/*
* 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.openjpa.event;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import org.apache.openjpa.meta.ClassMetaData;
import org.apache.openjpa.meta.MetaDataDefaults;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.util.InvalidStateException;
/**
* Manager that can be used to track and notify listeners on lifecycle events.
* This class is optimized for event firing rather than for adding and
* removing listeners, which are O(n) operations. This class also does not
* maintain perfect set semantics for listeners; it is possible to wind up
* having the same listener invoked multiple times for a single event if it
* is added to this manager multiple times with different classes, or with
* a base class and its subclass.
*
* @author Steve Kim
* @author Abe White
* @since 0.3.3
*/
@SuppressWarnings("serial")
public class LifecycleEventManager
implements CallbackModes, Serializable {
private static final Exception[] EMPTY_EXCEPTIONS = new Exception[0];
private static final Localizer _loc = Localizer.forPackage(
LifecycleEventManager.class);
private Map<Class<?>, ListenerList> _classListeners = null;
private ListenerList _listeners = null;
// odd-element: Listener even-element: Class[]
private List<Object> _addListeners = new LinkedList<Object>();
private List<Object> _remListeners = new LinkedList<Object>();
private List<Exception> _exceps = new LinkedList<Exception>();
private boolean _firing = false;
private boolean _fail = false;
private boolean _failFast = false;
private boolean _activated = false; // set to true once modified
/**
* Whether this LifeCycleEventManager has had at least one listener or callback
* registered. Used for a quick test when firing events.
* @return boolean
*/
public boolean isActive(ClassMetaData meta) {
return _activated ||
meta.getLifecycleMetaData().is_activated() ||
meta.getRepository().is_systemListenersActivated();
}
/**
* Whether to fail after first exception when firing events to listeners.
*/
public boolean isFailFast() {
return _failFast;
}
/**
* Whether to fail after first exception when firing events to listeners.
*/
public void setFailFast(boolean failFast) {
_failFast = failFast;
}
/**
* Register a lifecycle listener for the given classes. If the classes
* array is null, register for all classes.
*/
public synchronized void addListener(Object listener, Class<?>[] classes) {
if (listener == null)
return;
if (classes != null && classes.length == 0)
return;
_activated = true;
if (_firing) {
_addListeners.add(listener);
_addListeners.add(classes);
return;
}
if (classes == null) {
if (_listeners == null)
_listeners = new ListenerList(5);
_listeners.add(listener);
return;
}
if (_classListeners == null)
_classListeners = new HashMap<Class<?>, ListenerList>();
ListenerList listeners;
for (int i = 0; i < classes.length; i++) {
listeners = (ListenerList) _classListeners.get(classes[i]);
if (listeners == null) {
listeners = new ListenerList(3);
_classListeners.put(classes[i], listeners);
}
listeners.add(listener);
}
}
/**
* Remove the given listener.
*/
public synchronized void removeListener(Object listener) {
if (_firing) {
_remListeners.add(listener);
return;
}
if (_listeners != null && _listeners.remove(listener))
return;
if (_classListeners != null) {
ListenerList listeners;
for (Iterator<ListenerList> itr = _classListeners.values().iterator();
itr.hasNext();) {
listeners = (ListenerList) itr.next();
listeners.remove(listener);
}
}
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasPersistListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_PERSIST)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_PERSIST)
|| hasHandlers(source, meta,
LifecycleEvent.AFTER_PERSIST_PERFORMED);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasDeleteListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_DELETE)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_DELETE)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_DELETE_PERFORMED);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasClearListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_CLEAR)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_CLEAR);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasLoadListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.AFTER_LOAD);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasStoreListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_STORE)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_STORE);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasUpdateListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_UPDATE)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_UPDATE_PERFORMED);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasDirtyListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_DIRTY)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_DIRTY);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasDetachListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_DETACH)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_DETACH);
}
/**
* Return whether there are listeners or callbacks for the given source.
*/
public boolean hasAttachListeners(Object source, ClassMetaData meta) {
return hasHandlers(source, meta, LifecycleEvent.BEFORE_ATTACH)
|| hasHandlers(source, meta, LifecycleEvent.AFTER_ATTACH);
}
private boolean hasHandlers(Object source, ClassMetaData meta, int type) {
return hasCallbacks(source, meta, type)
|| hasListeners(source, meta, type);
}
/**
* Return true if any callbacks are registered for the given source and
* event type.
