flink-libraries/flink-table/src/main/java/org/apache/flink/table/runtime/window/triggers/ProcessingTime.java - flink - Git at Google

 /*
  * 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.flink.table.runtime.window.triggers;

 import org.apache.flink.api.common.functions.Merger;
 import org.apache.flink.api.common.state.ValueState;
 import org.apache.flink.api.common.state.ValueStateDescriptor;
 import org.apache.flink.api.common.typeinfo.Types;
 import org.apache.flink.table.api.window.Window;

 import java.time.Duration;

 import static org.apache.flink.util.Preconditions.checkArgument;
 import static org.apache.flink.util.Preconditions.checkNotNull;

 /**
  * A {@link Trigger} that reacts to processing-time timers.
  * The behavior can be one of the following:
  * <p><ul>
  *     <li> fire when the processing time passes the end of the window ({@link ProcessingTime#afterEndOfWindow()}),
  *     <li> fire when the processing time advances by a certain interval
  *          after reception of the first element after the last firing for
  *          a given window ({@link ProcessingTime#every(Duration)}).
  * </ul></p>
  * In the first case, the trigger can also specify an <tt>early</tt> trigger.
  * The <tt>early trigger</tt> will be responsible for specifying when the trigger should fire in the period
  * between the beginning of the window and the time when the processing time passes the end of the window.
  */
 public class ProcessingTime {

 	private static final Merger<Long> MERGER = new MinAmongSet();

 	private static final String TO_STRING = "ProcessingTime.afterEndOfWindow()";

 	/**
 	 * Creates a trigger that fires when the processing time passes the end of the window.
 	 */
 	public static <W extends Window> AfterEndOfWindow<W> afterEndOfWindow() {
 		return new AfterEndOfWindow<>();
 	}

 	/**
 	 * Creates a trigger that fires by a certain interval after reception of the first element.
 	 * @param time the certain interval
 	 */
 	public static <W extends Window> AfterFirstElementPeriodic<W> every(Duration time) {
 		return new AfterFirstElementPeriodic<>(time.toMillis());
 	}

 	/**
 	 * Trigger every a given interval, the first trigger time is interval
 	 * after the first element in the pane.
 	 *
 	 * @param <W> type of window
 	 */
 	public static final class AfterFirstElementPeriodic<W extends Window> extends Trigger<W> {

 		private static final long serialVersionUID = -4710472821577125673L;
 		private final long interval;
 		private transient TriggerContext ctx;
 		private transient ValueState<Long> nextFiring;

 		AfterFirstElementPeriodic(long interval) {
 			checkArgument(interval > 0);
 			this.interval = interval;
 		}

 		@Override
 		public void open(TriggerContext ctx) throws Exception {
 			this.ctx = ctx;
 			String descriptorName = "processingTime-every-" + interval;
 			ValueStateDescriptor<Long> nextFiringDescriptor = new ValueStateDescriptor<>(
 				descriptorName,
 				Types.LONG);
 			this.nextFiring = ctx.getValueState(nextFiringDescriptor);
 		}

 		@Override
 		public boolean onElement(Object element, long timestamp, W window) throws Exception {
 			Long timer = nextFiring.value();
 			if (timer == null) {
 				long nextTimer = ctx.getCurrentProcessingTime() + interval;
 				ctx.registerProcessingTimeTimer(nextTimer);
 				nextFiring.update(nextTimer);
 			}
 			return false;
 		}

 		@Override
 		public boolean onProcessingTime(long time, W window) throws Exception {
 			Long timer = nextFiring.value();
 			if (timer != null && timer == time) {
 				long newTimer = time + interval;
 				ctx.registerProcessingTimeTimer(newTimer);
 				nextFiring.update(newTimer);
 				return true;
 			} else {
 				return false;
 			}
 		}

 		@Override
 		public boolean onEventTime(long time, W window) throws Exception {
 			return false;
 		}

 		@Override
 		public boolean canMerge() {
 			return true;
 		}

 		@Override
 		public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
 			Long nextTimer = mergeContext.mergeValueState(nextFiring, MERGER);
 			if (nextTimer != null) {
 				ctx.registerProcessingTimeTimer(nextTimer);
 			}
 		}

