Java tutorial
/* * 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.rules; import com.facebook.buck.graph.DefaultImmutableDirectedAcyclicGraph; import com.facebook.buck.graph.MutableDirectedGraph; import com.facebook.buck.model.BuildTarget; import com.google.common.collect.ImmutableMap; import java.util.Map; public class DependencyGraph extends DefaultImmutableDirectedAcyclicGraph<BuildRule> { private Map<BuildTarget, BuildRule> index; public DependencyGraph(MutableDirectedGraph<BuildRule> graph) { super(graph); } public BuildRule findBuildRuleByTarget(BuildTarget buildTarget) { if (index == null) { ImmutableMap.Builder<BuildTarget, BuildRule> builder = ImmutableMap.builder(); for (BuildRule rule : getNodes()) { builder.put(rule.getBuildTarget(), rule); } index = builder.build(); } return index.get(buildTarget); } }