/**
* 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.activemq.broker.region.cursors;
import static org.apache.activemq.broker.region.cursors.OrderedPendingList.getValues;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.Deque;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.activemq.broker.region.MessageReference;
import org.apache.activemq.command.MessageId;
import org.apache.activemq.management.SizeStatisticImpl;
public class PrioritizedPendingList implements PendingList {
private static final Integer MAX_PRIORITY = 10;
private final OrderedPendingList[] lists = new OrderedPendingList[MAX_PRIORITY];
private final Map<MessageId, PendingNode> map = new HashMap<MessageId, PendingNode>();
private final SizeStatisticImpl messageSize;
private final PendingMessageHelper pendingMessageHelper;
public PrioritizedPendingList() {
for (int i = 0; i < MAX_PRIORITY; i++) {
this.lists[i] = new OrderedPendingList();
}
messageSize = new SizeStatisticImpl("messageSize", "The size in bytes of the pending messages");
messageSize.setEnabled(true);
pendingMessageHelper = new PendingMessageHelper(map, messageSize);
}
@Override
public PendingNode addMessageFirst(MessageReference message) {
PendingNode node = getList(message).addMessageFirst(message);
this.pendingMessageHelper.addToMap(message, node);
return node;
}
@Override
public PendingNode addMessageLast(MessageReference message) {
PendingNode node = getList(message).addMessageLast(message);
this.pendingMessageHelper.addToMap(message, node);
return node;
}
@Override
public void clear() {
for (int i = 0; i < MAX_PRIORITY; i++) {
this.lists[i].clear();
}
this.map.clear();
this.messageSize.reset();
}
@Override
public boolean isEmpty() {
return this.map.isEmpty();
}
@Override
public Iterator<MessageReference> iterator() {
return new PrioritizedPendingListIterator();
}
@Override
public PendingNode remove(MessageReference message) {
PendingNode node = null;
if (message != null) {
node = this.pendingMessageHelper.removeFromMap(message);
if (node != null) {
node.getList().removeNode(node);
}
}
return node;
}
@Override
public int size() {
return this.map.size();
}
@Override
public long messageSize() {
return this.messageSize.getTotalSize();
}
@Override
public String toString() {
return "PrioritizedPendingList(" + System.identityHashCode(this) + ")";
}
protected int getPriority(MessageReference message) {
int priority = javax.jms.Message.DEFAULT_PRIORITY;
if (message.getMessageId() != null) {
priority = Math.max(message.getMessage().getPriority(), 0);
priority = Math.min(priority, 9);
}
return priority;
}
protected OrderedPendingList getList(MessageReference msg) {
return lists[getPriority(msg)];
}
private final class PrioritizedPendingListIterator implements Iterator<MessageReference> {
private final Deque<Iterator<MessageReference>> iterators = new ArrayDeque<Iterator<MessageReference>>();
private Iterator<MessageReference> current;
private MessageReference currentMessage;
PrioritizedPendingListIterator() {
for (OrderedPendingList list : lists) {
if (!list.isEmpty()) {
iterators.push(list.iterator());
}
}
current = iterators.poll();
}
@Override
public boolean hasNext() {
while (current != null) {
if (current.hasNext()) {
return true;
} else {
current = iterators.poll();
}
}
return false;
}
@Override
public MessageReference next() {
MessageReference result = null;
while (current != null) {
if (current.hasNext()) {
result = currentMessage = current.next();
break;
} else {
current = iterators.poll();
}
}
return result;
}
@Override
public void remove() {
if (currentMessage != null) {
pendingMessageHelper.removeFromMap(currentMessage);
current.remove();
currentMessage = null;
}
}
}
@Override
public boolean contains(MessageReference message) {
if (message != null) {
return this.map.containsKey(message.getMessageId());
}
return false;
}
@Override
public Collection<MessageReference> values() {
return getValues(this);
}
@Override
public void addAll(PendingList pendingList) {
for(MessageReference messageReference : pendingList) {
addMessageLast(messageReference);
}
}
@Override
public MessageReference get(MessageId messageId) {
PendingNode node = map.get(messageId);
if (node != null) {
return node.getMessage();
}
return null;
}
}