com.cognifide.aet.rest.LockService.java Source code

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Here is the source code for com.cognifide.aet.rest.LockService.java

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/**
 * Automated Exploratory Tests
 *
 * Copyright (C) 2013 Cognifide Limited
 *
 * 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 com.cognifide.aet.rest;

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

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.ConfigurationPolicy;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Service;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;
import java.util.Map;
import java.util.concurrent.TimeUnit;

@Service(LockService.class)
@Component(label = "LockService", description = "Provides lock service", immediate = true, metatype = true, policy = ConfigurationPolicy.IGNORE)
public class LockService implements Serializable {

    private static final long serialVersionUID = 101244102266582495L;

    private static final Logger LOGGER = LoggerFactory.getLogger(LockService.class);

    private static final int LOCK_CACHE_TIMEOUT = 20000;

    private transient Cache<String, String> lockSet;

    @Activate
    public void start() {
        LOGGER.debug("Starting lock service");
        lockSet = CacheBuilder.newBuilder().expireAfterWrite(LOCK_CACHE_TIMEOUT, TimeUnit.MILLISECONDS).build();
    }

    @Deactivate
    public void stop() {
        LOGGER.debug("Stopping lock service");
    }

    public void setLock(String key, String value) {
        lockSet.put(key, value);
    }

    public boolean isLockPresent(String key) {
        return null != lockSet.getIfPresent(key);
    }

    public synchronized boolean trySetLock(String key, String value) {
        if (null == lockSet.getIfPresent(key)) {
            lockSet.put(key, value);
            return true;
        }
        return false;
    }

    public Map<String, String> getAllLocks() {
        return ImmutableMap.copyOf(lockSet.asMap());
    }

}