OLSR optimization: avoid doing routing table computation if no local DB changed after receiving a OLSR packet.

src/routing/olsr/olsr-agent-impl.cc

@@ -350,6 +350,8 @@ AgentImpl::RecvOlsr (Ptr<Socket> socket,
 
   m_rxPacketTrace (olsrPacketHeader, messages);
 
+  m_state.SetModified (false);
+
   for (MessageList::const_iterator messageIter = messages.begin ();
        messageIter != messages.end (); messageIter++)
     {
@@ -446,7 +448,11 @@ AgentImpl::RecvOlsr (Ptr<Socket> socket,
     }
 
   // After processing all OLSR messages, we must recompute the routing table
-  RoutingTableComputation ();
+  if (m_state.GetModified ())
+    {
+      RoutingTableComputation ();
+      m_state.SetModified (false);
+    }
 }
 
 ///

src/routing/olsr/olsr-state.cc

@@ -127,6 +127,7 @@ OlsrState::EraseNeighborTuple (const NeighborTuple &tuple)
       if (*it == tuple)
         {
           m_neighborSet.erase (it);
+          m_modified = true;
           break;
         }
     }
@@ -141,6 +142,7 @@ OlsrState::EraseNeighborTuple (const Ipv4Address &mainAddr)
       if (it->neighborMainAddr == mainAddr)
         {
           it = m_neighborSet.erase (it);
+          m_modified = true;
           break;
         }
     }
@@ -156,6 +158,7 @@ OlsrState::InsertNeighborTuple (NeighborTuple const &tuple)
         {
           // Update it
           *it = tuple;
+          m_modified = true;
           return;
         }
     }
@@ -189,6 +192,7 @@ OlsrState::EraseTwoHopNeighborTuple (const TwoHopNeighborTuple &tuple)
       if (*it == tuple)
         {
           m_twoHopNeighborSet.erase(it);
+          m_modified = true;
           break;
         }
     }
@@ -206,6 +210,7 @@ OlsrState::EraseTwoHopNeighborTuples (const Ipv4Address &neighborMainAddr,
         {
           it = m_twoHopNeighborSet.erase (it);
           it--; // FIXME: is this correct in the case 'it' pointed to the first element?
+          m_modified = true;
         }
     }
 }
@@ -219,13 +224,16 @@ OlsrState::EraseTwoHopNeighborTuples (const Ipv4Address &neighborMainAddr)
       if (it->neighborMainAddr == neighborMainAddr) {
         it = m_twoHopNeighborSet.erase (it);
         it--;
+        m_modified = true;
       }
     }
 }
 
 void
-OlsrState::InsertTwoHopNeighborTuple (TwoHopNeighborTuple const &tuple){
+OlsrState::InsertTwoHopNeighborTuple (TwoHopNeighborTuple const &tuple)
+{
   m_twoHopNeighborSet.push_back (tuple);
+  m_modified = true;
 }
 
 /********** MPR Set Manipulation **********/
@@ -323,6 +331,7 @@ OlsrState::EraseLinkTuple (const LinkTuple &tuple)
       if (*it == tuple)
         {
           m_linkSet.erase (it);
+          m_modified = true;
           break;
         }
     }
@@ -332,6 +341,7 @@ LinkTuple&
 OlsrState::InsertLinkTuple (LinkTuple const &tuple)
 {
   m_linkSet.push_back (tuple);
+  m_modified = true;
   return m_linkSet.back ();
 }
 
@@ -371,6 +381,7 @@ OlsrState::EraseTopologyTuple(const TopologyTuple &tuple)
       if (*it == tuple)
         {
           m_topologySet.erase (it);
+          m_modified = true;
           break;
         }
     }
@@ -386,6 +397,7 @@ OlsrState::EraseOlderTopologyTuples (const Ipv4Address &lastAddr, uint16_t ansn)
         {
           it = m_topologySet.erase (it);
           it--;
+          m_modified = true;
         }
     }
 }
@@ -394,6 +406,7 @@ void
 OlsrState::InsertTopologyTuple (TopologyTuple const &tuple)
 {
   m_topologySet.push_back (tuple);
+  m_modified = true;
 }
 
 /********** Interface Association Set Manipulation **********/
@@ -431,6 +444,7 @@ OlsrState::EraseIfaceAssocTuple (const IfaceAssocTuple &tuple)
       if (*it == tuple)
         {
           m_ifaceAssocSet.erase (it);
+          m_modified = true;
           break;
         }
     }
@@ -440,6 +454,7 @@ void
 OlsrState::InsertIfaceAssocTuple (const IfaceAssocTuple &tuple)
 {
   m_ifaceAssocSet.push_back (tuple);
+  m_modified = true;
 }
 
 std::vector<Ipv4Address>

src/routing/olsr/olsr-state.h

@@ -46,8 +46,29 @@ protected:
   DuplicateSet m_duplicateSet;	///< Duplicate Set (RFC 3626, section 3.4).
   IfaceAssocSet m_ifaceAssocSet;	///< Interface Association Set (RFC 3626, section 4.1).
 
+// m_modified is set to true when any of the following databases is modified:
+//      -    the link set,
+//      -    the neighbor set,
+//      -    the 2-hop neighbor set,
+//      -    the topology set,
+//      -    the Multiple Interface Association Information Base,
+  bool m_modified;
+
 public:
 
+  OlsrState ()
+    : m_modified (false)
+  {}
+  
+  bool GetModified () const
+  {
+    return m_modified;
+  }
+  void SetModified (bool modified)
+  {
+    m_modified = modified;
+  }
+
   // MPR selector
   const MprSelectorSet & GetMprSelectors () const
   {