// Copyright 2014 The Bazel Authors. All rights reserved. // // 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.google.devtools.build.lib.actions; /** * An abstract visitor for the action graph. Specializes {@link BipartiteVisitor} for artifacts and * actions, and takes care of visiting the complete transitive closure. */ public abstract class ActionGraphVisitor extends BipartiteVisitor<ActionAnalysisMetadata, Artifact> { private final ActionGraph actionGraph; public ActionGraphVisitor(ActionGraph actionGraph) { this.actionGraph = actionGraph; } /** * Called for all artifacts in the visitation. Hook for subclasses. * * @param artifact */ protected void visitArtifact(Artifact artifact) {} /** * Called for all actions in the visitation. Hook for subclasses. * * @param action */ protected void visitAction(ActionAnalysisMetadata action) {} /** * Whether the given action should be visited. If this returns false, the visitation stops here, * so the dependencies of this action are also not visited. * * @param action */ protected boolean shouldVisit(ActionAnalysisMetadata action) { return true; } /** * Whether the given artifact should be visited. If this returns false, the visitation stops here, * so dependencies of this artifact (if it is a generated one) are also not visited. * * @param artifact */ protected boolean shouldVisit(Artifact artifact) { return true; } @SuppressWarnings("unused") protected final void visitArtifacts(Iterable<Artifact> artifacts) { for (Artifact artifact : artifacts) { visitArtifact(artifact); } } @Override protected void white(Artifact artifact) { ActionAnalysisMetadata action = actionGraph.getGeneratingAction(artifact); visitArtifact(artifact); if (action != null && shouldVisit(action)) { visitBlackNode(action); } } @Override protected void black(ActionAnalysisMetadata action) { visitAction(action); for (Artifact input : action.getInputs()) { if (shouldVisit(input)) { visitWhiteNode(input); } } } }