| // Copyright 2015 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.base.Predicate; |
| import com.google.common.base.Predicates; |
| 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 java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * An "allrdeps" query expression, which computes the reverse dependencies of the argument within |
| * the currently known universe. An optional integer-literal second argument may be specified; its |
| * value bounds the search from the arguments. |
| * |
| * <pre>expr ::= ALLRDEPS '(' expr ')'</pre> |
| * <pre> | ALLRDEPS '(' expr ',' WORD ')'</pre> |
| */ |
| // Public because SkyQueryEnvironment needs to refer to it directly. |
| public class AllRdepsFunction implements QueryFunction { |
| |
| @Override |
| public String getName() { |
| return "allrdeps"; |
| } |
| |
| @Override |
| public int getMandatoryArguments() { |
| return 1; // last argument is optional |
| } |
| |
| @Override |
| public List<ArgumentType> getArgumentTypes() { |
| return ImmutableList.of(ArgumentType.EXPRESSION, ArgumentType.INTEGER); |
| } |
| |
| @Override |
| public <T> QueryTaskFuture<Void> eval( |
| QueryEnvironment<T> env, |
| QueryExpressionContext<T> context, |
| QueryExpression expression, |
| List<Argument> args, |
| Callback<T> callback) { |
| boolean isDepthUnbounded = args.size() == 1; |
| int depth = isDepthUnbounded ? Integer.MAX_VALUE : args.get(1).getInteger(); |
| QueryExpression argumentExpression = args.get(0).getExpression(); |
| if (env instanceof StreamableQueryEnvironment) { |
| StreamableQueryEnvironment<T> streamableEnv = (StreamableQueryEnvironment<T>) env; |
| return isDepthUnbounded |
| ? streamableEnv.getAllRdepsUnboundedParallel(argumentExpression, context, callback) |
| : streamableEnv.getAllRdepsBoundedParallel(argumentExpression, depth, context, callback); |
| } else { |
| return eval( |
| env, |
| argumentExpression, |
| Predicates.<T>alwaysTrue(), |
| context, |
| callback, |
| depth); |
| } |
| } |
| |
| /** Common non-parallel implementation of depth-bounded allrdeps/deps. */ |
| static <T> QueryTaskFuture<Void> eval( |
| final QueryEnvironment<T> env, |
| QueryExpression expression, |
| final Predicate<T> universe, |
| QueryExpressionContext<T> context, |
| final Callback<T> callback, |
| final int depth) { |
| final MinDepthUniquifier<T> minDepthUniquifier = env.createMinDepthUniquifier(); |
| return env.eval( |
| expression, |
| context, |
| new Callback<T>() { |
| @Override |
| public void process(Iterable<T> partialResult) |
| throws QueryException, InterruptedException { |
| Iterable<T> current = partialResult; |
| // We need to iterate depthBound + 1 times. |
| for (int i = 0; i <= depth; i++) { |
| List<T> next = new ArrayList<>(); |
| // Restrict to nodes satisfying the universe predicate. |
| Iterable<T> currentInUniverse = Iterables.filter(current, universe); |
| // 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 must be greater |
| // than or equal to the last visit. |
| Iterables.addAll( |
| next, |
| env.getReverseDeps( |
| minDepthUniquifier.uniqueAtDepthLessThanOrEqualTo(currentInUniverse, i), |
| context)); |
| callback.process(currentInUniverse); |
| if (next.isEmpty()) { |
| // Exit when there are no more nodes to visit. |
| break; |
| } |
| current = next; |
| } |
| } |
| }); |
| } |
| } |