| // 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.Iterables; |
| 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.QueryEnvironment.QueryTaskFuture; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ThreadSafeMutableSet; |
| import java.util.List; |
| |
| /** |
| * 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); |
| } |
| |
| /** Breadth-first search from the arguments. */ |
| @Override |
| public <T> QueryTaskFuture<Void> eval( |
| final QueryEnvironment<T> env, |
| QueryExpressionContext<T> context, |
| final QueryExpression expression, |
| List<Argument> args, |
| final Callback<T> callback) { |
| QueryExpression queryExpression = args.get(0).getExpression(); |
| if (env instanceof StreamableQueryEnvironment && args.size() == 1) { |
| StreamableQueryEnvironment<T> streamableEnv = (StreamableQueryEnvironment<T>) env; |
| return streamableEnv.getDepsUnboundedParallel( |
| queryExpression, |
| context, |
| /*callback=*/ partialResult -> { |
| callback.process(partialResult); |
| ThreadSafeMutableSet<T> set = env.createThreadSafeMutableSet(); |
| Iterables.addAll(set, partialResult); |
| // Ensure the proper error messages are reported. |
| env.buildTransitiveClosure(expression, set, /*maxDepth=*/ 1); |
| }); |
| } |
| |
| final int depthBound = args.size() > 1 ? args.get(1).getInteger() : Integer.MAX_VALUE; |
| final MinDepthUniquifier<T> minDepthUniquifier = env.createMinDepthUniquifier(); |
| return env.eval( |
| queryExpression, |
| context, |
| partialResult -> { |
| ThreadSafeMutableSet<T> current = env.createThreadSafeMutableSet(); |
| Iterables.addAll(current, partialResult); |
| env.buildTransitiveClosure(expression, 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 = |
| minDepthUniquifier.uniqueAtDepthLessThanOrEqualTo(current, i); |
| callback.process(toProcess); |
| current = env.createThreadSafeMutableSet(); |
| Iterables.addAll(current, env.getFwdDeps(toProcess, context)); |
| if (current.isEmpty()) { |
| // Exit when there are no more nodes to visit. |
| break; |
| } |
| } |
| }); |
| } |
| } |