com.facebook.buck.query.AttrFilterFunction.java Source code

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Here is the source code for com.facebook.buck.query.AttrFilterFunction.java

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/*
 * Copyright 2015-present Facebook, Inc.
 *
 * 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.facebook.buck.query;

import com.facebook.buck.query.QueryEnvironment.Argument;
import com.facebook.buck.query.QueryEnvironment.ArgumentType;
import com.facebook.buck.query.QueryEnvironment.QueryFunction;
import com.google.common.base.CaseFormat;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.util.concurrent.ListeningExecutorService;

import java.util.LinkedHashSet;
import java.util.Set;

/**
 * A attrfilter(attribute, value, argument) filter expression, which computes the subset
 * of nodes in 'argument' whose 'attribute' contains the given value.
 *
 * <pre>expr ::= ATTRFILTER '(' WORD ',' WORD ',' expr ')'</pre>
 */
public class AttrFilterFunction implements QueryFunction {

    private static final ImmutableList<ArgumentType> ARGUMENT_TYPES = ImmutableList.of(ArgumentType.WORD,
            ArgumentType.WORD, ArgumentType.EXPRESSION);

    public AttrFilterFunction() {
    }

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

    @Override
    public int getMandatoryArguments() {
        return 3;
    }

    @Override
    public ImmutableList<ArgumentType> getArgumentTypes() {
        return ARGUMENT_TYPES;
    }

    @Override
    public Set<QueryTarget> eval(QueryEnvironment env, ImmutableList<Argument> args,
            ListeningExecutorService executor) throws QueryException, InterruptedException {
        QueryExpression argument = args.get(args.size() - 1).getExpression();
        String attr = CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, args.get(0).getWord());

        final String attrValue = args.get(1).getWord();
        final Predicate<Object> predicate = input -> attrValue.equals(input.toString());

        Set<QueryTarget> result = new LinkedHashSet<>();
        for (QueryTarget target : argument.eval(env, executor)) {
            ImmutableSet<Object> matchingObjects = env.filterAttributeContents(target, attr, predicate);
            if (!matchingObjects.isEmpty()) {
                result.add(target);
            }
        }
        return result;
    }

}