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 <vector>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "device/serial/buffer.h"
  14 #include "device/serial/data_stream.mojom.h"
  15 #include "mojo/public/cpp/system/data_pipe.h"
  16
  17 namespace device {
  18
  19 // A DataSourceSender is an interface between a source of data and a
  20 // DataSourceClient.
  21 class DataSourceSender : public base::RefCounted<DataSourceSender>,
  22                          public mojo::InterfaceImpl<serial::DataSource> {
  23  public:
  24   typedef base::Callback<void(scoped_ptr<WritableBuffer>)> ReadyCallback;
  25   typedef base::Callback<void()> ErrorCallback;
  26
  27   // Constructs a DataSourceSender. Whenever the pipe is ready for writing, the
  28   // |ready_callback| will be called with the WritableBuffer to be filled.
  29   // |ready_callback| will not be called again until the previous WritableBuffer
  30   // is destroyed. If a connection error occurs, |error_callback| will be
  31   // called and the DataSourceSender will act as if ShutDown() had been called.
  32   DataSourceSender(const ReadyCallback& ready_callback,
  33                    const ErrorCallback& error_callback);
  34
  35   // Shuts down this DataSourceSender. After shut down, |ready_callback| and
  36   // |error_callback| will never be called.
  37   void ShutDown();
  38
  39  private:
  40   friend class base::RefCounted<DataSourceSender>;
  41   class PendingSend;
  42
  43   ~DataSourceSender() override;
  44
  45   // mojo::InterfaceImpl<serial::DataSourceSender> overrides.
  46   void Init(uint32_t buffer_size) override;
  47   void Resume() override;
  48   void ReportBytesReceived(uint32_t bytes_sent) override;
  49   // Invoked in the event of a connection error. Calls DispatchFatalError().
  50   void OnConnectionError() override;
  51
  52   // Gets more data to send to the DataSourceClient.
  53   void GetMoreData();
  54
  55   // Invoked to pass |data| obtained in response to |ready_callback_|.
  56   void Done(const std::vector<char>& data);
  57
  58   // Invoked to pass |data| and |error| obtained in response to
  59   // |ready_callback_|.
  60   void DoneWithError(const std::vector<char>& data, int32_t error);
  61
  62   // Dispatches |data| to the client.
  63   void DoneInternal(const std::vector<char>& data);
  64
  65   // Reports a fatal error to the client and shuts down.
  66   void DispatchFatalError();
  67
  68   // The callback to call when the client is ready for more data.
  69   ReadyCallback ready_callback_;
  70
  71   // The callback to call if a fatal error occurs.
  72   ErrorCallback error_callback_;
  73
  74   // The current pending send operation if there is one.
  75   scoped_ptr<PendingSend> pending_send_;
  76
  77   // The number of bytes available for buffering in the client.
  78   uint32_t available_buffer_capacity_;
  79
  80   // Whether sending is paused due to an error.
  81   bool paused_;
  82
  83   // Whether we have encountered a fatal error and shut down.
  84   bool shut_down_;
  85
  86   base::WeakPtrFactory<DataSourceSender> weak_factory_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(DataSourceSender);
  89 };
  90
  91 }  // namespace device
  92
  93 #endif  // DEVICE_SERIAL_DATA_SOURCE_SENDER_H_