*/
private boolean hasCallbacks(Object source, ClassMetaData meta, int type) {
LifecycleCallbacks[] callbacks = meta.getLifecycleMetaData().
getCallbacks(type);
if (callbacks.length == 0)
return false;
for (int i = 0; i < callbacks.length; i++)
if (callbacks[i].hasCallback(source, type))
return true;
return false;
}
/**
* Return true if any listeners are registered for the given source and
* event type.
*/
private boolean hasListeners(Object source,
ClassMetaData meta, int type) {
if (meta.getLifecycleMetaData().getIgnoreSystemListeners())
return false;
if (fireEvent(null, source, null, type, _listeners, true, null) == Boolean.TRUE)
return true;
ListenerList system = meta.getRepository().getSystemListeners();
if (!system.isEmpty() && fireEvent(null, source, null, type, system,
true, null) == Boolean.TRUE)
return true;
if (_classListeners != null) {
Class<?> c = source == null ? meta.getDescribedType() : source.getClass();
do {
if (fireEvent(null, source, null, type, (ListenerList)
_classListeners.get(c), true, null) == Boolean.TRUE)
return true;
c = c.getSuperclass();
} while (c != null && c != Object.class);
}
return false;
}
/**
* Fire lifecycle event to all registered listeners without an argument.
*/
public Exception[] fireEvent(Object source,
ClassMetaData meta, int type) {
return fireEvent(source, null, meta, type);
}
/**
* Fire lifecycle event to all registered listeners.
*/
public synchronized Exception[] fireEvent(Object source, Object related,
ClassMetaData meta, int type) {
boolean reentrant = _firing;
_firing = true;
List<Exception> exceptions = (reentrant) ? new LinkedList<Exception>() : _exceps;
MetaDataDefaults def = meta.getRepository().getMetaDataFactory().
getDefaults();
boolean callbacks = def.getCallbacksBeforeListeners(type);
if (callbacks)
makeCallbacks(source, related, meta, type, exceptions);
LifecycleEvent ev = (LifecycleEvent) fireEvent(null, source, related,
type, _listeners, false, exceptions);
if (_classListeners != null) {
Class<?> c = source == null ? meta.getDescribedType() : source.getClass();
do {
ev = (LifecycleEvent) fireEvent(ev, source, related, type,
(ListenerList) _classListeners.get(c), false, exceptions);
c = c.getSuperclass();
} while (c != null && c != Object.class);
}
// make system listeners
if (!meta.getLifecycleMetaData().getIgnoreSystemListeners()) {
ListenerList system = meta.getRepository().getSystemListeners();
fireEvent(ev, source, related, type, system, false, exceptions);
}
if (!callbacks)
makeCallbacks(source, related, meta, type, exceptions);
// create return array before clearing exceptions
Exception[] ret;
if (exceptions.isEmpty())
ret = EMPTY_EXCEPTIONS;
else
ret = (Exception[]) exceptions.toArray
(new Exception[exceptions.size()]);
// if this wasn't a reentrant call, catch up with calls to add
// and remove listeners made while firing
if (!reentrant) {
_firing = false;
_fail = false;
if (!_addListeners.isEmpty())
for (Iterator<Object> itr = _addListeners.iterator(); itr.hasNext();)
addListener(itr.next(), (Class[]) itr.next());
if (!_remListeners.isEmpty())
for (Iterator<Object> itr = _remListeners.iterator(); itr.hasNext();)
removeListener(itr.next());
_addListeners.clear();
_remListeners.clear();
_exceps.clear();
}
return ret;
}
/**
* Make callbacks, recording any exceptions in the given collection.
*/
private void makeCallbacks(Object source, Object related,
ClassMetaData meta, int type, Collection<Exception> exceptions) {
// make lifecycle callbacks
LifecycleCallbacks[] callbacks = meta.getLifecycleMetaData().
getCallbacks(type);
for (int i = 0; !_fail && i < callbacks.length; i++) {
try {
callbacks[i].makeCallback(source, related, type);
} catch (Exception e) {
exceptions.add(e);
if (_failFast)
_fail = true;
}
}
}
/**
* Fire an event with the given source and type to the given list of
* listeners. The event may have already been constructed.
