com.google.devtools.build.skyframe.RecordingDifferencer.java Source code

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Here is the source code for com.google.devtools.build.skyframe.RecordingDifferencer.java

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// 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.skyframe;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.concurrent.ThreadSafety;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * A simple Differencer which just records the invalidated values it's been given.
 */
@ThreadSafety.ThreadCompatible
public class RecordingDifferencer implements Differencer, Injectable {

    private List<SkyKey> valuesToInvalidate;
    private Map<SkyKey, SkyValue> valuesToInject;

    public RecordingDifferencer() {
        clear();
    }

    private void clear() {
        valuesToInvalidate = new ArrayList<>();
        valuesToInject = new HashMap<>();
    }

    @Override
    public Diff getDiff(WalkableGraph fromGraph, Version fromVersion, Version toVersion) {
        Diff diff = new ImmutableDiff(valuesToInvalidate, valuesToInject);
        clear();
        return diff;
    }

    /**
     * Store the given values for invalidation.
     */
    public void invalidate(Iterable<SkyKey> values) {
        Iterables.addAll(valuesToInvalidate, values);
    }

    /**
     * Invalidates the cached values of any values in error transiently.
     *
     * <p>If a future call to {@link MemoizingEvaluator#evaluate} requests a value that transitively
     * depends on any value that was in an error state (or is one of these), they will be re-computed.
     */
    public void invalidateTransientErrors() {
        // All transient error values have a dependency on the single global ERROR_TRANSIENCE value,
        // so we only have to invalidate that one value to catch everything.
        invalidate(ImmutableList.of(ErrorTransienceValue.KEY));
    }

    /**
     * Store the given values for injection.
     */
    @Override
    public void inject(Map<SkyKey, ? extends SkyValue> values) {
        valuesToInject.putAll(values);
    }

    @Override
    public void inject(SkyKey key, SkyValue value) {
        valuesToInject.put(key, value);
    }
}