 		@Override
 		public void clear(W window) throws Exception {
 			Long timer = nextFiring.value();
 			if (timer != null) {
 				ctx.deleteProcessingTimeTimer(timer);
 				nextFiring.clear();
 			}
 		}

 		@Override
 		public String toString() {
 			return "ProcessingTime.every(" + interval + ")";
 		}
 	}

 	/**
 	 * A {@link Trigger} that fires once the current system time passes the end of the window
 	 * to which a pane belongs.
 	 */
 	public static final class AfterEndOfWindow<W extends Window> extends Trigger<W> {
 		private static final long serialVersionUID = 2369815941792574642L;

 		/**
 		 * Creates a new {@code Trigger} like the this, except that it fires repeatedly whenever
 		 * the given {@code Trigger} fires before the processing time has passed the end of the window.
 		 */
 		public AfterEndOfWindowNoLate<W> withEarlyFirings(Trigger<W> earlyFirings) {
 			checkNotNull(earlyFirings);
 			return new AfterEndOfWindowNoLate<>(earlyFirings);
 		}

 		private TriggerContext ctx;

 		@Override
 		public void open(TriggerContext ctx) throws Exception {
 			this.ctx = ctx;
 		}

 		@Override
 		public boolean onElement(Object element, long timestamp, W window) throws Exception {
 			ctx.registerProcessingTimeTimer(window.maxTimestamp());
 			return false;
 		}

 		@Override
 		public boolean onProcessingTime(long time, W window) throws Exception {
 			return time == window.maxTimestamp();
 		}

 		@Override
 		public boolean onEventTime(long time, W window) throws Exception {
 			return false;
 		}

 		@Override
 		public void clear(W window) throws Exception {
 			ctx.deleteProcessingTimeTimer(window.maxTimestamp());
 		}

 		@Override
 		public boolean canMerge() {
 			return true;
 		}

 		@Override
 		public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
 			ctx.registerProcessingTimeTimer(window.maxTimestamp());
 		}

 		@Override
 		public String toString() {
 			return TO_STRING;
 		}
 	}

 	/**
 	 * A composite {@link Trigger} that consist of AfterEndOfWindow and a early trigger.
 	 */
 	public static final class AfterEndOfWindowNoLate<W extends Window> extends Trigger<W> {

 		private static final long serialVersionUID = 2310050856564792734L;

 		// early trigger is always not null
 		private final Trigger<W> earlyTrigger;
 		private TriggerContext ctx;

 		AfterEndOfWindowNoLate(Trigger<W> earlyTrigger) {
 			checkNotNull(earlyTrigger);
 			this.earlyTrigger = earlyTrigger;
 		}

 		@Override
 		public void open(TriggerContext ctx) throws Exception {
 			this.ctx = ctx;
 			earlyTrigger.open(ctx);
 		}

 		@Override
 		public boolean onElement(Object element, long timestamp, W window) throws Exception {
 			ctx.registerProcessingTimeTimer(window.maxTimestamp());
 			return earlyTrigger.onElement(element, timestamp, window);
 		}

 		@Override
 		public boolean onProcessingTime(long time, W window) throws Exception {
 			return time == window.maxTimestamp() || earlyTrigger.onProcessingTime(time, window);
 		}

 		@Override
 		public boolean onEventTime(long time, W window) throws Exception {
 			return earlyTrigger.onEventTime(time, window);
 		}

 		@Override
 		public boolean canMerge() {
 			return earlyTrigger.canMerge();
 		}

 		@Override
 		public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
 			ctx.registerProcessingTimeTimer(window.maxTimestamp());
 			earlyTrigger.onMerge(window, mergeContext);
 		}

 		@Override
 		public void clear(W window) throws Exception {
 			ctx.deleteProcessingTimeTimer(window.maxTimestamp());
 			earlyTrigger.clear(window);
 		}

 		@Override
 		public String toString() {
 			StringBuilder builder = new StringBuilder(TO_STRING);
 			if (earlyTrigger != null) {
 				builder
 					.append(".withEarlyFirings(")
 					.append(earlyTrigger)
 					.append(")");
 			}
 			return builder.toString();
 		}
 	}

 	// ===================================================================================
 	// Utils
 	// ===================================================================================

