| // 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.base.Predicate; |
| import com.google.common.base.Predicates; |
| import com.google.common.collect.ImmutableList; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.Argument; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ArgumentType; |
| |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * An "rdeps" query expression, which computes the reverse dependencies of the argument within the |
| * transitive closure of the universe. An optional integer-literal third argument may be |
| * specified; its value bounds the search from the arguments. |
| * |
| * <pre>expr ::= RDEPS '(' expr ',' expr ')'</pre> |
| * <pre> | RDEPS '(' expr ',' expr ',' WORD ')'</pre> |
| */ |
| public final class RdepsFunction extends AllRdepsFunction { |
| public RdepsFunction() {} |
| |
| @Override |
| public String getName() { |
| return "rdeps"; |
| } |
| |
| @Override |
| public int getMandatoryArguments() { |
| return super.getMandatoryArguments() + 1; // +1 for the universe. |
| } |
| |
| @Override |
| public List<ArgumentType> getArgumentTypes() { |
| return ImmutableList.<ArgumentType>builder() |
| .add(ArgumentType.EXPRESSION).addAll(super.getArgumentTypes()).build(); |
| } |
| |
| /** |
| * Compute the transitive closure of the universe, then breadth-first search from the argument |
| * towards the universe while staying within the transitive closure. |
| */ |
| @Override |
| public <T> void eval(QueryEnvironment<T> env, |
| VariableContext<T> context, |
| QueryExpression expression, |
| List<Argument> args, Callback<T> callback) |
| throws QueryException, |
| InterruptedException { |
| Set<T> universeValue = QueryUtil.evalAll(env, context, args.get(0).getExpression()); |
| env.buildTransitiveClosure(expression, universeValue, Integer.MAX_VALUE); |
| |
| Predicate<T> universe = Predicates.in(env.getTransitiveClosure(universeValue)); |
| eval(env, context, args.subList(1, args.size()), callback, universe); |
| } |
| } |