/*
* 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.jackrabbit.jcr2spi.observation;
import java.util.Iterator;
import java.util.NoSuchElementException;
import javax.jcr.observation.Event;
import javax.jcr.observation.EventIterator;
import org.apache.jackrabbit.spi.EventFilter;
import org.apache.jackrabbit.spi.IdFactory;
import org.apache.jackrabbit.spi.commons.conversion.NamePathResolver;
/**
* Implements an event iterator that converts SPI events into JCR events and
* filters out the ones that are not accepted by an {@link EventFilter}.
*/
class FilteredEventIterator implements EventIterator {
/**
* The actual {@link org.apache.jackrabbit.spi.Event}s fired by the repository service
* (unfiltered).
*/
protected final Iterator<org.apache.jackrabbit.spi.Event> actualEvents;
/**
* For filtering the {@link javax.jcr.observation.Event}s.
*/
private final EventFilter filter;
/**
* If <code>true</code> these events are local.
*/
private final boolean isLocal;
/**
* The namespace resolver of the session that created this event iterator.
*/
private final NamePathResolver resolver;
/**
* The IdFactory
*/
private final IdFactory idFactory;
/**
* The next {@link javax.jcr.observation.Event} in this iterator
*/
private Event next;
/**
* Current position
*/
private long pos = 0;
/**
* Creates a new <code>FilteredEventIterator</code>.
*
* @param events the {@link org.apache.jackrabbit.spi.Event}s as an
* iterator.
* @param isLocal whether the events were caused by the local session.
* @param filter only event that pass the filter will be dispatched to
* the event listener.
* @param resolver the name path resolver.
* @param idFactory the id factory.
*/
public FilteredEventIterator(Iterator<org.apache.jackrabbit.spi.Event> events,
boolean isLocal,
EventFilter filter,
NamePathResolver resolver,
IdFactory idFactory) {
this.actualEvents = events;
this.filter = filter;
this.isLocal = isLocal;
this.resolver = resolver;
this.idFactory = idFactory;
fetchNext();
}
/**
* {@inheritDoc}
*/
public Object next() {
if (next == null) {
throw new NoSuchElementException();
}
Event e = next;
fetchNext();
pos++;
return e;
}
/**
* {@inheritDoc}
*/
public Event nextEvent() {
return (Event) next();
}
/**
* {@inheritDoc}
*/
public void skip(long skipNum) {
while (skipNum-- > 0) {
next();
}
}
/**
* Always returns <code>-1</code>.
*
* @return <code>-1</code>.
*/
public long getSize() {
return -1;
}
/**
* {@inheritDoc}
*/
public long getPosition() {
return pos;
}
/**
* This method is not supported.
* Always throws a <code>UnsupportedOperationException</code>.
*/
public void remove() {
throw new UnsupportedOperationException("EventIterator.remove()");
}
/**
* Returns <tt>true</tt> if the iteration has more elements. (In other
* words, returns <tt>true</tt> if <tt>next</tt> would return an element
* rather than throwing an exception.)
*
* @return <tt>true</tt> if the iterator has more elements.
*/
public boolean hasNext() {
return (next != null);
}
/**
* Fetches the next Event from the collection of events
* passed in the constructor of <code>FilteredEventIterator</code>
* that is allowed by the {@link EventFilter}.
*/
private void fetchNext() {
org.apache.jackrabbit.spi.Event event;
next = null;
while (next == null && actualEvents.hasNext()) {
event = actualEvents.next();
next = filter.accept(event, isLocal) ? new EventImpl(event, resolver, idFactory) : null;
}
}
}