org.semispace.google.space.address.GoogleAddressFetcher.java Source code

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Here is the source code for org.semispace.google.space.address.GoogleAddressFetcher.java

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/*
 * ============================================================================
 *
 *  File:     GoogleAddressFetcher.java
 *----------------------------------------------------------------------------
 *
 * Copyright 2008 Erlend Nossum
 *
 * 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.
 *
 *  Description:  See javadoc below
 *
 *  Created:      Oct 4, 2008
 * ============================================================================ 
 */

package org.semispace.google.space.address;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.semispace.SemiEventListener;
import org.semispace.SemiEventRegistration;
import org.semispace.SemiSpace;
import org.semispace.SemiSpaceInterface;
import org.semispace.event.SemiAvailabilityEvent;
import org.semispace.event.SemiEvent;
import org.semispace.google.transport.AddressQuery;
import org.springframework.beans.factory.DisposableBean;

public class GoogleAddressFetcher implements DisposableBean, SemiEventListener {
    private static final Logger log = LoggerFactory.getLogger(GoogleAddressFetcher.class);

    protected static final long TEN_YEARS = SemiSpace.ONE_DAY * 365 * 10;

    private SemiEventRegistration lease = null;

    private SemiSpaceInterface space;
    private int simultanousLookups;

    private ExecutorService threadPool;

    public int getSimultanousLookups() {
        return this.simultanousLookups;
    }

    public void setSimultanousLookups(int simultanousLookups) {
        this.simultanousLookups = simultanousLookups;
    }

    public void setSpace(SemiSpaceInterface space) {
        this.space = space;
    }

    public void init() {
        log.debug("Initializing " + getClass().getName());
        threadPool = Executors.newCachedThreadPool();

        // TODO Que?
        //AddressLookupSemaphore counter = new AddressLookupSemaphore();
        if (simultanousLookups < 1) {
            throw new RuntimeException(
                    "Configuration error - need to configure field simultanousLookups to a value greater than 0.");
        }
        resetSemaphores();
        // Add notifier for query
        if (lease != null) {
            log.warn("Double initialization? Strange.");
            lease.getLease().cancel();
        }
        lease = space.notify(new AddressQuery(), this, TEN_YEARS);
    }

    private void resetSemaphores() {
        while (space.takeIfExists(new AddressLookupSemaphore()) != null) {
            // Intentional
        }
        for (int i = 0; i < simultanousLookups; i++) {
            space.write(new AddressLookupSemaphore(), TEN_YEARS);
        }
    }

    public void destroy() throws Exception {
        if (lease != null) {
            lease.getLease().cancel();
        }
    }

    public void notify(SemiEvent theEvent) {
        if (theEvent instanceof SemiAvailabilityEvent) {
            if (space.readIfExists(new AddressQuery()) == null) {
                log.warn("Could not read element even when getting availability in " + this + " Incoming event: "
                        + theEvent.getClass().getName() + " #" + theEvent.getId());
            } else {
                log.info("Object read OK in " + this);
            }
            spawnThreadToTakeCareOfQuery();
        }
    }

    private void spawnThreadToTakeCareOfQuery() {
        threadPool.execute(new FetchAddress(space));
    }
}