/**
*
* Copyright 2004 Protique Ltd
*
* 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 org.activemq.service.boundedvm;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.jms.JMSException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.activemq.broker.BrokerClient;
import org.activemq.filter.Filter;
import org.activemq.io.util.MemoryBoundedQueue;
import org.activemq.io.util.MemoryBoundedQueueManager;
import org.activemq.io.util.MemoryManageable;
import org.activemq.message.ActiveMQDestination;
import org.activemq.message.ActiveMQMessage;
import org.activemq.message.ConsumerInfo;
import org.activemq.message.MessageAck;
import org.activemq.service.DeadLetterPolicy;
import org.activemq.service.MessageContainer;
import org.activemq.service.MessageContainerAdmin;
import org.activemq.service.MessageIdentity;
import org.activemq.service.QueueListEntry;
import org.activemq.service.RedeliveryPolicy;
import org.activemq.service.Service;
import org.activemq.service.impl.DefaultQueueList;
import EDU.oswego.cs.dl.util.concurrent.Executor;
import EDU.oswego.cs.dl.util.concurrent.SynchronizedBoolean;
/**
* A MessageContainer for transient queues
*
* @version $Revision: 1.1.1.1 $
*/
public class TransientQueueBoundedMessageContainer implements MessageContainer, Service, Runnable, MessageContainerAdmin {
private MemoryBoundedQueueManager queueManager;
private ActiveMQDestination destination;
private SynchronizedBoolean started;
private SynchronizedBoolean running;
private MemoryBoundedQueue queue;
private DefaultQueueList subscriptions;
private Executor threadPool;
private Log log;
private long idleTimestamp; //length of time (ms) there have been no active subscribers
private RedeliveryPolicy redeliveryPolicy;
private DeadLetterPolicy deadLetterPolicy;
private final Object dispatchMutex = new Object();
private final Object subscriptionMutex = new Object();
/**
* Construct this beast
*
* @param threadPool
* @param queueManager
* @param destination
* @param redeliveryPolicy
* @param deadLetterPolicy
*/
public TransientQueueBoundedMessageContainer(Executor threadPool, MemoryBoundedQueueManager queueManager,
ActiveMQDestination destination,RedeliveryPolicy redeliveryPolicy, DeadLetterPolicy deadLetterPolicy) {
this.threadPool = threadPool;
this.queueManager = queueManager;
this.destination = destination;
this.redeliveryPolicy = redeliveryPolicy;
this.deadLetterPolicy = deadLetterPolicy;
this.queue = queueManager.getMemoryBoundedQueue("TRANSIENT_QUEUE:-" + destination.getPhysicalName());
this.started = new SynchronizedBoolean(false);
this.running = new SynchronizedBoolean(false);
this.subscriptions = new DefaultQueueList();
this.log = LogFactory.getLog("TransientQueueBoundedMessageContainer:- " + destination);
}
/**
* @return true if there are subscribers waiting for messages
*/
public boolean isActive(){
return !subscriptions.isEmpty();
}
/**
* @return true if no messages are enqueued
*/
public boolean isEmpty(){
return queue.isEmpty();
}
/**
* @return the timestamp (ms) from the when the last active subscriber stopped
*/
public long getIdleTimestamp(){
return idleTimestamp;
}
/**
* Add a consumer to dispatch messages to
*
* @param filter
* @param info
* @param client
* @return TransientQueueSubscription
* @throws JMSException
*/
public TransientQueueSubscription addConsumer(Filter filter,ConsumerInfo info, BrokerClient client) throws JMSException {
synchronized (subscriptionMutex) {
TransientQueueSubscription ts = findMatch(info);
if (ts == null) {
MemoryBoundedQueue queue = queueManager
.getMemoryBoundedQueue("TRANSIENT_QUEUE_SUB:-"
+ info.getConsumerId());
MemoryBoundedQueue ackQueue = queueManager
.getMemoryBoundedQueue("TRANSIENT_QUEUE_SUB_ACKED:-"
+ info.getConsumerId());
ts = new TransientQueueSubscription(client, queue, ackQueue,
filter, info);
idleTimestamp = 0;
subscriptions.add(ts);
if (started.get()) {
synchronized (running) {
if (running.commit(false, true)) {
try {
threadPool.execute(this);
} catch (InterruptedException e) {
JMSException jmsEx = new JMSException(
toString()
+ " Failed to start running dispatch thread");
jmsEx.setLinkedException(e);
throw jmsEx;
}
}
}
}
}
return ts;
}
}
/**
* Remove a consumer
*
* @param info
* @throws JMSException
*/
public void removeConsumer(ConsumerInfo info) throws JMSException {
synchronized (subscriptionMutex) {
TransientQueueSubscription ts = findMatch(info);
if (ts != null) {
subscriptions.remove(ts);
if (subscriptions.isEmpty()) {
running.commit(true, false);
idleTimestamp = System.currentTimeMillis();
}
//get unacknowledged messages and re-enqueue them
List list = ts.getUndeliveredMessages();
for (int i = list.size() - 1; i >= 0; i--) {
queue.enqueueFirstNoBlock((MemoryManageable) list.get(i));
}
// If it is a queue browser, then re-enqueue the browsed
// messages.
