device/serial/data_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_SENDER_H_
   6 #define DEVICE_SERIAL_DATA_SENDER_H_
   7
   8 #include <queue>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/linked_ptr.h"
  12 #include "base/strings/string_piece.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 DataSender sends data to a DataSink.
  20 class DataSender : public serial::DataSinkClient, public mojo::ErrorHandler {
  21  public:
  22   typedef base::Callback<void(uint32_t bytes_sent)> DataSentCallback;
  23   typedef base::Callback<void(uint32_t bytes_sent, int32_t error)>
  24       SendErrorCallback;
  25   typedef base::Callback<void()> CancelCallback;
  26
  27   // Constructs a DataSender to send data to |sink|, using a buffer size of
  28   // |buffer_size|, with connection errors reported as |fatal_error_value|.
  29   DataSender(mojo::InterfacePtr<serial::DataSink> sink,
  30              uint32_t buffer_size,
  31              int32_t fatal_error_value);
  32
  33   ~DataSender() override;
  34
  35   // Starts an asynchronous send of |data|. If the send completes successfully,
  36   // |callback| will be called. Otherwise, |error_callback| will be called with
  37   // the error. If there is a cancel in progress or there has been a connection
  38   // error, this will not start a send and returns false. It is the caller's
  39   // responsibility to ensure |data| remains valid until one of |callback| and
  40   // |error_callback| is called.
  41   bool Send(const base::StringPiece& data,
  42             const DataSentCallback& callback,
  43             const SendErrorCallback& error_callback);
  44
  45   // Requests the cancellation of any in-progress sends. Calls to Send() will
  46   // fail until |callback| is called.
  47   bool Cancel(int32_t error, const CancelCallback& callback);
  48
  49  private:
  50   class PendingSend;
  51
  52   // serial::DataSinkClient overrides.
  53   void ReportBytesSent(uint32_t bytes_sent) override;
  54   void ReportBytesSentAndError(uint32_t bytes_sent,
  55                                int32_t error,
  56                                const mojo::Callback<void()>& callback) override;
  57
  58   // mojo::ErrorHandler override.
  59   void OnConnectionError() override;
  60
  61   // Sends up to |available_buffer_capacity_| bytes of data from
  62   // |pending_sends_| to |sink_|. When a PendingSend in |pending_sends_| has
  63   // been fully copied transmitted to |sink_|, it moves to
  64   // |sends_awaiting_ack_|.
  65   void SendInternal();
  66
  67   // Dispatches a cancel callback if one is pending.
  68   void RunCancelCallback();
  69
  70   // Shuts down this DataSender and dispatches fatal errors to all pending
  71   // operations.
  72   void ShutDown();
  73
  74   // The control connection to the data sink.
  75   mojo::InterfacePtr<serial::DataSink> sink_;
  76
  77   // The error value to report in the event of a fatal error.
  78   const int32_t fatal_error_value_;
  79
  80   // A queue of PendingSend that have not yet been fully sent to |sink_|.
  81   std::queue<linked_ptr<PendingSend> > pending_sends_;
  82
  83   // A queue of PendingSend that have been sent to |sink_|, but have not yet
  84   // been acked by the DataSink.
  85   std::queue<linked_ptr<PendingSend> > sends_awaiting_ack_;
  86
  87   // The callback to report cancel completion if a cancel operation is in
  88   // progress.
  89   CancelCallback pending_cancel_;
  90
  91   // The number of bytes available for buffering in the DataSink.
  92   uint32_t available_buffer_capacity_;
  93
  94   // Whether we have encountered a fatal error and shut down.
  95   bool shut_down_;
  96
  97   DISALLOW_COPY_AND_ASSIGN(DataSender);
  98 };
  99
 100 }  // namespace device
 101
 102 #endif  // DEVICE_SERIAL_DATA_SENDER_H_