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:
  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 DataSink client
  33   // requests cancellation of the in-progress read.
  34   DataSinkReceiver(mojo::InterfaceRequest<serial::DataSink> request,
  35                    const ReadyCallback& ready_callback,
  36                    const CancelCallback& cancel_callback,
  37                    const ErrorCallback& error_callback);
  38
  39   // Shuts down this DataSinkReceiver. After shut down, |ready_callback|,
  40   // |cancel_callback| and |error_callback| will never be called.
  41   void ShutDown();
  42
  43  private:
  44   class Buffer;
  45   class DataFrame;
  46   friend class base::RefCounted<DataSinkReceiver>;
  47
  48   ~DataSinkReceiver() override;
  49
  50   // mojo::InterfaceImpl<serial::DataSink> overrides.
  51   void Cancel(int32_t error) override;
  52   void OnData(mojo::Array<uint8_t> data,
  53               const mojo::Callback<void(uint32_t, int32_t)>& callback) override;
  54   void ClearError() override;
  55
  56   void OnConnectionError();
  57
  58   // Dispatches data to |ready_callback_|.
  59   void RunReadyCallback();
  60
  61   // Reports a successful read of |bytes_read|.
  62   void Done(uint32_t bytes_read);
  63
  64   // Reports a partially successful or unsuccessful read of |bytes_read|
  65   // with an error of |error|.
  66   void DoneWithError(uint32_t bytes_read, int32_t error);
  67
  68   // Marks |bytes_read| bytes as being read.
  69   bool DoneInternal(uint32_t bytes_read);
  70
  71   // Reports an error to the client.
  72   void ReportError(uint32_t bytes_read, int32_t error);
  73
  74   // Reports a fatal error to the client and shuts down.
  75   void DispatchFatalError();
  76
  77   mojo::Binding<serial::DataSink> binding_;
  78
  79   // The callback to call when there is data ready to read.
  80   const ReadyCallback ready_callback_;
  81
  82   // The callback to call when the client has requested cancellation.
  83   const CancelCallback cancel_callback_;
  84
  85   // The callback to call if a fatal error occurs.
  86   const ErrorCallback error_callback_;
  87
  88   // The current error that has not been cleared by a ClearError message..
  89   int32_t current_error_;
  90
  91   // The buffer passed to |ready_callback_| if one exists. This is not owned,
  92   // but the Buffer will call Done or DoneWithError before being deleted.
  93   Buffer* buffer_in_use_;
  94
  95   // The data we have received from the client that has not been passed to
  96   // |ready_callback_|.
  97   std::queue<linked_ptr<DataFrame>> pending_data_buffers_;
  98
  99   // Whether we have encountered a fatal error and shut down.
 100   bool shut_down_;
 101
 102   base::WeakPtrFactory<DataSinkReceiver> weak_factory_;
 103
 104   DISALLOW_COPY_AND_ASSIGN(DataSinkReceiver);
 105 };
 106
 107 }  // namespace device
 108
 109 #endif  // DEVICE_SERIAL_DATA_SINK_RECEIVER_H_