if (ts.isBrowser()) {
list = ts.listAckedMessages();
for (int i = list.size() - 1; i >= 0; i--) {
queue.enqueueFirstNoBlock((MemoryManageable) list
.get(i));
}
ts.removeAllAckedMessages();
}
ts.close();
}
}
}
/**
* start working
*
* @throws JMSException
*/
public void start() throws JMSException {
if (started.commit(false, true)) {
if (!subscriptions.isEmpty()) {
synchronized (running) {
if (running.commit(false, true)) {
try {
threadPool.execute(this);
}
catch (InterruptedException e) {
JMSException jmsEx = new JMSException(toString() + " Failed to start");
jmsEx.setLinkedException(e);
throw jmsEx;
}
}
}
}
}
}
/**
* enqueue a message for dispatching
*
* @param message
*/
public void enqueue(ActiveMQMessage message) {
if (message.isAdvisory()) {
doAdvisoryDispatchMessage(message);
}
else {
queue.enqueue(message);
startRunning();
}
}
/**
* re-enqueue a message for dispatching
*
* @param message
*/
public void redeliver(ActiveMQMessage message) {
queue.enqueueFirstNoBlock(message);
startRunning();
}
public void redeliver(List messages) {
queue.enqueueAllFirstNoBlock(messages);
startRunning();
}
/**
* stop working
*/
public void stop() {
started.set(false);
running.set(false);
queue.clear();
}
/**
* close down this container
*
* @throws JMSException
*/
public void close() throws JMSException {
if (started.get()) {
stop();
}
queue.close();
synchronized (subscriptionMutex) {
QueueListEntry entry = subscriptions.getFirstEntry();
while (entry != null) {
TransientQueueSubscription ts = (TransientQueueSubscription) entry
.getElement();
ts.close();
entry = subscriptions.getNextEntry(entry);
}
subscriptions.clear();
}
}
/**
* do some dispatching
*/
public void run() {
// Only allow one thread at a time to dispatch.
synchronized (dispatchMutex) {
boolean dispatched = false;
boolean targeted = false;
ActiveMQMessage message = null;
int notDispatchedCount = 0;
int sleepTime = 250;
int iterationsWithoutDispatchingBeforeStopping = 10000 / sleepTime;// ~10
// seconds
Map messageParts = new HashMap();
try {
while (started.get() && running.get()) {
dispatched = false;
targeted = false;
synchronized (subscriptionMutex) {
if (!subscriptions.isEmpty()) {
message = (ActiveMQMessage) queue
.dequeue(sleepTime);
if (message != null) {
if (!message.isExpired()) {
QueueListEntry entry = subscriptions.getFirstEntry();
while (entry != null) {
TransientQueueSubscription ts = (TransientQueueSubscription) entry.getElement();
if (ts.isTarget(message)) {
targeted = true;
if (message.isMessagePart()) {
TransientQueueSubscription sameTarget = (TransientQueueSubscription) messageParts
.get(message.getParentMessageID());
if (sameTarget == null) {
sameTarget = ts;
messageParts.put(message.getParentMessageID(),sameTarget);
}
sameTarget.doDispatch(message);
if (message.isLastMessagePart()) {
messageParts.remove(message.getParentMessageID());
}
message = null;
dispatched = true;
notDispatchedCount = 0;
break;
} else if (ts.canAcceptMessages()) {
ts.doDispatch(message);
message = null;
dispatched = true;
notDispatchedCount = 0;
subscriptions.rotate();
break;
}
}
entry = subscriptions
.getNextEntry(entry);
}
} else {
// expire message
if (log.isDebugEnabled()) {
log.debug("expired message: "+ message);
}
deadLetterPolicy.sendToDeadLetter(message);
message = null;
}
}
}
}
if (!dispatched) {
if (message != null) {
if (targeted) {
queue.enqueueFirstNoBlock(message);
} else {
//no matching subscribers - dump to end and hope one shows up ...
