in the event of a connection error. Calls DispatchFatalError().
  47   virtual void OnConnectionError() OVERRIDE;
  48
  49   // Starts waiting for |handle_| to be ready for writes.
  50   void StartWaiting();
  51
  52   // Invoked when |handle_| is ready for writes.
  53   void OnDoneWaiting(MojoResult result);
  54
  55   // Reports a successful write of |bytes_written|.
  56   void Done(uint32_t bytes_written);
  57
  58   // Reports a partially successful or unsuccessful write of |bytes_written|
  59   // with an error of |error|.
  60   void DoneWithError(uint32_t bytes_written, int32_t error);
  61
  62   // Finishes the two-phase data pipe write.
  63   void DoneInternal(uint32_t bytes_written);
  64
  65   // Reports a fatal error to the client and shuts down.
  66   void DispatchFatalError();
  67
  68   // The data connection to the data receiver.
  69   mojo::ScopedDataPipeProducerHandle handle_;
  70
  71   // The callback to call when |handle_| is ready for more data.
  72   ReadyCallback ready_callback_;
  73
  74   // The callback to call if a fatal error occurs.
  75   ErrorCallback error_callback_;
  76
  77   // The current pending send operation if there is one.
  78   scoped_ptr<PendingSend> pending_send_;
  79
  80   // A waiter used to wait until |handle_| is writable if we are waiting.
  81   scoped_ptr<AsyncWaiter> waiter_;
  82
  83   // The number of bytes sent to the data receiver.
  84   uint32_t bytes_sent_;
  85
  86   // Whether we have encountered a fatal error and shut down.
  87   bool shut_down_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(DataSourceSender);
  90 };
  91
  92 }  // namespace device
  93
  94 #endif  // DEVICE_SERIAL_DATA_SOURCE_SENDER_H_