hudson.model.TopLevelItemsCache Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2013 Hudson.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Hudson - initial API and implementation and/or initial documentation
 */
package hudson.model;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * A cache for {@link TopLevelItems} object that are directly held by
 * the {@link Hudson} instance.
 * 
 * This class is package private.
 * 
 * @author Roy Varghese
 */
class TopLevelItemsCache {
    
    // Cache parameters
    private final static int EVICT_IN_SECONDS = 60;
    private final static int INITIAL_CAPACITY = 1024;
    private final static int MAX_ENTRIES = 1000;
    
    final LoadingCache cache;
    
    TopLevelItemsCache() { 
        
        cache = CacheBuilder.newBuilder()
                .initialCapacity(INITIAL_CAPACITY)
                .expireAfterAccess(EVICT_IN_SECONDS, TimeUnit.SECONDS)
                .maximumSize(MAX_ENTRIES)
                .softValues()
                .removalListener(new RemovalListener() {

                    @Override
                    public void onRemoval(RemovalNotification notification) {
                        // System.out.println("*** Removed from cache " + notification.getKey().name );
                    }
                    
                })
                .build(new CacheLoader() {
                    
                    Map map = new HashMap();

                    @Override
                    public TopLevelItem load(LazyTopLevelItem.Key key) throws Exception {
                        TopLevelItem item = (TopLevelItem) key.configFile.read();
                        item.onLoad(key.parent, key.name);
                        return item;
                    }
                    
                });
        
        

    }
    
    
    
    TopLevelItem get(LazyTopLevelItem.Key key) {
        try {
            return cache.get(key);
        } catch (ExecutionException ex) {
            Logger.getLogger(TopLevelItemsCache.class.getName()).log(Level.SEVERE, null, ex);
            return null;
        }

    }
    
    void put(LazyTopLevelItem.Key key, TopLevelItem item) {
        cache.put(key, item);
    }
    
}