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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef TALK_BASE_ASYNCPACKETSOCKET_H_
     29 #define TALK_BASE_ASYNCPACKETSOCKET_H_
     30 
     31 #include "talk/base/dscp.h"
     32 #include "talk/base/sigslot.h"
     33 #include "talk/base/socket.h"
     34 #include "talk/base/timeutils.h"
     35 
     36 namespace talk_base {
     37 
     38 // This structure will have the information about when packet is actually
     39 // received by socket.
     40 struct PacketTime {
     41   PacketTime() : timestamp(-1), not_before(-1) {}
     42   PacketTime(int64 timestamp, int64 not_before)
     43       : timestamp(timestamp), not_before(not_before) {
     44   }
     45 
     46   int64 timestamp;  // Receive time after socket delivers the data.
     47   int64 not_before; // Earliest possible time the data could have arrived,
     48                     // indicating the potential error in the |timestamp| value,
     49                     // in case the system, is busy. For example, the time of
     50                     // the last select() call.
     51                     // If unknown, this value will be set to zero.
     52 };
     53 
     54 inline PacketTime CreatePacketTime(int64 not_before) {
     55   return PacketTime(TimeMicros(), not_before);
     56 }
     57 
     58 // Provides the ability to receive packets asynchronously. Sends are not
     59 // buffered since it is acceptable to drop packets under high load.
     60 class AsyncPacketSocket : public sigslot::has_slots<> {
     61  public:
     62   enum State {
     63     STATE_CLOSED,
     64     STATE_BINDING,
     65     STATE_BOUND,
     66     STATE_CONNECTING,
     67     STATE_CONNECTED
     68   };
     69 
     70   AsyncPacketSocket() { }
     71   virtual ~AsyncPacketSocket() { }
     72 
     73   // Returns current local address. Address may be set to NULL if the
     74   // socket is not bound yet (GetState() returns STATE_BINDING).
     75   virtual SocketAddress GetLocalAddress() const = 0;
     76 
     77   // Returns remote address. Returns zeroes if this is not a client TCP socket.
     78   virtual SocketAddress GetRemoteAddress() const = 0;
     79 
     80   // Send a packet.
     81   virtual int Send(const void *pv, size_t cb, DiffServCodePoint dscp) = 0;
     82   virtual int SendTo(const void *pv, size_t cb, const SocketAddress& addr,
     83                      DiffServCodePoint) = 0;
     84 
     85   // Close the socket.
     86   virtual int Close() = 0;
     87 
     88   // Returns current state of the socket.
     89   virtual State GetState() const = 0;
     90 
     91   // Get/set options.
     92   virtual int GetOption(Socket::Option opt, int* value) = 0;
     93   virtual int SetOption(Socket::Option opt, int value) = 0;
     94 
     95   // Get/Set current error.
     96   // TODO: Remove SetError().
     97   virtual int GetError() const = 0;
     98   virtual void SetError(int error) = 0;
     99 
    100   // Emitted each time a packet is read. Used only for UDP and
    101   // connected TCP sockets.
    102   sigslot::signal5<AsyncPacketSocket*, const char*, size_t,
    103                    const SocketAddress&,
    104                    const PacketTime&> SignalReadPacket;
    105 
    106   // Emitted when the socket is currently able to send.
    107   sigslot::signal1<AsyncPacketSocket*> SignalReadyToSend;
    108 
    109   // Emitted after address for the socket is allocated, i.e. binding
    110   // is finished. State of the socket is changed from BINDING to BOUND
    111   // (for UDP and server TCP sockets) or CONNECTING (for client TCP
    112   // sockets).
    113   sigslot::signal2<AsyncPacketSocket*, const SocketAddress&> SignalAddressReady;
    114 
    115   // Emitted for client TCP sockets when state is changed from
    116   // CONNECTING to CONNECTED.
    117   sigslot::signal1<AsyncPacketSocket*> SignalConnect;
    118 
    119   // Emitted for client TCP sockets when state is changed from
    120   // CONNECTED to CLOSED.
    121   sigslot::signal2<AsyncPacketSocket*, int> SignalClose;
    122 
    123   // Used only for listening TCP sockets.
    124   sigslot::signal2<AsyncPacketSocket*, AsyncPacketSocket*> SignalNewConnection;
    125 
    126  private:
    127   DISALLOW_EVIL_CONSTRUCTORS(AsyncPacketSocket);
    128 };
    129 
    130 }  // namespace talk_base
    131 
    132 #endif  // TALK_BASE_ASYNCPACKETSOCKET_H_
    133