com.facebook.buck.rules.BuildRuleResolver.java Source code

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Here is the source code for com.facebook.buck.rules.BuildRuleResolver.java

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/*
 * Copyright 2012-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.rules;

import com.facebook.buck.model.BuildTarget;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.collect.Maps;

import java.util.Map;
import java.util.Set;

import javax.annotation.Nullable;

/**
 * Provides a mechanism for mapping between a {@link BuildTarget} and the {@link BuildRule} it
 * represents. Once parsing is complete, instances of this class can be considered immutable.
 */
public class BuildRuleResolver {

    private final Map<BuildTarget, BuildRule> buildRuleIndex;

    public BuildRuleResolver() {
        this(Maps.<BuildTarget, BuildRule>newConcurrentMap());
    }

    @VisibleForTesting
    public BuildRuleResolver(Map<BuildTarget, BuildRule> buildRuleIndex) {
        Preconditions.checkNotNull(buildRuleIndex);
        this.buildRuleIndex = Maps.newHashMap(buildRuleIndex);
    }

    @VisibleForTesting
    public BuildRuleResolver(Set<? extends BuildRule> startingSet) {
        this.buildRuleIndex = Maps.newConcurrentMap();
        for (BuildRule buildRule : startingSet) {
            this.buildRuleIndex.put(buildRule.getBuildTarget(), buildRule);
        }
    }

    /**
     * @return an unmodifiable view of the rules in the index
     */
    public Iterable<BuildRule> getBuildRules() {
        return Iterables.unmodifiableIterable(buildRuleIndex.values());
    }

    /**
     * Returns the {@link BuildRule} with the {@code fullyQualifiedName}.
     * @param fullyQualifiedName if {@code null}, this method will return {@code null}
     */
    @Nullable
    public BuildRule get(@Nullable BuildTarget fullyQualifiedName) {
        return fullyQualifiedName == null ? null : buildRuleIndex.get(fullyQualifiedName);
    }

    /**
     * Adds to the index a mapping from {@code target} to {@code buildRule}.
     */
    @VisibleForTesting
    public void addToIndex(BuildTarget target, BuildRule buildRule) {
        BuildRule oldValue = buildRuleIndex.put(target, buildRule);
        if (oldValue != null) {
            throw new IllegalStateException("A build rule for this target has already been created: " + target);
        }
    }

    /**
     * Adds to the index a mapping from {@code buildRule}'s target to itself and returns
     * {@code buildRule}.
     */
    @VisibleForTesting
    public <T extends BuildRule> T addToIndex(T buildRule) {
        addToIndex(buildRule.getBuildTarget(), buildRule);
        return buildRule;
    }

    public <T extends BuildRule> T buildAndAddToIndex(BuildRuleBuilder<T> builder) {
        T buildRule = builder.build(this);
        addToIndex(buildRule.getBuildTarget(), buildRule);
        return buildRule;
    }
}