Add stall on demand, but no real speedup

easbar · Apr 2, 2020 · 94c01eb · 94c01eb
1 parent c49e732
commit 94c01eb
Showing 1 changed file with 36 additions and 0 deletions.
diff --git a/src/path_calculator.rs b/src/path_calculator.rs
@@ -96,6 +96,10 @@ impl PathCalculator {
                 if curr.weight > best_weight {
                     break;
                 }
+                // stall on demand optimization
+                if self.is_stallable_fwd(graph, curr) {
+                    continue;
+                }
                 let begin = graph.begin_out_edges(curr.node_id);
                 let end = graph.end_out_edges(curr.node_id);
                 for edge_id in begin..end {
@@ -128,6 +132,10 @@ impl PathCalculator {
                 if curr.weight > best_weight {
                     break;
                 }
+                // stall on demand optimization
+                if self.is_stallable_bwd(graph, curr) {
+                    continue;
+                }
                 let begin = graph.begin_in_edges(curr.node_id);
                 let end = graph.end_in_edges(curr.node_id);
                 for edge_id in begin..end {
@@ -158,6 +166,34 @@ impl PathCalculator {
         }
     }
 
+    fn is_stallable_fwd(&self, graph: &FastGraph, curr: HeapItem) -> bool {
+        let begin = graph.begin_in_edges(curr.node_id);
+        let end = graph.end_in_edges(curr.node_id);
+        for edge_id in begin..end {
+            let adj = graph.edges_bwd[edge_id].adj_node;
+            let edge_weight = graph.edges_bwd[edge_id].weight;
+            let adj_weight = self.get_weight_fwd(adj);
+            if adj_weight != WEIGHT_MAX && adj_weight + edge_weight < curr.weight {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    fn is_stallable_bwd(&self, graph: &FastGraph, curr: HeapItem) -> bool {
+        let begin = graph.begin_out_edges(curr.node_id);
+        let end = graph.end_out_edges(curr.node_id);
+        for edge_id in begin..end {
+            let adj = graph.edges_fwd[edge_id].adj_node;
+            let edge_weight = graph.edges_fwd[edge_id].weight;
+            let adj_weight = self.get_weight_bwd(adj);
+            if adj_weight != WEIGHT_MAX && adj_weight + edge_weight < curr.weight {
+                return true;
+            }
+        }
+        return false;
+    }
+
     fn extract_nodes(
         &self,
         graph: &FastGraph,