| // 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.query2.engine; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Sets; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.Argument; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ArgumentType; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryFunction; |
| import com.google.devtools.build.lib.query2.engine.QueryUtil.ProcessorWithUniquifier; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.concurrent.ForkJoinPool; |
| |
| /** |
| * A "deps" query expression, which computes the dependencies of the argument. An optional |
| * integer-literal second argument may be specified; its value bounds the search from the arguments. |
| * |
| * <pre>expr ::= DEPS '(' expr ')'</pre> |
| * <pre> | DEPS '(' expr ',' WORD ')'</pre> |
| */ |
| final class DepsFunction implements QueryFunction { |
| DepsFunction() { |
| } |
| |
| @Override |
| public String getName() { |
| return "deps"; |
| } |
| |
| @Override |
| public int getMandatoryArguments() { |
| return 1; // last argument is optional |
| } |
| |
| @Override |
| public List<ArgumentType> getArgumentTypes() { |
| return ImmutableList.of(ArgumentType.EXPRESSION, ArgumentType.INTEGER); |
| } |
| |
| private static class ProcessorImpl<T> implements ProcessorWithUniquifier<T> { |
| private final QueryExpression expression; |
| private final int depthBound; |
| private final QueryEnvironment<T> env; |
| |
| private ProcessorImpl(QueryExpression expression, int depthBound, QueryEnvironment<T> env) { |
| this.expression = expression; |
| this.depthBound = depthBound; |
| this.env = env; |
| } |
| |
| @Override |
| public void process(Iterable<T> partialResult, Uniquifier<T> uniquifier, Callback<T> callback) |
| throws QueryException, InterruptedException { |
| Collection<T> current = Sets.newHashSet(partialResult); |
| env.buildTransitiveClosure(expression, (Set<T>) current, depthBound); |
| |
| // We need to iterate depthBound + 1 times. |
| for (int i = 0; i <= depthBound; i++) { |
| // Filter already visited nodes: if we see a node in a later round, then we don't need to |
| // visit it again, because the depth at which we see it at must be greater than or equal |
| // to the last visit. |
| ImmutableList<T> toProcess = uniquifier.unique(current); |
| callback.process(toProcess); |
| current = ImmutableList.copyOf(env.getFwdDeps(toProcess)); |
| if (current.isEmpty()) { |
| // Exit when there are no more nodes to visit. |
| break; |
| } |
| } |
| } |
| } |
| |
| private static <T> void doEval( |
| QueryEnvironment<T> env, |
| VariableContext<T> context, |
| QueryExpression expression, |
| List<Argument> args, |
| Callback<T> callback) throws QueryException, InterruptedException { |
| int depthBound = args.size() > 1 ? args.get(1).getInteger() : Integer.MAX_VALUE; |
| env.eval( |
| args.get(0).getExpression(), |
| context, |
| QueryUtil.compose( |
| new ProcessorImpl<T>(expression, depthBound, env), |
| env.createUniquifier(), |
| callback)); |
| } |
| |
| /** |
| * Breadth-first search from the arguments. |
| */ |
| @Override |
| public <T> void eval( |
| QueryEnvironment<T> env, |
| VariableContext<T> context, |
| QueryExpression expression, |
| List<Argument> args, |
| Callback<T> callback) throws QueryException, InterruptedException { |
| doEval(env, context, expression, args, callback); |
| } |
| |
| @Override |
| public <T> void parEval( |
| QueryEnvironment<T> env, |
| VariableContext<T> context, |
| QueryExpression expression, |
| List<Argument> args, |
| ThreadSafeCallback<T> callback, |
| ForkJoinPool forkJoinPool) throws QueryException, InterruptedException { |
| doEval(env, context, expression, args, callback); |
| } |
| } |