Add EntityMap::extend and deprecate VertexMap/EdgeMap::sync

src/maps.rs

@@ -23,8 +23,18 @@ impl<V: Copy, T: Clone> VertexMap<V, T> {
         self.capacity()
     }
 
+    /// Extends the internal data storage of the map to `capacity`, pre-filling any new slots with
+    /// the default value.
+    ///
+    /// Use this before writing data for new graph vertices to avoid incremental growth on the first
+    /// write to each new vertex.
+    pub fn extend(&mut self, capacity: usize) {
+        self.inner.extend(capacity);
+    }
+
+    #[deprecated(since = "0.2.4", note = "use 'extend(graph.vertex_capacity())' instead")]
     pub fn sync<G: GraphTopology<Vertex = V>>(&mut self, graph: &G) {
-        self.inner.resize(graph.vertex_capacity());
+        self.inner.extend(graph.vertex_capacity());
     }
 }
 
@@ -63,8 +73,18 @@ impl<E: Copy, T: Clone> EdgeMap<E, T> {
         self.capacity()
     }
 
+    /// Extends the internal data storage of the map to `capacity`, pre-filling any new slots with
+    /// the default value.
+    ///
+    /// Use this before writing data for new graph edges to avoid incremental growth on the first
+    /// write to each new edge.
+    pub fn extend(&mut self, capacity: usize) {
+        self.inner.extend(capacity);
+    }
+
+    #[deprecated(since = "0.2.4", note = "use 'extend(graph.edge_capacity())' instead")]
     pub fn sync<G: GraphTopology<Edge = E>>(&mut self, graph: &G) {
-        self.inner.resize(graph.edge_capacity());
+        self.inner.extend(graph.edge_capacity());
     }
 }
 
@@ -101,8 +121,8 @@ impl<E: Copy, T: Clone> EntityMap<E, T> {
         self.data.len()
     }
 
-    pub fn resize(&mut self, capacity: usize) {
+    pub fn extend(&mut self, capacity: usize) {
-        if capacity > self.data.len() {
+        if capacity > self.data.capacity() {
             self.data.resize(capacity, self.default.clone());
         }
     }