 	/**
 	 * Upon merging it returns the minimum among the values.
 	 */
 	private static final class MinAmongSet implements Merger<Long> {
 		private static final long serialVersionUID = 1L;

 		@Override
 		public Long merge(Long value1, Long value2) {
 			if (value1 == null || value2 == null) {
 				return value1 == null ? value2 : value1;
 			} else {
 				return Math.min(value1, value2);
 			}
 		}
 	}
 }
	/*
	* 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.flink.table.runtime.window.triggers;

	import org.apache.flink.api.common.functions.Merger;
	import org.apache.flink.api.common.state.ValueState;
	import org.apache.flink.api.common.state.ValueStateDescriptor;
	import org.apache.flink.api.common.typeinfo.Types;
	import org.apache.flink.table.api.window.Window;

	import java.time.Duration;

	import static org.apache.flink.util.Preconditions.checkArgument;
	import static org.apache.flink.util.Preconditions.checkNotNull;

	/**
	* A {@link Trigger} that reacts to processing-time timers.
	* The behavior can be one of the following:
	* <p><ul>
	* <li> fire when the processing time passes the end of the window ({@link ProcessingTime#afterEndOfWindow()}),
	* <li> fire when the processing time advances by a certain interval
	* after reception of the first element after the last firing for
	* a given window ({@link ProcessingTime#every(Duration)}).
	* </ul></p>
	* In the first case, the trigger can also specify an <tt>early</tt> trigger.
	* The <tt>early trigger</tt> will be responsible for specifying when the trigger should fire in the period
	* between the beginning of the window and the time when the processing time passes the end of the window.
	*/
	public class ProcessingTime {

	private static final Merger<Long> MERGER = new MinAmongSet();

	private static final String TO_STRING = "ProcessingTime.afterEndOfWindow()";

	/**
	* Creates a trigger that fires when the processing time passes the end of the window.
	*/
	public static <W extends Window> AfterEndOfWindow<W> afterEndOfWindow() {
	return new AfterEndOfWindow<>();
	}

	/**
	* Creates a trigger that fires by a certain interval after reception of the first element.
	* @param time the certain interval
	*/
	public static <W extends Window> AfterFirstElementPeriodic<W> every(Duration time) {
	return new AfterFirstElementPeriodic<>(time.toMillis());
	}

	/**
	* Trigger every a given interval, the first trigger time is interval
	* after the first element in the pane.
	*
	* @param <W> type of window
	*/
	public static final class AfterFirstElementPeriodic<W extends Window> extends Trigger<W> {

	private static final long serialVersionUID = -4710472821577125673L;
	private final long interval;
	private transient TriggerContext ctx;
	private transient ValueState<Long> nextFiring;

	AfterFirstElementPeriodic(long interval) {
	checkArgument(interval > 0);
	this.interval = interval;
	}

	@Override
	public void open(TriggerContext ctx) throws Exception {
	this.ctx = ctx;
	String descriptorName = "processingTime-every-" + interval;
	ValueStateDescriptor<Long> nextFiringDescriptor = new ValueStateDescriptor<>(
	descriptorName,
	Types.LONG);
	this.nextFiring = ctx.getValueState(nextFiringDescriptor);
	}

	@Override
	public boolean onElement(Object element, long timestamp, W window) throws Exception {
	Long timer = nextFiring.value();
	if (timer == null) {
	long nextTimer = ctx.getCurrentProcessingTime() + interval;
	ctx.registerProcessingTimeTimer(nextTimer);
	nextFiring.update(nextTimer);
	}
	return false;
	}

	@Override
	public boolean onProcessingTime(long time, W window) throws Exception {
	Long timer = nextFiring.value();
	if (timer != null && timer == time) {
	long newTimer = time + interval;
	ctx.registerProcessingTimeTimer(newTimer);
	nextFiring.update(newTimer);
	return true;
	} else {
	return false;
	}
	}

	@Override
	public boolean onEventTime(long time, W window) throws Exception {
	return false;
	}

	@Override
	public boolean canMerge() {
	return true;
	}

	@Override
	public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
	Long nextTimer = mergeContext.mergeValueState(nextFiring, MERGER);
	if (nextTimer != null) {
	ctx.registerProcessingTimeTimer(nextTimer);
	}
	}

