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 AsyncWaiter;
  21
  22 class DataSinkReceiver : public base::RefCounted<DataSinkReceiver>,
  23                          public mojo::InterfaceImpl<serial::DataSink> {
  24  public:
  25   typedef base::Callback<void(scoped_ptr<ReadOnlyBuffer>)> ReadyCallback;
  26   typedef base::Callback<void(int32_t error)> CancelCallback;
  27   typedef base::Callback<void()> ErrorCallback;
  28
  29   // Constructs a DataSinkReceiver. Whenever the pipe is ready for reading, the
  30   // |ready_callback| will be called with the ReadOnlyBuffer to read.
  31   // |ready_callback| will not be called again until the previous ReadOnlyBuffer
  32   // is destroyed. If a connection error occurs, |error_callback| will be called
  33   // and the DataSinkReceiver will act as if ShutDown() had been called. If
  34   // |cancel_callback| is valid, it will be called when the DataSinkClient
  35   // requests cancellation of the in-progress read.
  36   DataSinkReceiver(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 PendingFlush;
  47   friend class base::RefCounted<DataSinkReceiver>;
  48
  49   ~DataSinkReceiver() override;
  50
  51   // mojo::InterfaceImpl<serial::DataSink> overrides.
  52   void Init(mojo::ScopedDataPipeConsumerHandle handle) override;
  53   void Cancel(int32_t error) override;
  54   void OnConnectionError() override;
  55
  56   // Starts waiting for |handle_| to be ready for reads.
  57   void StartWaiting();
  58
  59   // Invoked when |handle_| is ready for reads.
  60   void OnDoneWaiting(MojoResult result);
  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   // Finishes the two-phase data pipe read.
  70   bool DoneInternal(uint32_t bytes_read);
  71
  72   // Sends an ReportBytesSentAndError message to the client.
  73   void ReportBytesSentAndError(uint32_t bytes_read, int32_t error);
  74
  75   // Invoked in response to an ReportBytesSentAndError call to the client with
  76   // the number of bytes to flush.
  77   void SetNumBytesToFlush(uint32_t bytes_to_flush);
  78
  79   // Reports a fatal error to the client and shuts down.
  80   void DispatchFatalError();
  81
  82   // The data connection to the data sender.
  83   mojo::ScopedDataPipeConsumerHandle handle_;
  84
  85   // The callback to call when |handle_| has data ready to read.
  86   const ReadyCallback ready_callback_;
  87
  88   // The callback to call when the client has requested cancellation.
  89   const CancelCallback cancel_callback_;
  90
  91   // The callback to call if a fatal error occurs.
  92   const ErrorCallback error_callback_;
  93
  94   // The queue of pending flushes.
  95   std::queue<linked_ptr<PendingFlush> > pending_flushes_;
  96
  97   // A waiter used to wait until |handle_| is readable if we are waiting.
  98   scoped_ptr<AsyncWaiter> waiter_;
  99
 100   // The buffer passed to |ready_callback_| if one exists. This is not owned,
 101   // but the Buffer will call Done or DoneWithError before being deleted.
 102   Buffer* buffer_in_use_;
 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_