com.google.dart.engine.internal.index.file.CachingNodeManager.java Source code

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Here is the source code for com.google.dart.engine.internal.index.file.CachingNodeManager.java

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/*
 * Copyright (c) 2014, the Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 * 
 * 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.dart.engine.internal.index.file;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.util.concurrent.Uninterruptibles;
import com.google.dart.engine.context.AnalysisContext;

import java.util.concurrent.TimeUnit;

/**
 * A {@link NodeManager} that caches {@link IndexNode} accessed from another {@link NodeManager}.
 * <p>
 * By default up to 64 nodes are cached for 5 seconds.
 * 
 * @coverage dart.engine.index
 */
public class CachingNodeManager implements NodeManager {
    /**
     * A {@link Thread} that performs {@link #cache} clean up.
     */
    private class CleanUpThread extends Thread {
        public CleanUpThread() {
            super("IndexNode cache clean up thread");
            setDaemon(true);
        }

        @Override
        public void run() {
            while (true) {
                cache.cleanUp();
                Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
            }
        }
    }

    private final NodeManager manager;
    private final Cache<String, IndexNode> cache;

    public CachingNodeManager(NodeManager manager) {
        this.manager = manager;
        {
            CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder();
            cache = builder.maximumSize(64).expireAfterAccess(5, TimeUnit.SECONDS).build();
        }
        new CleanUpThread().start();
    }

    @Override
    public void clear() {
        manager.clear();
        cache.invalidateAll();
    }

    @Override
    public ContextCodec getContextCodec() {
        return manager.getContextCodec();
    }

    @Override
    public ElementCodec getElementCodec() {
        return manager.getElementCodec();
    }

    @Override
    public int getLocationCount() {
        return manager.getLocationCount();
    }

    @Override
    public IndexNode getNode(String name) {
        IndexNode node = cache.getIfPresent(name);
        if (node == null) {
            node = manager.getNode(name);
            if (node != null) {
                cache.put(name, node);
            }
        }
        return node;
    }

    @Override
    public StringCodec getStringCodec() {
        return manager.getStringCodec();
    }

    @Override
    public IndexNode newNode(AnalysisContext context) {
        return manager.newNode(context);
    }

    @Override
    public void putNode(String name, IndexNode node) {
        cache.put(name, node);
        manager.putNode(name, node);
    }

    @Override
    public void removeNode(String name) {
        cache.invalidate(name);
        manager.removeNode(name);
    }
}