iddb.runtime.cache.impl.CacheImpl.java Source code

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Here is the source code for iddb.runtime.cache.impl.CacheImpl.java

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/**
 *   Copyright(c) 2010-2011 CodWar Soft
 * 
 *   This file is part of IPDB UrT.
 *
 *   IPDB UrT is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This software is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this software. If not, see <http://www.gnu.org/licenses/>.
 */
package iddb.runtime.cache.impl;

import org.apache.commons.lang.StringUtils;

import iddb.core.cache.Cache;
import iddb.core.cache.UnavailableCacheException;

import java.net.InetSocketAddress;
import java.util.Properties;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import net.spy.memcached.MemcachedClient;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class CacheImpl implements Cache {

    private static final Logger log = LoggerFactory.getLogger(CacheImpl.class);

    private MemcachedClient client;
    private Integer expiration = 3600;
    private String namespace;
    private String prefix;
    private String instanceName;

    public CacheImpl() throws UnavailableCacheException {
        Properties props = new Properties();
        try {
            props.load(getClass().getClassLoader().getResourceAsStream("memcache.properties"));
            client = new MemcachedClient(
                    new InetSocketAddress(props.getProperty("host"), Integer.parseInt(props.getProperty("port"))));
            if (props.containsKey("expiration"))
                expiration = Integer.parseInt(props.getProperty("expiration"));
            if (props.containsKey("prefix"))
                prefix = props.getProperty("prefix");
            else
                prefix = "ipdb";
        } catch (Exception e) {
            log.error("Unable to load cache properties [{}]", e.getMessage());
            throw new UnavailableCacheException();
        }
        setNamespace("default");
        log.debug("Initialized memcache instance.");
    }

    private String getCachePrefix() {
        return StringUtils.right(Long.toString(System.currentTimeMillis() / 1000), 5);
    }

    public String getNamespace() {
        return this.instanceName;
    }

    public void setNamespace(String namespace) {
        this.namespace = namespace;
        this.instanceName = this.prefix + "-" + getCachePrefix() + "-" + namespace;
    }

    /* (non-Javadoc)
     * @see iddb.core.cache.Cache#clear()
     */
    @Override
    public void clear() {
        // clear is not supported. lets create a new namespace instead
        setNamespace(this.namespace);
    }

    /* (non-Javadoc)
     * @see iddb.core.cache.Cache#get(java.lang.String)
     */
    @Override
    public Object get(String key) {
        synchronized (key) {
            Object obj = null;
            Future<Object> asGet = client.asyncGet(getNamespace() + "-" + key);
            try {
                obj = asGet.get(10, TimeUnit.SECONDS);
            } catch (TimeoutException e) {
                asGet.cancel(false);
                log.error(e.getMessage());
            } catch (InterruptedException e) {
                log.error(e.getMessage());
            } catch (ExecutionException e) {
                log.error(e.getMessage());
            }
            return obj;
        }
    }

    /* (non-Javadoc)
     * @see iddb.core.cache.Cache#put(java.lang.String, java.lang.Object)
     */
    @Override
    public void put(String key, Object value) {
        if (client == null)
            return;
        client.set(getNamespace() + "-" + key, expiration, value);
    }

    /* (non-Javadoc)
     * @see iddb.core.cache.Cache#put(java.lang.String, java.lang.Object, java.lang.Integer)
     */
    @Override
    public void put(String key, Object value, Integer expire) {
        if (client == null)
            return;
        client.set(getNamespace() + "-" + key, expire, value);
    }

}