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      1 // Copyright (c) 2010 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 NET_SOCKET_CLIENT_SOCKET_H_
      6 #define NET_SOCKET_CLIENT_SOCKET_H_
      7 #pragma once
      8 
      9 #include "net/base/net_log.h"
     10 #include "net/socket/socket.h"
     11 
     12 namespace net {
     13 
     14 class AddressList;
     15 class IPEndPoint;
     16 
     17 class ClientSocket : public Socket {
     18  public:
     19   virtual ~ClientSocket() {}
     20 
     21   // Called to establish a connection.  Returns OK if the connection could be
     22   // established synchronously.  Otherwise, ERR_IO_PENDING is returned and the
     23   // given callback will run asynchronously when the connection is established
     24   // or when an error occurs.  The result is some other error code if the
     25   // connection could not be established.
     26   //
     27   // The socket's Read and Write methods may not be called until Connect
     28   // succeeds.
     29   //
     30   // It is valid to call Connect on an already connected socket, in which case
     31   // OK is simply returned.
     32   //
     33   // Connect may also be called again after a call to the Disconnect method.
     34   //
     35   virtual int Connect(CompletionCallback* callback
     36 #ifdef ANDROID
     37                       , bool wait_for_connect
     38                       , bool valid_uid
     39                       , uid_t calling_uid
     40 #endif
     41                      ) = 0;
     42 
     43   // Called to disconnect a socket.  Does nothing if the socket is already
     44   // disconnected.  After calling Disconnect it is possible to call Connect
     45   // again to establish a new connection.
     46   //
     47   // If IO (Connect, Read, or Write) is pending when the socket is
     48   // disconnected, the pending IO is cancelled, and the completion callback
     49   // will not be called.
     50   virtual void Disconnect() = 0;
     51 
     52   // Called to test if the connection is still alive.  Returns false if a
     53   // connection wasn't established or the connection is dead.
     54   virtual bool IsConnected() const = 0;
     55 
     56   // Called to test if the connection is still alive and idle.  Returns false
     57   // if a connection wasn't established, the connection is dead, or some data
     58   // have been received.
     59   virtual bool IsConnectedAndIdle() const = 0;
     60 
     61   // Copies the peer address to |address| and returns a network error code.
     62   // ERR_SOCKET_NOT_CONNECTED will be returned if the socket is not connected.
     63   // TODO(sergeyu): Use IPEndPoint instead of AddressList.
     64   virtual int GetPeerAddress(AddressList* address) const = 0;
     65 
     66   // Copies the local address to |address| and returns a network error code.
     67   // ERR_SOCKET_NOT_CONNECTED will be returned if the socket is not connected.
     68   virtual int GetLocalAddress(IPEndPoint* address) const = 0;
     69 
     70   // Gets the NetLog for this socket.
     71   virtual const BoundNetLog& NetLog() const = 0;
     72 
     73   // Set the annotation to indicate this socket was created for speculative
     74   // reasons.  This call is generally forwarded to a basic TCPClientSocket*,
     75   // where a UseHistory can be updated.
     76   virtual void SetSubresourceSpeculation() = 0;
     77   virtual void SetOmniboxSpeculation() = 0;
     78 
     79   // Returns true if the underlying transport socket ever had any reads or
     80   // writes.  ClientSockets layered on top of transport sockets should forward
     81   // this call to the transport socket.
     82   virtual bool WasEverUsed() const = 0;
     83 
     84   // Returns true if the underlying transport socket is using TCP FastOpen.
     85   // TCP FastOpen is an experiment with sending data in the TCP SYN packet.
     86   virtual bool UsingTCPFastOpen() const = 0;
     87 
     88  protected:
     89   // The following class is only used to gather statistics about the history of
     90   // a socket.  It is only instantiated and used in basic sockets, such as
     91   // TCPClientSocket* instances.  Other classes that are derived from
     92   // ClientSocket should forward any potential settings to their underlying
     93   // transport sockets.
     94   class UseHistory {
     95    public:
     96     UseHistory();
     97     ~UseHistory();
     98 
     99     // Resets the state of UseHistory and emits histograms for the
    100     // current state.
    101     void Reset();
    102 
    103     void set_was_ever_connected();
    104     void set_was_used_to_convey_data();
    105 
    106     // The next two setters only have any impact if the socket has not yet been
    107     // used to transmit data.  If called later, we assume that the socket was
    108     // reused from the pool, and was NOT constructed to service a speculative
    109     // request.
    110     void set_subresource_speculation();
    111     void set_omnibox_speculation();
    112 
    113     bool was_used_to_convey_data() const;
    114 
    115    private:
    116     // Summarize the statistics for this socket.
    117     void EmitPreconnectionHistograms() const;
    118     // Indicate if this was ever connected.
    119     bool was_ever_connected_;
    120     // Indicate if this socket was ever used to transmit or receive data.
    121     bool was_used_to_convey_data_;
    122 
    123     // Indicate if this socket was first created for speculative use, and
    124     // identify the motivation.
    125     bool omnibox_speculation_;
    126     bool subresource_speculation_;
    127     DISALLOW_COPY_AND_ASSIGN(UseHistory);
    128   };
    129 
    130   // Logs a SOCKET_BYTES_RECEIVED or SOCKET_BYTES_SENT event to the NetLog.
    131   // Determines whether to log the received bytes or not, based on the current
    132   // logging level.
    133   void LogByteTransfer(const BoundNetLog& net_log, NetLog::EventType event_type,
    134                        int byte_count, char* bytes) const;
    135 };
    136 
    137 }  // namespace net
    138 
    139 #endif  // NET_SOCKET_CLIENT_SOCKET_H_
    140