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Diffstat (limited to 'java/broker/src/main/java/org/apache/qpid/server/queue/SubscriptionSet.java')
| -rw-r--r-- | java/broker/src/main/java/org/apache/qpid/server/queue/SubscriptionSet.java | 278 |
1 files changed, 0 insertions, 278 deletions
diff --git a/java/broker/src/main/java/org/apache/qpid/server/queue/SubscriptionSet.java b/java/broker/src/main/java/org/apache/qpid/server/queue/SubscriptionSet.java deleted file mode 100644 index 117799ad87..0000000000 --- a/java/broker/src/main/java/org/apache/qpid/server/queue/SubscriptionSet.java +++ /dev/null @@ -1,278 +0,0 @@ -/* - * - * Licensed to the Apache Software Foundation (ASF) under one - * or more contributor license agreements. See the NOTICE file - * distributed with this work for additional information - * regarding copyright ownership. The ASF 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.apache.qpid.server.queue; - -import java.util.List; -import java.util.ListIterator; -import java.util.Map; -import java.util.concurrent.CopyOnWriteArrayList; -import java.util.concurrent.ConcurrentHashMap; - -import org.apache.log4j.Logger; -import org.apache.qpid.server.subscription.Subscription; - -/** Holds a set of subscriptions for a queue and manages the round robin-ing of deliver etc. */ -class SubscriptionSet implements SubscriptionManager -{ - private static final Logger _log = Logger.getLogger(SubscriptionSet.class); - - /** List of registered subscribers */ - private final List<Subscription> _subscriptions = new CopyOnWriteArrayList<Subscription>(); - - private final Map<Subscription, DeliveryAgent> _deliveryAgents = - new ConcurrentHashMap<Subscription, DeliveryAgent>(); - - - /** Used to control the round robin delivery of content */ - private int _currentSubscriber; - private final Object _changeLock = new Object(); - private volatile boolean _exclusive; - - - /** Accessor for unit tests. */ - int getCurrentSubscriber() - { - return _currentSubscriber; - } - - public void addSubscriber(Subscription subscription) - { - synchronized (_changeLock) - { - _subscriptions.add(subscription); - _deliveryAgents.put(subscription, new DeliveryAgent(subscription)); - } - } - - /** - * Remove the subscription, returning it if it was found - * - * @param subscription - * - * @return null if no match was found - */ - public Subscription removeSubscriber(Subscription subscription) - { - // TODO: possibly need O(1) operation here. - - synchronized (_changeLock) - { - - if (_subscriptions.remove(subscription)) - { - _deliveryAgents.remove(subscription); - return subscription; - } - else - { - _log.error("Unable to remove subscription:" + subscription); - debugDumpSubscription(subscription); - return null; - } - } - } - - private void debugDumpSubscription(Subscription subscription) - { - if (_log.isDebugEnabled()) - { - _log.debug("Subscription " + subscription + " not found. Dumping subscriptions:"); - for (Subscription s : _subscriptions) - { - _log.debug("Subscription: " + s); - } - _log.debug("Subscription dump complete"); - } - } - - /** - * Return the next unsuspended subscription or null if not found. <p/> Performance note: This method can scan all - * items twice when looking for a subscription that is not suspended. The worst case occcurs when all subscriptions - * are suspended. However, it is does this without synchronisation and subscriptions may be added and removed - * concurrently. Also note that because of race conditions and when subscriptions are removed between calls to - * nextSubscriber, the IndexOutOfBoundsException also causes the scan to start at the beginning. - */ - public Subscription nextSubscriber(QueueEntry msg) - { - - - try - { - final Subscription result = nextSubscriberImpl(msg); - if (result == null) - { - _currentSubscriber = 0; - return nextSubscriberImpl(msg); - } - else - { - return result; - } - } - catch (IndexOutOfBoundsException e) - { - _currentSubscriber = 0; - return nextSubscriber(msg); - } - } - - private Subscription nextSubscriberImpl(QueueEntry msg) - { - if(_exclusive) - { - try - { - Subscription subscription = _subscriptions.get(0); - subscriberScanned(); - - if (!subscription.isSuspended() ) - { - if (subscription.hasInterest(msg)) - { - DeliveryAgent deliverAgent = _deliveryAgents.get(subscription); - - if (deliverAgent.ableToDeliver()) - { - if(!subscription.wouldSuspend(msg)) - { - return subscription; - } - } - } - } - } - catch(IndexOutOfBoundsException e) - { - } - return null; - } - else - { - if (_subscriptions.isEmpty()) - { - return null; - } - final ListIterator<Subscription> iterator = _subscriptions.listIterator(_currentSubscriber); - while (iterator.hasNext()) - { - - Subscription subscription = iterator.next(); - DeliveryAgent deliverAgent = _deliveryAgents.get(subscription); - ++_currentSubscriber; - subscriberScanned(); - - if (!(deliverAgent == null || subscription.isSuspended())) - { - if (subscription.hasInterest(msg) && deliverAgent.ableToDeliver()) - { - if (!subscription.wouldSuspend(msg)) - { - return subscription; - } - } - } - } - - return null; - } - } - - /** Overridden in test classes. */ - protected void subscriberScanned() - { - } - - public boolean isEmpty() - { - return _subscriptions.isEmpty(); - } - - public List<Subscription> getSubscriptions() - { - return _subscriptions; - } - - public boolean hasActiveSubscribers() - { - for (Subscription s : _subscriptions) - { - if (!s.isSuspended()) - { - return true; - } - } - return false; - } - - public int getActiveConsumerCount() - { - int count = 0; - for (Subscription s : _subscriptions) - { - if (s.isActive()) - { - count++; - } - } - return count; - } - - public int getConsumerCount() - { - return size(); - } - - /** - * Notification that a queue has been deleted. This is called so that the subscription can inform the channel, which - * in turn can update its list of unacknowledged messages. - * - * @param queue - */ - public void queueDeleted(AMQQueue queue) - { - for (Subscription s : _subscriptions) - { - s.queueDeleted(queue); - } - } - - int size() - { - return _subscriptions.size(); - } - - - public Object getChangeLock() - { - return _changeLock; - } - - public void setExclusive(final boolean exclusive) - { - _exclusive = exclusive; - } - - - public DeliveryAgent getDeliveryAgent(final Subscription sub) - { - return _deliveryAgents.get(sub); - } -} |