queue.enqueueNoBlock(message);
}
}
if (running.get()) {
if (notDispatchedCount++ > iterationsWithoutDispatchingBeforeStopping
&& queue.isEmpty()) {
synchronized (running) {
running.commit(true, false);
}
} else {
Thread.sleep(sleepTime);
}
}
}
}
} catch (InterruptedException ie) {
//someone is stopping us from another thread
} catch (Throwable e) {
log.warn("stop dispatching", e);
stop();
}
}
}
private TransientQueueSubscription findMatch(ConsumerInfo info) throws JMSException {
TransientQueueSubscription result = null;
synchronized(subscriptionMutex){
QueueListEntry entry = subscriptions.getFirstEntry();
while (entry != null) {
TransientQueueSubscription ts = (TransientQueueSubscription) entry.getElement();
if (ts.getConsumerInfo().equals(info)) {
result = ts;
break;
}
entry = subscriptions.getNextEntry(entry);
}
}
return result;
}
/**
* @return the destination associated with this container
*/
public ActiveMQDestination getDestination() {
return destination;
}
/**
* @return the destination name
*/
public String getDestinationName() {
return destination.getPhysicalName();
}
/**
* @param msg
* @return @throws JMSException
*/
public void addMessage(ActiveMQMessage msg) throws JMSException {
}
/**
* @param messageIdentity
* @param ack
* @throws JMSException
*/
public void delete(MessageIdentity messageIdentity, MessageAck ack) throws JMSException {
}
/**
* @param messageIdentity
* @return @throws JMSException
*/
public ActiveMQMessage getMessage(MessageIdentity messageIdentity) throws JMSException {
return null;
}
/**
* @param messageIdentity
* @throws JMSException
*/
public void registerMessageInterest(MessageIdentity messageIdentity) throws JMSException {
}
/**
* @param messageIdentity
* @param ack
* @throws JMSException
*/
public void unregisterMessageInterest(MessageIdentity messageIdentity) throws JMSException {
}
/**
* @param messageIdentity
* @return @throws JMSException
*/
public boolean containsMessage(MessageIdentity messageIdentity) throws JMSException {
return false;
}
protected void clear() {
queue.clear();
}
protected void removeExpiredMessages() {
long currentTime = System.currentTimeMillis();
List list = queue.getContents();
for (int i = 0;i < list.size();i++) {
ActiveMQMessage msg = (ActiveMQMessage) list.get(i);
if (msg.isExpired(currentTime)) {
queue.remove(msg);
if (log.isDebugEnabled()) {
log.debug("expired message: " + msg);
}
}
}
}
protected void startRunning(){
if (!running.get() && started.get() && !subscriptions.isEmpty()) {
synchronized (running) {
if (running.commit(false, true)) {
try {
threadPool.execute(this);
}
catch (InterruptedException e) {
log.error(this + " Couldn't start executing ",e);
}
}
}
}
}
/**
* @see org.activemq.service.MessageContainer#getMessageContainerAdmin()
*/
public MessageContainerAdmin getMessageContainerAdmin() {
return this;
}
/**
* @see org.activemq.service.MessageContainerAdmin#empty()
*/
public void empty() throws JMSException {
// TODO implement me.
}
/**
* @see org.activemq.service.MessageContainer#isDeadLetterQueue()
*/
public boolean isDeadLetterQueue() {
return false;
}
/**
* Dispatch an Advisory Message
* @param message
*/
private synchronized void doAdvisoryDispatchMessage(ActiveMQMessage message) {
try {
if (message != null && message.isAdvisory() && !message.isExpired()) {
synchronized (subscriptionMutex) {
QueueListEntry entry = subscriptions.getFirstEntry();
while (entry != null) {
TransientQueueSubscription ts = (TransientQueueSubscription) entry.getElement();
if (ts.isTarget(message)) {
ts.doDispatch(message);
break;
}
entry = subscriptions.getNextEntry(entry);
}
}
}
} catch (JMSException jmsEx) {
log.warn("Failed to dispatch advisory", jmsEx);
}
}
}