*/
private Object fireEvent(LifecycleEvent ev, Object source, Object rel,
int type, ListenerList listeners, boolean mock, List<Exception> exceptions) {
if (listeners == null || !listeners.hasListeners(type))
return null;
Object listener;
boolean responds;
for (int i = 0, size = listeners.size(); !_fail && i < size; i++) {
listener = listeners.get(i);
if (size == 1)
responds = true;
else if (listener instanceof ListenerAdapter) {
responds = ((ListenerAdapter) listener).respondsTo(type);
if (!responds)
continue;
} else {
responds = false;
}
try {
switch (type) {
case LifecycleEvent.BEFORE_CLEAR:
case LifecycleEvent.AFTER_CLEAR:
if (responds || listener instanceof ClearListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
if (type == LifecycleEvent.BEFORE_CLEAR)
((ClearListener) listener).beforeClear(ev);
else
((ClearListener) listener).afterClear(ev);
}
break;
case LifecycleEvent.BEFORE_PERSIST:
case LifecycleEvent.AFTER_PERSIST:
if (responds || listener instanceof PersistListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
if (type == LifecycleEvent.BEFORE_PERSIST)
((PersistListener) listener).beforePersist(ev);
else
((PersistListener) listener).afterPersist(ev);
}
break;
case LifecycleEvent.BEFORE_DELETE:
case LifecycleEvent.AFTER_DELETE:
if (responds || listener instanceof DeleteListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
if (type == LifecycleEvent.BEFORE_DELETE)
((DeleteListener) listener).beforeDelete(ev);
else
((DeleteListener) listener).afterDelete(ev);
}
break;
case LifecycleEvent.BEFORE_DIRTY:
case LifecycleEvent.AFTER_DIRTY:
case LifecycleEvent.BEFORE_DIRTY_FLUSHED:
case LifecycleEvent.AFTER_DIRTY_FLUSHED:
if (responds || listener instanceof DirtyListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
switch (type) {
case LifecycleEvent.BEFORE_DIRTY:
((DirtyListener) listener).beforeDirty(ev);
break;
case LifecycleEvent.AFTER_DIRTY:
((DirtyListener) listener).afterDirty(ev);
break;
case LifecycleEvent.BEFORE_DIRTY_FLUSHED:
((DirtyListener) listener)
.beforeDirtyFlushed(ev);
break;
case LifecycleEvent.AFTER_DIRTY_FLUSHED:
((DirtyListener) listener)
.afterDirtyFlushed(ev);
break;
}
}
break;
case LifecycleEvent.AFTER_LOAD:
case LifecycleEvent.AFTER_REFRESH:
if (responds || listener instanceof LoadListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
if (type == LifecycleEvent.AFTER_LOAD)
((LoadListener) listener).afterLoad(ev);
else
((LoadListener) listener).afterRefresh(ev);
}
break;
case LifecycleEvent.BEFORE_STORE:
case LifecycleEvent.AFTER_STORE:
if (responds || listener instanceof StoreListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, type);
if (type == LifecycleEvent.BEFORE_STORE)
((StoreListener) listener).beforeStore(ev);
else
((StoreListener) listener).afterStore(ev);
}
break;
case LifecycleEvent.BEFORE_DETACH:
case LifecycleEvent.AFTER_DETACH:
if (responds || listener instanceof DetachListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, rel, type);
if (type == LifecycleEvent.BEFORE_DETACH)
((DetachListener) listener).beforeDetach(ev);
else
((DetachListener) listener).afterDetach(ev);
}
break;
case LifecycleEvent.BEFORE_ATTACH:
case LifecycleEvent.AFTER_ATTACH:
if (responds || listener instanceof AttachListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, rel, type);
if (type == LifecycleEvent.BEFORE_ATTACH)
((AttachListener) listener).beforeAttach(ev);
else
((AttachListener) listener).afterAttach(ev);
}
break;
case LifecycleEvent.AFTER_PERSIST_PERFORMED:
if (responds || listener instanceof PostPersistListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, rel, type);
((PostPersistListener) listener).afterPersistPerformed(ev);
}
break;
case LifecycleEvent.BEFORE_UPDATE:
case LifecycleEvent.AFTER_UPDATE_PERFORMED:
if (responds || listener instanceof UpdateListener) {
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, rel, type);
if (type == LifecycleEvent.BEFORE_UPDATE)
((UpdateListener) listener).beforeUpdate(ev);
else
((UpdateListener) listener).afterUpdatePerformed(ev);
}
break;
case LifecycleEvent.AFTER_DELETE_PERFORMED:
if (responds || listener instanceof PostDeleteListener){
if (mock)
return Boolean.TRUE;
if (ev == null)
ev = new LifecycleEvent(source, rel, type);
((PostDeleteListener) listener).afterDeletePerformed(ev);
}
break;
default:
throw new InvalidStateException(_loc.get("unknown-lifecycle-event", Integer.toString(type)));
}
}
catch (Exception e) {
exceptions.add(e);
if (_failFast)
_fail = true;
}
}
return ev;
}
/**
* Interface that facades to other lifecycle listener interfaces can
* implement to choose which events to respond to based on their delegate.
