media/mtransport/transportlayer.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 // Original author: ekr@rtfm.com
   8
   9 #ifndef transportlayer_h__
  10 #define transportlayer_h__
  11
  12 #include "sigslot.h"
  13
  14 #include "mozilla/DebugOnly.h"
  15 #include "mozilla/RefPtr.h"
  16 #include "nsCOMPtr.h"
  17 #include "nsIEventTarget.h"
  18
  19 #include "m_cpp_utils.h"
  20
  21 namespace mozilla {
  22
  23 class TransportFlow;
  24
  25 typedef int TransportResult;
  26
  27 enum {
  28   TE_WOULDBLOCK = -1, TE_ERROR = -2, TE_INTERNAL = -3
  29 };
  30
  31 #define TRANSPORT_LAYER_ID(name) \
  32   virtual const std::string id() const { return name; } \
  33   static std::string ID() { return name; }
  34
  35 // Abstract base class for network transport layers.
  36 class TransportLayer : public sigslot::has_slots<> {
  37  public:
  38   // The state of the transport flow
  39   // We can't use "ERROR" because Windows has a macro named "ERROR"
  40   enum State { TS_NONE, TS_INIT, TS_CONNECTING, TS_OPEN, TS_CLOSED, TS_ERROR };
  41
  42   // Is this a stream or datagram flow
  43   TransportLayer() :
  44     state_(TS_NONE),
  45     flow_id_(),
  46     downward_(nullptr) {}
  47
  48   virtual ~TransportLayer() {}
  49
  50   // Called to initialize
  51   nsresult Init();  // Called by Insert() to set up -- do not override
  52   virtual nsresult InitInternal() { return NS_OK; } // Called by Init
  53
  54   // Called when inserted into a flow
  55   virtual void Inserted(TransportFlow *flow, TransportLayer *downward);
  56
  57   // Downward interface
  58   TransportLayer *downward() { return downward_; }
  59
  60   // Dispatch a call onto our thread (or run on the same thread if
  61   // thread is not set). This is always synchronous.
  62   nsresult RunOnThread(nsIRunnable *event);
  63
  64   // Get the state
  65   State state() const { return state_; }
  66   // Must be implemented by derived classes
  67   virtual TransportResult SendPacket(const unsigned char *data, size_t len) = 0;
  68
  69   // Get the thread.
  70   const nsCOMPtr<nsIEventTarget> GetThread() const {
  71     return target_;
  72   }
  73
  74   // Event definitions that one can register for
  75   // State has changed
  76   sigslot::signal2<TransportLayer*, State> SignalStateChange;
  77   // Data received on the flow
  78   sigslot::signal3<TransportLayer*, const unsigned char *, size_t>
  79                          SignalPacketReceived;
  80
  81   // Return the layer id for this layer
  82   virtual const std::string id() const = 0;
  83
  84   // The id of the flow
  85   const std::string& flow_id() const {
  86     return flow_id_;
  87   }
  88
  89  protected:
  90   virtual void WasInserted() {}
  91   virtual void SetState(State state, const char *file, unsigned line);
  92   // Check if we are on the right thread
  93   void CheckThread() const {
  94     NS_ABORT_IF_FALSE(CheckThreadInt(), "Wrong thread");
  95   }
  96
  97   State state_;
  98   std::string flow_id_;
  99   TransportLayer *downward_; // The next layer in the stack
 100   nsCOMPtr<nsIEventTarget> target_;
 101
 102  private:
 103   DISALLOW_COPY_ASSIGN(TransportLayer);
 104
 105   bool CheckThreadInt() const {
 106     bool on;
 107
 108     if (!target_)  // OK if no thread set.
 109       return true;
 110
 111     NS_ENSURE_SUCCESS(target_->IsOnCurrentThread(&on), false);
 112     NS_ENSURE_TRUE(on, false);
 113
 114     return true;
 115   }
 116 };
 117
 118 #define LAYER_INFO "Flow[" << flow_id() << "(none)" << "]; Layer[" << id() << "]: "
 119 #define TL_SET_STATE(x) SetState((x), __FILE__, __LINE__)
 120
 121 }  // close namespace
 122 #endif