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*
* 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.
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*/
package org.apache.qpid.server.exchange;
import org.apache.log4j.Logger;
import org.apache.qpid.AMQException;
import org.apache.qpid.exchange.ExchangeDefaults;
import org.apache.qpid.framing.AMQShortString;
import org.apache.qpid.framing.FieldTable;
import org.apache.qpid.server.queue.AMQQueue;
import org.apache.qpid.server.queue.BaseQueue;
import org.apache.qpid.server.virtualhost.VirtualHost;
import org.apache.qpid.server.message.InboundMessage;
import org.apache.qpid.server.message.AMQMessageHeader;
import org.apache.qpid.server.binding.Binding;
import javax.management.JMException;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
/**
* An exchange that binds queues based on a set of required headers and header values
* and routes messages to these queues by matching the headers of the message against
* those with which the queues were bound.
* <p/>
* <pre>
* The Headers Exchange
*
* Routes messages according to the value/presence of fields in the message header table.
* (Basic and JMS content has a content header field called "headers" that is a table of
* message header fields).
*
* class = "headers"
* routing key is not used
*
* Has the following binding arguments:
*
* the X-match field - if "all", does an AND match (used for GRM), if "any", does an OR match.
* other fields prefixed with "X-" are ignored (and generate a console warning message).
* a field with no value or empty value indicates a match on presence only.
* a field with a value indicates match on field presence and specific value.
*
* Standard instances:
*
* amq.match - pub/sub on field content/value
* </pre>
*/
public class HeadersExchange extends AbstractExchange
{
private static final Logger _logger = Logger.getLogger(HeadersExchange.class);
private final ConcurrentHashMap<String, CopyOnWriteArraySet<Binding>> _bindingsByKey =
new ConcurrentHashMap<String, CopyOnWriteArraySet<Binding>>();
private final CopyOnWriteArrayList<HeadersBinding> _bindingHeaderMatchers =
new CopyOnWriteArrayList<HeadersBinding>();
public static final ExchangeType<HeadersExchange> TYPE = new ExchangeType<HeadersExchange>()
{
public AMQShortString getName()
{
return ExchangeDefaults.HEADERS_EXCHANGE_CLASS;
}
public Class<HeadersExchange> getExchangeClass()
{
return HeadersExchange.class;
}
public HeadersExchange newInstance(VirtualHost host, AMQShortString name, boolean durable, int ticket,
boolean autoDelete) throws AMQException
{
HeadersExchange exch = new HeadersExchange();
exch.initialise(host, name, durable, ticket, autoDelete);
return exch;
}
public AMQShortString getDefaultExchangeName()
{
return ExchangeDefaults.HEADERS_EXCHANGE_NAME;
}
};
public HeadersExchange()
{
super(TYPE);
}
public ArrayList<BaseQueue> doRoute(InboundMessage payload)
{
AMQMessageHeader header = payload.getMessageHeader();
if (_logger.isDebugEnabled())
{
_logger.debug("Exchange " + getNameShortString() + ": routing message with headers " + header);
}
LinkedHashSet<BaseQueue> queues = new LinkedHashSet<BaseQueue>();
for (HeadersBinding hb : _bindingHeaderMatchers)
{
if (hb.matches(header))
{
Binding b = hb.getBinding();
b.incrementMatches();
if (_logger.isDebugEnabled())
{
_logger.debug("Exchange " + getNameShortString() + ": delivering message with headers " +
header + " to " + b.getQueue().getNameShortString());
}
queues.add(b.getQueue());
}
}
return new ArrayList<BaseQueue>(queues);
}
public boolean isBound(AMQShortString routingKey, FieldTable arguments, AMQQueue queue)
{
//fixme isBound here should take the arguements in to consideration.
return isBound(routingKey, queue);
}
public boolean isBound(AMQShortString routingKey, AMQQueue queue)
{
String bindingKey = (routingKey == null) ? "" : routingKey.toString();
CopyOnWriteArraySet<Binding> bindings = _bindingsByKey.get(bindingKey);
if(bindings != null)
{
for(Binding binding : bindings)
{
if(binding.getQueue().equals(queue))
{
return true;
}
}
}
return false;
}
public boolean isBound(AMQShortString routingKey)
{
String bindingKey = (routingKey == null) ? "" : routingKey.toString();
CopyOnWriteArraySet<Binding> bindings = _bindingsByKey.get(bindingKey);
return bindings != null && !bindings.isEmpty();
}
public boolean isBound(AMQQueue queue)
{
for (CopyOnWriteArraySet<Binding> bindings : _bindingsByKey.values())
{
for(Binding binding : bindings)
{
if(binding.getQueue().equals(queue))
{
return true;
}
}
}
return false;
}
public boolean hasBindings()
{
return !getBindings().isEmpty();
}
protected AbstractExchangeMBean createMBean() throws JMException
{
return new HeadersExchangeMBean(this);
}
public Logger getLogger()
{
return _logger;
}
protected void onBind(final Binding binding)
{
String bindingKey = binding.getBindingKey();
AMQQueue queue = binding.getQueue();
AMQShortString routingKey = AMQShortString.valueOf(bindingKey);
Map<String,Object> args = binding.getArguments();
assert queue != null;
assert routingKey != null;
CopyOnWriteArraySet<Binding> bindings = _bindingsByKey.get(bindingKey);
if(bindings == null)
{
bindings = new CopyOnWriteArraySet<Binding>();
CopyOnWriteArraySet<Binding> newBindings;
if((newBindings = _bindingsByKey.putIfAbsent(bindingKey, bindings)) != null)
{
bindings = newBindings;
}
}
if(_logger.isDebugEnabled())
{
_logger.debug("Exchange " + getNameShortString() + ": Binding " + queue.getNameShortString() +
" with binding key '" +bindingKey + "' and args: " + args);
}
_bindingHeaderMatchers.add(new HeadersBinding(binding));
bindings.add(binding);
}
protected void onUnbind(final Binding binding)
{
assert binding != null;
CopyOnWriteArraySet<Binding> bindings = _bindingsByKey.get(binding.getBindingKey());
if(bindings != null)
{
bindings.remove(binding);
}
if(_logger.isDebugEnabled())
{
_logger.debug("Removing Binding: " + _bindingHeaderMatchers.remove(new HeadersBinding(binding)));
}
}
}