SharedMemoryMatchingManager.java

/*
 *  Copyright 2015, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 *  WSO2 Inc. licenses this file to you 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.wso2.carbon.registry.event.core.sharedmemory;

import org.wso2.carbon.registry.event.core.delivery.MatchingManager;
import org.wso2.carbon.registry.event.core.sharedmemory.util.SharedMemoryCacheConstants;
import org.wso2.carbon.registry.event.core.subscription.Subscription;
import org.wso2.carbon.registry.event.core.exception.EventBrokerException;
import org.wso2.carbon.context.CarbonContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.cache.Cache;
import javax.cache.CacheConfiguration;
import javax.cache.CacheManager;
import javax.cache.Caching;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * in memory matching manager which keeps the topic and subscriptions in an hash map
 */
public class SharedMemoryMatchingManager implements MatchingManager, Serializable {

    /**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private static final Log log = LogFactory.getLog(SharedMemoryMatchingManager.class);
    private static boolean cacheInit = false;

    private static Cache<Integer, SharedMemorySubscriptionStorage> getTenantIDInMemorySubscriptionStorageCache() {
        if (cacheInit) {
            return Caching.getCacheManagerFactory()
            		.getCacheManager(SharedMemoryCacheConstants.INMEMORY_EVENT_CACHE_MANAGER)
            		.getCache(SharedMemoryCacheConstants.TENANT_ID_INMEMORY_SUBSCRIPTION_STORAGE_CACHE);
        } else {
            CacheManager cacheManager = Caching.getCacheManagerFactory()
            		.getCacheManager(SharedMemoryCacheConstants.INMEMORY_EVENT_CACHE_MANAGER);
            cacheInit = true;
            log.info("Tenant ID InMemory Subscription Storage Cache Initialized");
            return cacheManager.<Integer, SharedMemorySubscriptionStorage>createCacheBuilder(
            		SharedMemoryCacheConstants.TENANT_ID_INMEMORY_SUBSCRIPTION_STORAGE_CACHE).
                    setExpiry(CacheConfiguration.ExpiryType.MODIFIED, new CacheConfiguration.Duration(TimeUnit.SECONDS,
                    		SharedMemoryCacheConstants.CACHE_INVALIDATION_TIME)).
                    setExpiry(CacheConfiguration.ExpiryType.ACCESSED, new CacheConfiguration.Duration(TimeUnit.SECONDS,
                    		SharedMemoryCacheConstants.CACHE_INVALIDATION_TIME)).
                    setStoreByValue(false).build();

        }
    }

    public SharedMemoryMatchingManager() {
    }

    public void addSubscription(Subscription subscription) {
        SharedMemorySubscriptionStorage inMemorySubscriptionStorage =
                getTenantIDInMemorySubscriptionStorageCache()
                        .get(CarbonContext.getThreadLocalCarbonContext().getTenantId());
        inMemorySubscriptionStorage.addSubscription(subscription);
    }

    public List<Subscription> getMatchingSubscriptions(String topicName) {
        SharedMemorySubscriptionStorage inMemorySubscriptionStorage =
                getTenantIDInMemorySubscriptionStorageCache()
                        .get(CarbonContext.getThreadLocalCarbonContext().getTenantId());
        if(inMemorySubscriptionStorage != null) {
            return inMemorySubscriptionStorage.getMatchingSubscriptions(topicName);
        } else {
            return new ArrayList<Subscription>();
        }
    }

    public void unSubscribe(String subscriptionID) throws EventBrokerException {
        SharedMemorySubscriptionStorage inMemorySubscriptionStorage =
                getTenantIDInMemorySubscriptionStorageCache()
                        .get(CarbonContext.getThreadLocalCarbonContext().getTenantId());
        inMemorySubscriptionStorage.unSubscribe(subscriptionID);
    }

    public void renewSubscription(Subscription subscription) throws EventBrokerException {
        SharedMemorySubscriptionStorage inMemorySubscriptionStorage =
                getTenantIDInMemorySubscriptionStorageCache()
                        .get(CarbonContext.getThreadLocalCarbonContext().getTenantId());
        inMemorySubscriptionStorage.renewSubscription(subscription);
    }

    public void initializeTenant() throws EventBrokerException {
        if (getTenantIDInMemorySubscriptionStorageCache()
                .get(CarbonContext.getThreadLocalCarbonContext().getTenantId()) == null){
            getTenantIDInMemorySubscriptionStorageCache().put(
                    CarbonContext.getThreadLocalCarbonContext().getTenantId(), new SharedMemorySubscriptionStorage());
        }
    }
}