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 "mojo/public/cpp/system/data_pipe.h"
  17
  18 namespace device {
  19
  20 class DataSinkReceiver : public base::RefCounted<DataSinkReceiver>,
  21                          public mojo::InterfaceImpl<serial::DataSink> {
  22  public:
  23   typedef base::Callback<void(scoped_ptr<ReadOnlyBuffer>)> ReadyCallback;
  24   typedef base::Callback<void(int32_t error)> CancelCallback;
  25   typedef base::Callback<void()> ErrorCallback;
  26
  27   // Constructs a DataSinkReceiver. Whenever the pipe is ready for reading, the
  28   // |ready_callback| will be called with the ReadOnlyBuffer to read.
  29   // |ready_callback| will not be called again until the previous ReadOnlyBuffer
  30   // is destroyed. If a connection error occurs, |error_callback| will be called
  31   // and the DataSinkReceiver will act as if ShutDown() had been called. If
  32   // |cancel_callback| is valid, it will be called when the DataSinkClient
  33   // requests cancellation of the in-progress read.
  34   DataSinkReceiver(const ReadyCallback& ready_callback,
  35                    const CancelCallback& cancel_callback,
  36                    const ErrorCallback& error_callback);
  37
  38   // Shuts down this DataSinkReceiver. After shut down, |ready_callback|,
  39   // |cancel_callback| and |error_callback| will never be called.
  40   void ShutDown();
  41
  42  private:
  43   class Buffer;
  44   class DataFrame;
  45   friend class base::RefCounted<DataSinkReceiver>;
  46
  47   ~DataSinkReceiver() override;
  48
  49   // mojo::InterfaceImpl<serial::DataSink> overrides.
  50   void Init(uint32_t buffer_size) override;
  51   void Cancel(int32_t error) override;
  52   void OnData(mojo::Array<uint8_t> data) override;
  53   void OnConnectionError() override;
  54
  55   // Dispatches data to |ready_callback_|.
  56   void RunReadyCallback();
  57
  58   // Reports a successful read of |bytes_read|.
  59   void Done(uint32_t bytes_read);
  60
  61   // Reports a partially successful or unsuccessful read of |bytes_read|
  62   // with an error of |error|.
  63   void DoneWithError(uint32_t bytes_read, int32_t error);
  64
  65   // Marks |bytes_read| bytes as being read.
  66   bool DoneInternal(uint32_t bytes_read);
  67
  68   // Sends an ReportBytesSentAndError message to the client.
  69   void ReportBytesSentAndError(uint32_t bytes_read, int32_t error);
  70
  71   // Invoked in response to an ReportBytesSentAndError call to the client at
  72   // the point in the data stream to flush.
  73   void DoFlush();
  74
  75   // Reports a fatal error to the client and shuts down.
  76   void DispatchFatalError();
  77
  78   // The callback to call when there is data ready to read.
  79   const ReadyCallback ready_callback_;
  80
  81   // The callback to call when the client has requested cancellation.
  82   const CancelCallback cancel_callback_;
  83
  84   // The callback to call if a fatal error occurs.
  85   const ErrorCallback error_callback_;
  86
  87   // Whether we are waiting for a flush.
  88   bool flush_pending_;
  89
  90   // The buffer passed to |ready_callback_| if one exists. This is not owned,
  91   // but the Buffer will call Done or DoneWithError before being deleted.
  92   Buffer* buffer_in_use_;
  93
  94   // Whether this has received an Init() call from the client.
  95   bool initialized_;
  96
  97   // The remaining number of bytes of data that we can buffer.
  98   uint32_t available_buffer_capacity_;
  99
 100   // The data we have received from the client that has not been passed to
 101   // |ready_callback_|.
 102   std::queue<linked_ptr<DataFrame>> pending_data_buffers_;
 103
 104   // Whether we have encountered a fatal error and shut down.
 105   bool shut_down_;
 106
 107   base::WeakPtrFactory<DataSinkReceiver> weak_factory_;
 108
 109   DISALLOW_COPY_AND_ASSIGN(DataSinkReceiver);
 110 };
 111
 112 }  // namespace device
 113
 114 #endif  // DEVICE_SERIAL_DATA_SINK_RECEIVER_H_