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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_NETWORK_H_
     29 #define TALK_BASE_NETWORK_H_
     30 
     31 #include <deque>
     32 #include <map>
     33 #include <string>
     34 #include <vector>
     35 
     36 #include "talk/base/basictypes.h"
     37 
     38 namespace talk_base {
     39 
     40 class Network;
     41 class NetworkSession;
     42 
     43 // Keeps track of the available network interfaces over time so that quality
     44 // information can be aggregated and recorded.
     45 class NetworkManager {
     46  public:
     47   virtual ~NetworkManager();
     48 
     49   // Updates and returns the current list of networks available on this machine.
     50   // This version will make sure that repeated calls return the same object for
     51   // a given network, so that quality is tracked appropriately.
     52   // Does not include ignored networks.
     53   bool GetNetworks(std::vector<Network*>* networks);
     54 
     55   // Logs the available networks.
     56   void DumpNetworks(bool include_ignored);
     57 
     58   // Reads and writes the state of the quality database in a string format.
     59   std::string GetState() const;
     60   void SetState(const std::string& str);
     61 
     62   // Creates a network object for each network available on the machine.
     63   static bool CreateNetworks(bool include_ignored,
     64                              std::vector<Network*>* networks);
     65   // Determines if a network should be ignored.
     66   static bool IsIgnoredNetwork(const Network& network);
     67 
     68  protected:
     69   // Fills the supplied list with all usable networks. Overrideable.
     70   virtual bool EnumNetworks(bool include_ignored,
     71                             std::vector<Network*>* networks);
     72 
     73  private:
     74   typedef std::map<std::string, Network*> NetworkMap;
     75 
     76   NetworkMap networks_;
     77 };
     78 
     79 // Represents a Unix-type network interface, with a name and single address.
     80 // It also includes the ability to track and estimate quality.
     81 class Network {
     82  public:
     83   Network(const std::string& name, const std::string& description,
     84           uint32 ip, uint32 gateway_ip);
     85 
     86   // Returns the index of this network.  This is considered the primary key
     87   // that identifies each network.
     88   const std::string& name() const { return name_; }
     89 
     90   // Returns the OS-assigned name for this network. This is useful for
     91   // debugging but should not be sent over the wire (for privacy reasons).
     92   const std::string& description() const { return description_; }
     93 
     94   // Identifies the current IP address used by this network.
     95   uint32 ip() const { return ip_; }
     96   void set_ip(uint32 ip) { ip_ = ip; }
     97 
     98   // Identifies the current gateway IP address used by this network.
     99   uint32 gateway_ip() const { return gateway_ip_; }
    100   void set_gateway_ip(uint32 ip) { gateway_ip_ = ip; }
    101 
    102   // Indicates whether this network should be ignored, perhaps because the
    103   // IP/gateway is 0, or the interface is one we know is invalid.
    104   bool ignored() const { return ignored_; }
    105   void set_ignored(bool ignored) { ignored_ = ignored; }
    106 
    107   // Updates the list of sessions that are ongoing.
    108   void StartSession(NetworkSession* session);
    109   void StopSession(NetworkSession* session);
    110 
    111   // Re-computes the estimate of near-future quality based on the information
    112   // as of this exact moment.
    113   void EstimateQuality();
    114 
    115   // Returns the current estimate of the near-future quality of connections
    116   // that use this local interface.
    117   double quality() { return quality_; }
    118 
    119   // Debugging description of this network
    120   std::string ToString() const;
    121 
    122  private:
    123   typedef std::vector<NetworkSession*> SessionList;
    124 
    125   std::string name_;
    126   std::string description_;
    127   uint32 ip_;
    128   uint32 gateway_ip_;
    129   bool ignored_;
    130   SessionList sessions_;
    131   double uniform_numerator_;
    132   double uniform_denominator_;
    133   double exponential_numerator_;
    134   double exponential_denominator_;
    135   uint32 last_data_time_;
    136   double quality_;
    137 
    138   // Updates the statistics maintained to include the given estimate.
    139   void AddDataPoint(uint32 time, double quality);
    140 
    141   // Converts the internal state to and from a string.  This is used to record
    142   // quality information into a permanent store.
    143   void SetState(const std::string& str);
    144   std::string GetState() const;
    145 
    146   friend class NetworkManager;
    147 };
    148 
    149 // Represents a session that is in progress using a particular network and can
    150 // provide data about the quality of the network at any given moment.
    151 class NetworkSession {
    152  public:
    153   virtual ~NetworkSession() { }
    154 
    155   // Determines whether this session has an estimate at this moment.  We will
    156   // only call GetCurrentQuality when this returns true.
    157   virtual bool HasQuality() = 0;
    158 
    159   // Returns an estimate of the quality at this exact moment.  The result should
    160   // be a MOS (mean opinion score) value.
    161   virtual float GetCurrentQuality() = 0;
    162 };
    163 
    164 const double QUALITY_BAD  = 3.0;
    165 const double QUALITY_FAIR = 3.35;
    166 const double QUALITY_GOOD = 3.7;
    167 
    168 }  // namespace talk_base
    169 
    170 #endif  // TALK_BASE_NETWORK_H_
    171