/*
* 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.felix.eventadmin.impl.handler;
import java.util.Collection;
import java.util.Iterator;
import org.apache.felix.eventadmin.impl.security.PermissionsUtil;
import org.apache.felix.eventadmin.impl.util.LogWrapper;
import org.osgi.framework.Bundle;
import org.osgi.framework.Filter;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
/**
* This is a proxy for event handlers. It gets the real event handler
* on demand and prepares some information for faster processing.
*
* It checks the timeout handling for the implementation as well as
* blacklisting the handler.
*
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class EventHandlerProxy {
/** The service reference for the event handler. */
private final ServiceReference<EventHandler> reference;
/** The handler context. */
private final EventHandlerTracker.HandlerContext handlerContext;
/** The event topics. */
private volatile String[] topics;
/** Optional filter. */
private volatile Filter filter;
/** Lazy fetched event handler. */
private volatile EventHandler handler;
/** Is this handler blacklisted? */
private volatile boolean blacklisted;
/** Use timeout. */
private boolean useTimeout;
/** Deliver async ordered. */
private boolean asyncOrderedDelivery;
/**
* Create an EventHandlerProxy.
*
* @param context The handler context
* @param reference Reference to the EventHandler
*/
public EventHandlerProxy(final EventHandlerTracker.HandlerContext context,
final ServiceReference<EventHandler> reference)
{
this.handlerContext = context;
this.reference = reference;
}
/**
* Update the state with current properties from the service
* @return <code>true</code> if the handler configuration is valid.
*/
public boolean update()
{
this.blacklisted = false;
boolean valid = true;
// First check, topic
final Object topicObj = reference.getProperty(EventConstants.EVENT_TOPIC);
if (topicObj instanceof String)
{
if ( topicObj.toString().equals("*") )
{
this.topics = null;
}
else
{
this.topics = new String[] {topicObj.toString()};
}
}
else if (topicObj instanceof String[])
{
// check if one value matches '*'
final String[] values = (String[])topicObj;
boolean matchAll = false;
for(int i=0;i<values.length;i++)
{
if ( "*".equals(values[i]) )
{
matchAll = true;
}
}
if ( matchAll )
{
this.topics = null;
}
else
{
this.topics = values;
}
}
else if (topicObj instanceof Collection)
{
@SuppressWarnings("unchecked")
final Collection<Object> col = (Collection<Object>)topicObj;
final String[] values = new String[col.size()];
int index = 0;
// check if one value matches '*'
final Iterator<Object> i = col.iterator();
boolean matchAll = false;
while ( i.hasNext() )
{
final String v = i.next().toString();
values[index] = v;
index++;
if ( "*".equals(v) )
{
matchAll = true;
}
}
if ( matchAll )
{
this.topics = null;
}
else
{
this.topics = values;
}
}
else if ( topicObj == null && !this.handlerContext.requireTopic )
{
this.topics = null;
}
else
{
final String reason;
if ( topicObj == null )
{
reason = "Missing";
}
else
{
reason = "Neither of type String nor String[] : " + topicObj.getClass().getName();
}
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Invalid EVENT_TOPICS : " + reason + " - Ignoring ServiceReference ["
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]");
this.topics = null;
valid = false;
}
// Second check filter (but only if topics is valid)
Filter handlerFilter = null;
if ( valid )
{
final Object filterObj = reference.getProperty(EventConstants.EVENT_FILTER);
if (filterObj instanceof String)
{
try
{
handlerFilter = this.handlerContext.bundleContext.createFilter(filterObj.toString());
}
catch (final InvalidSyntaxException e)
{
valid = false;
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Invalid EVENT_FILTER - Ignoring ServiceReference ["
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]", e);
}
}
else if ( filterObj != null )
{
valid = false;
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Invalid EVENT_FILTER - Ignoring ServiceReference ["
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]");
}
}
this.filter = handlerFilter;
// new in 1.3 - deliver
this.asyncOrderedDelivery = true;
Object delivery = reference.getProperty(EventConstants.EVENT_DELIVERY);
if ( delivery instanceof Collection )
{
@SuppressWarnings("unchecked")
final Collection<String> col = (Collection<String>)delivery;
delivery = col.toArray(new String[col.size()]);
}
if ( delivery instanceof String )
{
this.asyncOrderedDelivery = !(EventConstants.DELIVERY_ASYNC_UNORDERED.equals(delivery.toString()));
}
else if ( delivery instanceof String[] )
{
final String[] deliveryArray = (String[])delivery;
boolean foundOrdered = false, foundUnordered = false;
for(int i=0; i<deliveryArray.length; i++)
{
final String value = deliveryArray[i];
if ( EventConstants.DELIVERY_ASYNC_UNORDERED.equals(value) )
{
foundUnordered = true;
}
else if ( EventConstants.DELIVERY_ASYNC_ORDERED.equals(value) )
{
foundOrdered = true;
}
else
{
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Invalid EVENT_DELIVERY - Ignoring invalid value for event delivery property " + value + " of ServiceReference ["
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]");
}
}
if ( !foundOrdered && foundUnordered )
{
this.asyncOrderedDelivery = false;
}
}
else if ( delivery != null )
{
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Invalid EVENT_DELIVERY - Ignoring event delivery property " + delivery + " of ServiceReference ["
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]");
}
// make sure to release the handler
this.release();
return valid;
}
/**
* Dispose the proxy and release the handler
*/
public void dispose()
{
this.release();
}
/**
* Get the event handler.
