com.twitter.heron.api.windowing.triggers.TimeTriggerPolicy Maven / Gradle / Ivy
// Copyright 2017 Twitter. 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.
/**
* 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 com.twitter.heron.api.windowing.triggers;
import java.io.Serializable;
import java.time.Duration;
import com.twitter.heron.api.Config;
import com.twitter.heron.api.windowing.DefaultEvictionContext;
import com.twitter.heron.api.windowing.Event;
import com.twitter.heron.api.windowing.TriggerHandler;
/**
* Invokes {@link TriggerHandler#onTrigger()} after the duration.
*/
public class TimeTriggerPolicy extends AbstractBaseTriggerPolicy {
private long duration;
public TimeTriggerPolicy(long millis) {
super();
this.duration = millis;
}
@Override
public void track(Event event) {
}
@Override
public void reset() {
}
@Override
public void start() {
super.start();
Config.registerTopologyTimerEvents(this.topoConf, "TimeTriggerPolicyTimer",
Duration.ofMillis(this.duration), () -> triggerTask());
}
@Override
public void shutdown() {
}
@Override
public String toString() {
return "TimeTriggerPolicy{" + "duration=" + duration + '}';
}
private void triggerTask() {
// do not process current timestamp since tuples might arrive while the trigger is executing
long now = System.currentTimeMillis() - 1;
/*
* set the current timestamp as the reference time for the eviction policy
* to evict the events
*/
evictionPolicy.setContext(new DefaultEvictionContext(now, null, null, duration));
handler.onTrigger();
}
@Override
public Void getState() {
return null;
}
@Override
public void restoreState(Void state) {
}
}