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/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or .
*/
package org.hibernate.event.service.internal;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Supplier;
import org.hibernate.event.service.spi.DuplicationStrategy;
import org.hibernate.event.service.spi.EventActionWithParameter;
import org.hibernate.event.service.spi.EventListenerGroup;
import org.hibernate.event.service.spi.EventListenerRegistrationException;
import org.hibernate.event.service.spi.JpaBootstrapSensitive;
import org.hibernate.event.spi.EventType;
import org.hibernate.jpa.event.spi.CallbackRegistryConsumer;
/**
* @author Steve Ebersole
* @author Sanne Grinovero
*/
class EventListenerGroupImpl implements EventListenerGroup {
private EventType eventType;
private final EventListenerRegistryImpl listenerRegistry;
private final Set duplicationStrategies = new LinkedHashSet<>();
// Performance: make sure iteration on this type is efficient; in particular we do not want to allocate iterators,
// not having to capture state in lambdas.
// So we keep the listeners in both a List (for convenience) and in an array (for iteration). Make sure
// their content stays in synch!
private T[] listeners = null;
//Update both fields when making changes!
private List listenersAsList;
public EventListenerGroupImpl(EventType eventType, EventListenerRegistryImpl listenerRegistry) {
this.eventType = eventType;
this.listenerRegistry = listenerRegistry;
duplicationStrategies.add(
// At minimum make sure we do not register the same exact listener class multiple times.
new DuplicationStrategy() {
@Override
public boolean areMatch(Object listener, Object original) {
return listener.getClass().equals( original.getClass() );
}
@Override
public Action getAction() {
return Action.ERROR;
}
}
);
}
@Override
public EventType getEventType() {
return eventType;
}
@Override
public boolean isEmpty() {
return count() <= 0;
}
@Override
public int count() {
final T[] ls = listeners;
return ls == null ? 0 : ls.length;
}
@Override
public void clear() {
if ( duplicationStrategies != null ) {
duplicationStrategies.clear();
}
listeners = null;
listenersAsList = null;
}
@Override
public final void fireLazyEventOnEachListener(final Supplier eventSupplier, final BiConsumer actionOnEvent) {
final T[] ls = listeners;
if ( ls != null && ls.length != 0 ) {
final U event = eventSupplier.get();
for ( T listener : ls ) {
actionOnEvent.accept( listener, event );
}
}
}
@Override
public final void fireEventOnEachListener(final U event, final BiConsumer actionOnEvent) {
final T[] ls = listeners;
if ( ls != null ) {
for ( T listener : ls ) {
actionOnEvent.accept( listener, event );
}
}
}
@Override
public void fireEventOnEachListener(final U event, final X parameter, final EventActionWithParameter actionOnEvent) {
final T[] ls = listeners;
if ( ls != null ) {
for ( T listener : ls ) {
actionOnEvent.applyEventToListener( listener, event, parameter );
}
}
}
@Override
public void addDuplicationStrategy(DuplicationStrategy strategy) {
duplicationStrategies.add( strategy );
}
/**
* Implementation note: should be final for performance reasons.
* @deprecated this is not the most efficient way for iterating the event listeners.
* See {@link #fireEventOnEachListener(Object, BiConsumer)} and co. for better alternatives.
*/
@Override
@Deprecated
public final Iterable listeners() {
final List ls = listenersAsList;
return ls == null ? Collections.EMPTY_LIST : ls;
}
@Override
@SafeVarargs
public final void appendListeners(T... listeners) {
internalAppendListeners( listeners );
checkForArrayRefresh();
}
private void checkForArrayRefresh() {
final List list = listenersAsList;
if ( this.listeners == null ) {
T[] a = (T[]) Array.newInstance( eventType.baseListenerInterface(), list.size() );
listeners = list.toArray( a );
}
}
private void internalAppendListeners(T[] listeners) {
for ( T listener : listeners ) {
internalAppendListener( listener );
}
}
@Override
public void appendListener(T listener) {
internalAppendListener( listener );
checkForArrayRefresh();
}
private void internalAppendListener(T listener) {
if ( listenerShouldGetAdded( listener ) ) {
internalAppend( listener );
}
}
@Override
@SafeVarargs
public final void prependListeners(T... listeners) {
internalPrependListeners( listeners );
checkForArrayRefresh();
}
private void internalPrependListeners(T[] listeners) {
for ( T listener : listeners ) {
internalPreprendListener( listener );
}
}
@Override
public void prependListener(T listener) {
internalPreprendListener( listener );
checkForArrayRefresh();
}
private void internalPreprendListener(T listener) {
if ( listenerShouldGetAdded( listener ) ) {
internalPrepend( listener );
}
}
private boolean listenerShouldGetAdded(T listener) {
final List ts = listenersAsList;
if ( ts == null ) {
listenersAsList = new ArrayList<>();
return true;
// no need to do de-dup checks
}
boolean doAdd = true;
strategy_loop: for ( DuplicationStrategy strategy : duplicationStrategies ) {
final ListIterator itr = ts.listIterator();
while ( itr.hasNext() ) {
final T existingListener = itr.next();
if ( strategy.areMatch( listener, existingListener ) ) {
switch ( strategy.getAction() ) {
// todo : add debug logging of what happens here...
case ERROR: {
throw new EventListenerRegistrationException( "Duplicate event listener found" );
}
case KEEP_ORIGINAL: {
doAdd = false;
break strategy_loop;
}
case REPLACE_ORIGINAL: {
checkAgainstBaseInterface( listener );
performInjections( listener );
itr.set( listener );
doAdd = false;
break strategy_loop;
}
}
}
}
}
return doAdd;
}
private void internalPrepend(T listener) {
checkAgainstBaseInterface( listener );
performInjections( listener );
listenersAsList.add( 0, listener );
listeners = null; //Marks it for refreshing
}
private void performInjections(T listener) {
if ( CallbackRegistryConsumer.class.isInstance( listener ) ) {
( (CallbackRegistryConsumer) listener ).injectCallbackRegistry( listenerRegistry.getCallbackRegistry() );
}
if ( JpaBootstrapSensitive.class.isInstance( listener ) ) {
( (JpaBootstrapSensitive) listener ).wasJpaBootstrap(
listenerRegistry.getSessionFactory().getSessionFactoryOptions().isJpaBootstrap()
);
}
}
private void checkAgainstBaseInterface(T listener) {
if ( !eventType.baseListenerInterface().isInstance( listener ) ) {
throw new EventListenerRegistrationException(
"Listener did not implement expected interface [" + eventType.baseListenerInterface().getName() + "]"
);
}
}
private void internalAppend(T listener) {
checkAgainstBaseInterface( listener );
performInjections( listener );
listenersAsList.add( listener );
listeners = null; //Marks it for refreshing
}
}