*/
private synchronized EventHandler obtain() {
if (this.handler == null)
{
try
{
this.handler = this.handlerContext.bundleContext.getService(this.reference);
if ( this.handler != null )
{
this.checkTimeout(this.handler.getClass().getName());
}
}
catch (final IllegalStateException ignore)
{
// event handler might be stopped - ignore
}
}
return this.handler;
}
/**
* Release the handler
*/
private synchronized void release()
{
if ( this.handler != null )
{
try
{
this.handlerContext.bundleContext.ungetService(this.reference);
}
catch (final IllegalStateException ignore)
{
// event handler might be stopped - ignore
}
this.handler = null;
}
}
/**
* Get the topics of this handler.
* If this handler matches all topics <code>null</code> is returned
*/
public String[] getTopics()
{
return this.topics;
}
/**
* Check if this handler is allowed to receive the event
* - blacklisted
* - check filter
* - check permission
*/
public boolean canDeliver(final Event event)
{
if ( this.blacklisted )
{
return false;
}
final Bundle bundle = reference.getBundle();
// is service unregistered?
if (bundle == null)
{
return false;
}
// filter match
final Filter eventFilter = this.filter;
if ( eventFilter != null && !event.matches(eventFilter) )
{
return false;
}
// permission check
final Object p = PermissionsUtil.createSubscribePermission(event.getTopic());
if (p != null && !bundle.hasPermission(p) )
{
return false;
}
return true;
}
/**
* Should a timeout be used for this handler?
*/
public boolean useTimeout()
{
return this.useTimeout;
}
/**
* Should async events be delivered in order?
*/
public boolean isAsyncOrderedDelivery()
{
return this.asyncOrderedDelivery;
}
/**
* Check the timeout configuration for this handler.
*/
private void checkTimeout(final String className)
{
if ( this.handlerContext.ignoreTimeoutMatcher != null )
{
for(int i=0;i<this.handlerContext.ignoreTimeoutMatcher.length;i++)
{
if ( this.handlerContext.ignoreTimeoutMatcher[i] != null)
{
if ( this.handlerContext.ignoreTimeoutMatcher[i].match(className) )
{
this.useTimeout = false;
return;
}
}
}
}
this.useTimeout = true;
}
/**
* Send the event.
*/
public void sendEvent(final Event event)
{
final EventHandler handlerService = this.obtain();
if (handlerService == null)
{
return;
}
try
{
handlerService.handleEvent(event);
}
catch (final Throwable e)
{
// The spec says that we must catch exceptions and log them:
LogWrapper.getLogger().log(
this.reference,
LogWrapper.LOG_WARNING,
"Exception during event dispatch [" + event + " | "
+ this.reference + " | Bundle("
+ this.reference.getBundle() + ")]", e);
}
}
/**
* Blacklist the handler.
*/
public void blackListHandler()
{
if(!this.blacklisted)
{
LogWrapper.getLogger().log(
LogWrapper.LOG_WARNING,
"Blacklisting ServiceReference [" + this.reference + " | Bundle("
+ this.reference.getBundle() + ")] due to timeout!");
this.blacklisted = true;
// we can free the handler now.
this.release();
}
}
}