org.onebusaway.presentation.services.cachecontrol.SiriCacheServiceImpl.java Source code

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Here is the source code for org.onebusaway.presentation.services.cachecontrol.SiriCacheServiceImpl.java

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/**
 * Copyright (C) 2010 OpenPlans
 *
 * 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 org.onebusaway.presentation.services.cachecontrol;

import java.util.List;
import java.util.Map.Entry;
import java.util.TreeSet;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;

import org.onebusaway.container.refresh.Refreshable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

@Component("CacheService")
public class SiriCacheServiceImpl extends CacheService<Integer, String> {

    private static final int DEFAULT_CACHE_TIMEOUT = 30;
    private static final String SIRI_CACHE_TIMEOUT_KEY = "cache.expiry.siri";

    public synchronized Cache<Integer, String> getCache() {
        return getCache(DEFAULT_CACHE_TIMEOUT, "SIRI");
    }

    @Override
    @Refreshable(dependsOn = { SIRI_CACHE_TIMEOUT_KEY })
    protected synchronized void refreshCache() {
        if (_cache == null)
            return;
        int timeout = DEFAULT_CACHE_TIMEOUT;
        _log.info("rebuilding siri cache with " + _cache.size() + " entries after refresh with timeout=" + timeout
                + "...");
        ConcurrentMap<Integer, String> map = _cache.asMap();
        _cache = CacheBuilder.newBuilder().expireAfterWrite(timeout, TimeUnit.SECONDS).build();
        for (Entry<Integer, String> entry : map.entrySet()) {
            _cache.put(entry.getKey(), entry.getValue());
        }
        _log.info("done");
    }

    private Integer hash(int maximumOnwardCalls, List<String> agencies, String outputType) {
        // Use properties of a TreeSet to obtain consistent ordering of like combinations of agencies
        TreeSet<String> set = new TreeSet<String>(agencies);
        return maximumOnwardCalls + set.toString().hashCode() + outputType.hashCode();
    }

    @SuppressWarnings("unchecked")
    @Override
    public Integer hash(Object... factors) {
        return hash((Integer) factors[0], (List<String>) factors[1], (String) factors[2]);
    }

    public void store(Integer key, String value) {
        int timeout = DEFAULT_CACHE_TIMEOUT;
        super.store(key, value, timeout);
    }

}