* This is more efficient than registering as a listener for all events
* but only responding to some.
*/
public static interface ListenerAdapter {
/**
* Return whether this instance responds to the given event type from
* {@link LifecycleEvent}.
*/
public boolean respondsTo(int eventType);
}
/**
* Extended list that tracks what event types its elements care about.
* Maintains set semantics as well.
*/
public static class ListenerList extends ArrayList<Object> {
private int _types = 0;
public ListenerList(int size) {
super(size);
}
public ListenerList(ListenerList copy) {
super(copy);
_types = copy._types;
}
public boolean hasListeners(int type) {
return (_types & (2 << type)) > 0;
}
public boolean add(Object listener) {
if (contains(listener))
return false;
super.add(listener);
_types |= getEventTypes(listener);
return true;
}
public boolean remove(Object listener) {
if (!super.remove(listener))
return false;
// recompute types mask
_types = 0;
for (int i = 0; i < size(); i++)
_types |= getEventTypes(get(i));
return true;
}
/**
* Return a mask of the event types the given listener processes.
*/
private static int getEventTypes(Object listener) {
int types = 0;
if (listener instanceof ListenerAdapter) {
ListenerAdapter adapter = (ListenerAdapter) listener;
for (int i = 0; i < LifecycleEvent.ALL_EVENTS.length; i++)
if (adapter.respondsTo(LifecycleEvent.ALL_EVENTS[i]))
types |= 2 << LifecycleEvent.ALL_EVENTS[i];
return types;
}
if (listener instanceof PersistListener) {
types |= 2 << LifecycleEvent.BEFORE_PERSIST;
types |= 2 << LifecycleEvent.AFTER_PERSIST;
}
if (listener instanceof ClearListener) {
types |= 2 << LifecycleEvent.BEFORE_CLEAR;
types |= 2 << LifecycleEvent.AFTER_CLEAR;
}
if (listener instanceof DeleteListener) {
types |= 2 << LifecycleEvent.BEFORE_DELETE;
types |= 2 << LifecycleEvent.AFTER_DELETE;
}
if (listener instanceof DirtyListener) {
types |= 2 << LifecycleEvent.BEFORE_DIRTY;
types |= 2 << LifecycleEvent.AFTER_DIRTY;
types |= 2 << LifecycleEvent.BEFORE_DIRTY_FLUSHED;
types |= 2 << LifecycleEvent.AFTER_DIRTY_FLUSHED;
}
if (listener instanceof LoadListener) {
types |= 2 << LifecycleEvent.AFTER_LOAD;
types |= 2 << LifecycleEvent.AFTER_REFRESH;
}
if (listener instanceof StoreListener) {
types |= 2 << LifecycleEvent.BEFORE_STORE;
types |= 2 << LifecycleEvent.AFTER_STORE;
}
if (listener instanceof DetachListener) {
types |= 2 << LifecycleEvent.BEFORE_DETACH;
types |= 2 << LifecycleEvent.AFTER_DETACH;
}
if (listener instanceof AttachListener) {
types |= 2 << LifecycleEvent.BEFORE_ATTACH;
types |= 2 << LifecycleEvent.AFTER_ATTACH;
}
return types;
}
}
}