| /* |
| * Copyright 2012-present Facebook, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. You may obtain |
| * a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| package com.facebook.buck.graph; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.collect.ImmutableSetMultimap; |
| import com.google.common.collect.Sets; |
| |
| import java.util.Objects; |
| |
| public class DefaultDirectedAcyclicGraph<T> implements DirectedAcyclicGraph<T> { |
| |
| private final ImmutableSet<T> nodes; |
| private final ImmutableSetMultimap<T, T> outgoingEdges; |
| private final ImmutableSetMultimap<T, T> incomingEdges; |
| |
| public DefaultDirectedAcyclicGraph(MutableDirectedGraph<T> graph) { |
| Preconditions.checkArgument(graph.isAcyclic()); |
| this.nodes = graph.createImmutableCopyOfNodes(); |
| this.outgoingEdges = graph.createImmutableCopyOfOutgoingEdges(); |
| this.incomingEdges = graph.createImmutableCopyOfIncomingEdges(); |
| } |
| |
| @Override |
| public ImmutableSet<T> getOutgoingNodesFor(T source) { |
| return outgoingEdges.get(source); |
| } |
| |
| @Override |
| public ImmutableSet<T> getIncomingNodesFor(T sink) { |
| return incomingEdges.get(sink); |
| } |
| |
| @Override |
| public ImmutableSet<T> getNodesWithNoOutgoingEdges() { |
| return ImmutableSet.copyOf(Sets.difference(nodes, outgoingEdges.keySet())); |
| } |
| |
| @Override |
| public ImmutableSet<T> getNodesWithNoIncomingEdges() { |
| return ImmutableSet.copyOf(Sets.difference(nodes, incomingEdges.keySet())); |
| } |
| |
| /** @return an unmodifiable view of the nodes in this graph */ |
| public ImmutableSet<T> getNodes() { |
| return nodes; |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| if (!(other instanceof DefaultDirectedAcyclicGraph)) { |
| return false; |
| } |
| |
| DefaultDirectedAcyclicGraph<?> that = (DefaultDirectedAcyclicGraph<?>) other; |
| return Objects.equals(this.nodes, that.nodes) && |
| Objects.equals(this.outgoingEdges, that.outgoingEdges) && |
| Objects.equals(this.incomingEdges, that.incomingEdges); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(nodes, outgoingEdges, incomingEdges); |
| } |
| } |