device/serial/data_sink_receiver.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_SINK_RECEIVER_H_
   6 #define DEVICE_SERIAL_DATA_SINK_RECEIVER_H_
   7
   8 #include <queue>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/linked_ptr.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "device/serial/buffer.h"
  15 #include "device/serial/data_stream.mojom.h"
  16 #include "third_party/mojo/src/mojo/public/cpp/system/data_pipe.h"
  17
  18 namespace device {
  19
  20 class DataSinkReceiver : public base::RefCounted<DataSinkReceiver>,
  21                          public serial::DataSink,
  22                          public mojo::ErrorHandler {
  23  public:
  24   typedef base::Callback<void(scoped_ptr<ReadOnlyBuffer>)> ReadyCallback;
  25   typedef base::Callback<void(int32_t error)> CancelCallback;
  26   typedef base::Callback<void()> ErrorCallback;
  27
  28   // Constructs a DataSinkReceiver. Whenever the pipe is ready for reading, the
  29   // |ready_callback| will be called with the ReadOnlyBuffer to read.
  30   // |ready_callback| will not be called again until the previous ReadOnlyBuffer
  31   // is destroyed. If a connection error occurs, |error_callback| will be called
  32   // and the DataSinkReceiver will act as if ShutDown() had been called. If
  33   // |cancel_callback| is valid, it will be called when the DataSink client
  34   // requests cancellation of the in-progress read.
  35   DataSinkReceiver(mojo::InterfaceRequest<serial::DataSink> request,
  36                    const ReadyCallback& ready_callback,
  37                    const CancelCallback& cancel_callback,
  38                    const ErrorCallback& error_callback);
  39
  40   // Shuts down this DataSinkReceiver. After shut down, |ready_callback|,
  41   // |cancel_callback| and |error_callback| will never be called.
  42   void ShutDown();
  43
  44  private:
  45   class Buffer;
  46   class DataFrame;
  47   friend class base::RefCounted<DataSinkReceiver>;
  48
  49   ~DataSinkReceiver() override;
  50
  51   // mojo::InterfaceImpl<serial::DataSink> overrides.
  52   void Cancel(int32_t error) override;
  53   void OnData(mojo::Array<uint8_t> data,
  54               const mojo::Callback<void(uint32_t, int32_t)>& callback) override;
  55   void ClearError() override;
  56
  57   void OnConnectionError() override;
  58
  59   // Dispatches data to |ready_callback_|.
  60   void RunReadyCallback();
  61
  62   // Reports a successful read of |bytes_read|.
  63   void Done(uint32_t bytes_read);
  64
  65   // Reports a partially successful or unsuccessful read of |bytes_read|
  66   // with an error of |error|.
  67   void DoneWithError(uint32_t bytes_read, int32_t error);
  68
  69   // Marks |bytes_read| bytes as being read.
  70   bool DoneInternal(uint32_t bytes_read);
  71
  72   // Reports an error to the client.
  73   void ReportError(uint32_t bytes_read, int32_t error);
  74
  75   // Reports a fatal error to the client and shuts down.
  76   void DispatchFatalError();
  77
  78   mojo::Binding<serial::DataSink> binding_;
  79
  80   // The callback to call when there is data ready to read.
  81   const ReadyCallback ready_callback_;
  82
  83   // The callback to call when the client has requested cancellation.
  84   const CancelCallback cancel_callback_;
  85
  86   // The callback to call if a fatal error occurs.
  87   const ErrorCallback error_callback_;
  88
  89   // The current error that has not been cleared by a ClearError message..
  90   int32_t current_error_;
  91
  92   // The buffer passed to |ready_callback_| if one exists. This is not owned,
  93   // but the Buffer will call Done or DoneWithError before being deleted.
  94   Buffer* buffer_in_use_;
  95
  96   // The data we have received from the client that has not been passed to
  97   // |ready_callback_|.
  98   std::queue<linked_ptr<DataFrame>> pending_data_buffers_;
  99
 100   // Whether we have encountered a fatal error and shut down.
 101   bool shut_down_;
 102
 103   base::WeakPtrFactory<DataSinkReceiver> weak_factory_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(DataSinkReceiver);
 106 };
 107
 108 }  // namespace device
 109
 110 #endif  // DEVICE_SERIAL_DATA_SINK_RECEIVER_H_