Improve speed of dump_connections() in layer_impl.h

nestkernel/layer_impl.h

@@ -309,48 +309,53 @@ Layer< D >::dump_connections( std::ostream& out,
   DictionaryDatum conn_filter( new Dictionary );
   def( conn_filter, names::synapse_model, syn_model );
   def( conn_filter, names::target, NodeCollectionDatum( target_layer->get_node_collection() ) );
+  def( conn_filter, names::source, NodeCollectionDatum( node_collection ) );
 
-  // Avoid setting up new array for each iteration of the loop
-  std::vector< size_t > source_array( 1 );
+  ArrayDatum connectome = kernel().connection_manager.get_connections( conn_filter );
 
-  for ( typename std::vector< std::pair< Position< D >, size_t > >::iterator src_iter = src_vec->begin();
-        src_iter != src_vec->end();
-        ++src_iter )
+  // Get variables for loop
+  size_t previous_source_node_id = getValue< ConnectionDatum >( connectome.get( 0 ) ).get_source_node_id();
+  Position< D > source_pos = src_vec->begin()->first;
+
+  // Print information about all local connections for current source
+  for ( size_t i = 0; i < connectome.size(); ++i )
   {
+    ConnectionDatum con_id = getValue< ConnectionDatum >( connectome.get( i ) );
+    const size_t source_node_id = con_id.get_source_node_id();
 
-    const size_t source_node_id = src_iter->second;
-    const Position< D > source_pos = src_iter->first;
+    // Search source_pos for source node only if it is a different node
+    if ( source_node_id != previous_source_node_id )
+    {
+      source_pos = src_vec->begin()->first;
 
-    source_array[ 0 ] = source_node_id;
-    def( conn_filter, names::source, NodeCollectionDatum( NodeCollection::create( source_array ) ) );
-    ArrayDatum connectome = kernel().connection_manager.get_connections( conn_filter );
+      for ( typename std::vector< std::pair< Position< D >, size_t > >::iterator src_iter = src_vec->begin();
+            ( src_iter != src_vec->end() ) && ( source_node_id != src_iter->second );
+            ++src_iter, source_pos = src_iter->first )
+        ;
 
-    // Print information about all local connections for current source
-    for ( size_t i = 0; i < connectome.size(); ++i )
-    {
-      ConnectionDatum con_id = getValue< ConnectionDatum >( connectome.get( i ) );
-      DictionaryDatum result_dict = kernel().connection_manager.get_synapse_status( con_id.get_source_node_id(),
-        con_id.get_target_node_id(),
-        con_id.get_target_thread(),
-        con_id.get_synapse_model_id(),
-        con_id.get_port() );
-
-      long target_node_id = getValue< long >( result_dict, names::target );
-      double weight = getValue< double >( result_dict, names::weight );
-      double delay = getValue< double >( result_dict, names::delay );
-
-      // Print source, target, weight, delay, rports
-      out << source_node_id << ' ' << target_node_id << ' ' << weight << ' ' << delay;
-
-      Layer< D >* tgt_layer = dynamic_cast< Layer< D >* >( target_layer.get() );
-
-      out << ' ';
-      const long tnode_lid = tgt_layer->node_collection_->get_lid( target_node_id );
-      assert( tnode_lid >= 0 );
-      tgt_layer->compute_displacement( source_pos, tnode_lid ).print( out );
-      out << '\n';
+      previous_source_node_id = source_node_id;
     }
-  }
+
+    DictionaryDatum result_dict = kernel().connection_manager.get_synapse_status( source_node_id,
+      con_id.get_target_node_id(),
+      con_id.get_target_thread(),
+      con_id.get_synapse_model_id(),
+      con_id.get_port() );
+
+    long target_node_id = getValue< long >( result_dict, names::target );
+    double weight = getValue< double >( result_dict, names::weight );
+    double delay = getValue< double >( result_dict, names::delay );
+
+    // Print source, target, weight, delay, rports
+    out << source_node_id << ' ' << target_node_id << ' ' << weight << ' ' << delay;
+
+    Layer< D >* tgt_layer = dynamic_cast< Layer< D >* >( target_layer.get() );
+
+    out << ' ';
+    const long tnode_lid = tgt_layer->node_collection_->get_lid( target_node_id );
+    assert( tnode_lid >= 0 );
+    tgt_layer->compute_displacement( source_pos, tnode_lid ).print( out );
+    out << '\n';
 }
 
 template < int D >