	@Override
	public void clear(W window) throws Exception {
	Long timer = nextFiring.value();
	if (timer != null) {
	ctx.deleteProcessingTimeTimer(timer);
	nextFiring.clear();
	}
	}

	@Override
	public String toString() {
	return "ProcessingTime.every(" + interval + ")";
	}
	}

	/**
	* A {@link Trigger} that fires once the current system time passes the end of the window
	* to which a pane belongs.
	*/
	public static final class AfterEndOfWindow<W extends Window> extends Trigger<W> {
	private static final long serialVersionUID = 2369815941792574642L;

	/**
	* Creates a new {@code Trigger} like the this, except that it fires repeatedly whenever
	* the given {@code Trigger} fires before the processing time has passed the end of the window.
	*/
	public AfterEndOfWindowNoLate<W> withEarlyFirings(Trigger<W> earlyFirings) {
	checkNotNull(earlyFirings);
	return new AfterEndOfWindowNoLate<>(earlyFirings);
	}

	private TriggerContext ctx;

	@Override
	public void open(TriggerContext ctx) throws Exception {
	this.ctx = ctx;
	}

	@Override
	public boolean onElement(Object element, long timestamp, W window) throws Exception {
	ctx.registerProcessingTimeTimer(window.maxTimestamp());
	return false;
	}

	@Override
	public boolean onProcessingTime(long time, W window) throws Exception {
	return time == window.maxTimestamp();
	}

	@Override
	public boolean onEventTime(long time, W window) throws Exception {
	return false;
	}

	@Override
	public void clear(W window) throws Exception {
	ctx.deleteProcessingTimeTimer(window.maxTimestamp());
	}

	@Override
	public boolean canMerge() {
	return true;
	}

	@Override
	public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
	ctx.registerProcessingTimeTimer(window.maxTimestamp());
	}

	@Override
	public String toString() {
	return TO_STRING;
	}
	}

	/**
	* A composite {@link Trigger} that consist of AfterEndOfWindow and a early trigger.
	*/
	public static final class AfterEndOfWindowNoLate<W extends Window> extends Trigger<W> {

	private static final long serialVersionUID = 2310050856564792734L;

	// early trigger is always not null
	private final Trigger<W> earlyTrigger;
	private TriggerContext ctx;

	AfterEndOfWindowNoLate(Trigger<W> earlyTrigger) {
	checkNotNull(earlyTrigger);
	this.earlyTrigger = earlyTrigger;
	}

	@Override
	public void open(TriggerContext ctx) throws Exception {
	this.ctx = ctx;
	earlyTrigger.open(ctx);
	}

	@Override
	public boolean onElement(Object element, long timestamp, W window) throws Exception {
	ctx.registerProcessingTimeTimer(window.maxTimestamp());
	return earlyTrigger.onElement(element, timestamp, window);
	}

	@Override
	public boolean onProcessingTime(long time, W window) throws Exception {
	return time == window.maxTimestamp() \|\| earlyTrigger.onProcessingTime(time, window);
	}

	@Override
	public boolean onEventTime(long time, W window) throws Exception {
	return earlyTrigger.onEventTime(time, window);
	}

	@Override
	public boolean canMerge() {
	return earlyTrigger.canMerge();
	}

	@Override
	public void onMerge(W window, OnMergeContext mergeContext) throws Exception {
	ctx.registerProcessingTimeTimer(window.maxTimestamp());
	earlyTrigger.onMerge(window, mergeContext);
	}

	@Override
	public void clear(W window) throws Exception {
	ctx.deleteProcessingTimeTimer(window.maxTimestamp());
	earlyTrigger.clear(window);
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder(TO_STRING);
	if (earlyTrigger != null) {
	builder
	.append(".withEarlyFirings(")
	.append(earlyTrigger)
	.append(")");
	}
	return builder.toString();
	}
	}

	// ===================================================================================
	// Utils
	// ===================================================================================

	/**
	* Upon merging it returns the minimum among the values.
	*/
	private static final class MinAmongSet implements Merger<Long> {
	private static final long serialVersionUID = 1L;

	@Override
	public Long merge(Long value1, Long value2) {
	if (value1 == null \|\| value2 == null) {
	return value1 == null ? value2 : value1;
	} else {
	return Math.min(value1, value2);
	}
	}
	}
	}