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Diffstat (limited to 'bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/serviceregistry/FilteredServiceListener.java')
| -rw-r--r-- | bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/serviceregistry/FilteredServiceListener.java | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/serviceregistry/FilteredServiceListener.java b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/serviceregistry/FilteredServiceListener.java new file mode 100644 index 000000000..528d8d2e6 --- /dev/null +++ b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/serviceregistry/FilteredServiceListener.java @@ -0,0 +1,205 @@ +/******************************************************************************* + * Copyright (c) 2003, 2010 IBM Corporation and others. + * All rights reserved. This program and the accompanying materials + * are made available under the terms of the Eclipse Public License v1.0 + * which accompanies this distribution, and is available at + * http://www.eclipse.org/legal/epl-v10.html + * + * Contributors: + * IBM Corporation - initial API and implementation + *******************************************************************************/ + +package org.eclipse.osgi.internal.serviceregistry; + +import org.eclipse.osgi.framework.debug.Debug; +import org.eclipse.osgi.framework.internal.core.BundleContextImpl; +import org.eclipse.osgi.framework.internal.core.FilterImpl; +import org.osgi.framework.*; +import org.osgi.framework.hooks.service.ListenerHook; + +/** + * Service Listener delegate. + */ +class FilteredServiceListener implements ServiceListener, ListenerHook.ListenerInfo { + /** Filter for listener. */ + private final FilterImpl filter; + /** Real listener. */ + private final ServiceListener listener; + /** The bundle context */ + private final BundleContextImpl context; + /** is this an AllServiceListener */ + private final boolean allservices; + /** is this an UnfilteredServiceListener */ + private final boolean unfiltered; + /** an objectClass required by the filter */ + private final String objectClass; + /** indicates whether the listener has been removed */ + private volatile boolean removed; + + /** + * Constructor. + * + * @param context The bundle context of the bundle which added the specified service listener. + * @param filterstring The filter string specified when this service listener was added. + * @param listener The service listener object. + * @exception InvalidSyntaxException if the filter is invalid. + */ + FilteredServiceListener(final BundleContextImpl context, final ServiceListener listener, final String filterstring) throws InvalidSyntaxException { + this.unfiltered = (listener instanceof UnfilteredServiceListener); + if (filterstring == null) { + this.filter = null; + this.objectClass = null; + } else { + FilterImpl filterImpl = FilterImpl.newInstance(filterstring); + String clazz = filterImpl.getRequiredObjectClass(); + if (unfiltered || (clazz == null)) { + this.objectClass = null; + this.filter = filterImpl; + } else { + this.objectClass = clazz.intern(); /*intern the name for future identity comparison */ + this.filter = filterstring.equals(getObjectClassFilterString(this.objectClass)) ? null : filterImpl; + } + } + this.removed = false; + this.listener = listener; + this.context = context; + this.allservices = (listener instanceof AllServiceListener); + } + + /** + * Receives notification that a service has had a lifecycle change. + * + * @param event The <code>ServiceEvent</code> object. + */ + public void serviceChanged(ServiceEvent event) { + ServiceReferenceImpl<?> reference = (ServiceReferenceImpl<?>) event.getServiceReference(); + + // first check if we can short circuit the filter match if the required objectClass does not match the event + objectClassCheck: if (objectClass != null) { + String[] classes = reference.getClasses(); + int size = classes.length; + for (int i = 0; i < size; i++) { + if (classes[i] == objectClass) // objectClass strings have previously been interned for identity comparison + break objectClassCheck; + } + return; // no class in this event matches a required part of the filter; we do not need to deliver this event + } + // TODO could short circuit service.id filters as well since the id is constant for a registration. + + if (!ServiceRegistry.hasListenServicePermission(event, context)) + return; + + if (Debug.DEBUG_EVENTS) { + String listenerName = this.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(this)); //$NON-NLS-1$ + Debug.println("filterServiceEvent(" + listenerName + ", \"" + getFilter() + "\", " + reference.getRegistration().getProperties() + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ + } + + event = filterMatch(event); + if (event == null) { + return; + } + if (allservices || ServiceRegistry.isAssignableTo(context, reference)) { + if (Debug.DEBUG_EVENTS) { + String listenerName = listener.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(listener)); //$NON-NLS-1$ + Debug.println("dispatchFilteredServiceEvent(" + listenerName + ")"); //$NON-NLS-1$ //$NON-NLS-2$ + } + + listener.serviceChanged(event); + } + } + + /** + * Returns a service event that should be delivered to the listener based on the filter evaluation. + * This may result in a service event of type MODIFIED_ENDMATCH. + * + * @param delivered The service event delivered by the framework. + * @return The event to be delivered or null if no event is to be delivered to the listener. + */ + private ServiceEvent filterMatch(ServiceEvent delivered) { + boolean modified = delivered.getType() == ServiceEvent.MODIFIED; + ServiceEvent event = modified ? ((ModifiedServiceEvent) delivered).getModifiedEvent() : delivered; + if (unfiltered || (filter == null)) { + return event; + } + ServiceReference<?> reference = event.getServiceReference(); + if (filter.match(reference)) { + return event; + } + if (modified) { + ModifiedServiceEvent modifiedServiceEvent = (ModifiedServiceEvent) delivered; + if (modifiedServiceEvent.matchPreviousProperties(filter)) { + return modifiedServiceEvent.getModifiedEndMatchEvent(); + } + } + // does not match and did not match previous properties; do not send event + return null; + } + + /** + * The string representation of this Filtered listener. + * + * @return The string representation of this listener. + */ + public String toString() { + String filterString = getFilter(); + if (filterString == null) { + filterString = ""; //$NON-NLS-1$ + } + return listener.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(listener)) + filterString; //$NON-NLS-1$ + } + + /** + * Return the bundle context for the ListenerHook. + * @return The context of the bundle which added the service listener. + * @see org.osgi.framework.hooks.service.ListenerHook.ListenerInfo#getBundleContext() + */ + public BundleContext getBundleContext() { + return context; + } + + /** + * Return the filter string for the ListenerHook. + * @return The filter string with which the listener was added. This may + * be <code>null</code> if the listener was added without a filter. + * @see org.osgi.framework.hooks.service.ListenerHook.ListenerInfo#getFilter() + */ + public String getFilter() { + if (filter != null) { + return filter.toString(); + } + return getObjectClassFilterString(objectClass); + } + + /** + * Return the state of the listener for this addition and removal life + * cycle. Initially this method will return <code>false</code> + * indicating the listener has been added but has not been removed. + * After the listener has been removed, this method must always return + * <code>true</code>. + * + * @return <code>false</code> if the listener has not been been removed, + * <code>true</code> otherwise. + */ + public boolean isRemoved() { + return removed; + } + + /** + * Mark the service listener registration as removed. + */ + void markRemoved() { + removed = true; + } + + /** + * Returns an objectClass filter string for the specified class name. + * @return A filter string for the specified class name or <code>null</code> if the + * specified class name is <code>null</code>. + */ + private static String getObjectClassFilterString(String className) { + if (className == null) { + return null; + } + return "(" + Constants.OBJECTCLASS + "=" + className + ")"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$ + } +} |