com.google.devtools.build.lib.query2.RBuildFilesFunction.java Source code

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Here is the source code for com.google.devtools.build.lib.query2.RBuildFilesFunction.java

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// 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;

import com.google.common.base.Function;
import com.google.common.collect.Collections2;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.query2.engine.Callback;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment;
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.QueryException;
import com.google.devtools.build.lib.query2.engine.QueryExpression;
import com.google.devtools.build.lib.query2.engine.ThreadSafeCallback;
import com.google.devtools.build.lib.query2.engine.VariableContext;
import com.google.devtools.build.lib.vfs.PathFragment;

import java.util.List;
import java.util.concurrent.ForkJoinPool;

/**
 * An "rbuildfiles" query expression, which computes the set of packages (as represented by their
 * BUILD source file targets) that depend on the given set of files, either as BUILD files directly
 * or as subincludes. Is morally the inverse of the "buildfiles" operator, although that operator
 * takes targets and returns subinclude targets, while this takes files and returns BUILD file
 * targets.
 *
 * <pre>expr ::= RBUILDFILES '(' WORD, ... ')'</pre>
 *
 * <p>This expression can only be used with SkyQueryEnvironment.
 */
public class RBuildFilesFunction implements QueryFunction {

    @Override
    public String getName() {
        return "rbuildfiles";
    }

    @Override
    public int getMandatoryArguments() {
        return 1;
    }

    @Override
    public Iterable<ArgumentType> getArgumentTypes() {
        return Iterables.cycle(ArgumentType.WORD);
    }

    private static final Function<Argument, PathFragment> ARGUMENT_TO_PATH_FRAGMENT = new Function<Argument, PathFragment>() {
        @Override
        public PathFragment apply(Argument argument) {
            return new PathFragment(argument.getWord());
        }
    };

    @Override
    @SuppressWarnings("unchecked") // Cast from <Target> to <T>. This will only be used with <Target>.
    public <T> void eval(QueryEnvironment<T> env, VariableContext<T> context, QueryExpression expression,
            List<Argument> args, Callback<T> callback) throws QueryException, InterruptedException {
        if (!(env instanceof SkyQueryEnvironment)) {
            throw new QueryException("rbuildfiles can only be used with SkyQueryEnvironment");
        }
        ((SkyQueryEnvironment) env).getRBuildFiles(Collections2.transform(args, ARGUMENT_TO_PATH_FRAGMENT),
                (Callback<Target>) callback);
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> void parEval(QueryEnvironment<T> env, VariableContext<T> context, QueryExpression expression,
            List<Argument> args, ThreadSafeCallback<T> callback, ForkJoinPool forkJoinPool)
            throws QueryException, InterruptedException {
        if (!(env instanceof SkyQueryEnvironment)) {
            throw new QueryException("rbuildfiles can only be used with SkyQueryEnvironment");
        }
        ((SkyQueryEnvironment) env).getRBuildFilesParallel(Collections2.transform(args, ARGUMENT_TO_PATH_FRAGMENT),
                (ThreadSafeCallback<Target>) callback, forkJoinPool);
    }
}