/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.map.impl;
import com.hazelcast.core.EntryEventType;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.nio.serialization.IdentifiedDataSerializable;
import com.hazelcast.spi.EventFilter;
import com.hazelcast.spi.impl.eventservice.impl.TrueEventFilter;
import java.io.IOException;
import static com.hazelcast.map.impl.MapListenerFlagOperator.SET_ALL_LISTENER_FLAGS;
/**
* Event filter matching events of specified types. This filter also contains an another filter but it does not
* involve it when evaluating if the event matches.
* Prevents sending of not requested events to a {@link com.hazelcast.map.listener.MapListener MapListener}
* by filtering events according the implemented {@link com.hazelcast.map.listener.MapListener MapListener} sub-interfaces.
* <p/>
* Specifically, for example, if a listener is registered via an implementation like this:
* <p/>
* {@code}
* public class MyMapListener implements EntryAddedListener, EntryRemovedListener {
* ...
* }
* {@code}
* <p/>
* That listener will only be notified for {@link EntryEventType#ADDED} and {@link EntryEventType#REMOVED} events.
* Other events, like {@link EntryEventType#EVICTED} or {@link EntryEventType#EXPIRED}, will not be sent over wire.
* This may help to reduce load on eventing system and network.
*
* @see MapListenerFlagOperator#setAndGetListenerFlags(ListenerAdapter)
* @see com.hazelcast.map.listener.MapListener
* @since 3.6
*/
public class EventListenerFilter implements EventFilter, IdentifiedDataSerializable {
/**
* Flags of implemented listeners.
*/
private int listenerFlags;
private EventFilter eventFilter;
public EventListenerFilter() {
this(SET_ALL_LISTENER_FLAGS, TrueEventFilter.INSTANCE);
}
public EventListenerFilter(int listenerFlags, EventFilter eventFilter) {
this.listenerFlags = listenerFlags;
this.eventFilter = eventFilter == null ? TrueEventFilter.INSTANCE : eventFilter;
}
@Override
public void writeData(ObjectDataOutput out) throws IOException {
out.writeObject(eventFilter);
out.writeInt(listenerFlags);
}
@Override
public void readData(ObjectDataInput in) throws IOException {
eventFilter = in.readObject();
listenerFlags = in.readInt();
}
@Override
public boolean eval(Object object) {
Integer eventType = (Integer) object;
return (listenerFlags & eventType) != 0;
}
public EventFilter getEventFilter() {
return eventFilter;
}
@Override
public String toString() {
return "EventListenerFilter{"
+ "listenerFlags=" + listenerFlags
+ ", eventFilter=" + eventFilter
+ '}';
}
@Override
public int getFactoryId() {
return MapDataSerializerHook.F_ID;
}
@Override
public int getId() {
return MapDataSerializerHook.EVENT_LISTENER_FILTER;
}
}