| /* |
| 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.edgent.window; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.edgent.function.BiConsumer; |
| import org.apache.edgent.function.BiFunction; |
| import org.apache.edgent.function.Consumer; |
| import org.apache.edgent.function.Supplier; |
| |
| /** |
| * Common window policies. |
| * |
| */ |
| public class Policies { |
| |
| /** |
| * A policy which schedules a future partition eviction if the partition is empty. |
| * This can be used as a contents policy that is scheduling the eviction of |
| * the tuple just about to be inserted. |
| * @param <T> Tuple Type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @param time The time span in which tuple are permitted in the partition. |
| * @param unit The units of time. |
| * @return The time-based contents policy. |
| */ |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> scheduleEvictIfEmpty(long time, TimeUnit unit){ |
| return (partition, tuple) -> { |
| if(partition.getContents().isEmpty()){ |
| ScheduledExecutorService ses = partition.getWindow().getScheduledExecutorService(); |
| ses.schedule(() -> partition.evict(), time, unit); |
| } |
| }; |
| } |
| |
| /** |
| * A policy which schedules a future partition eviction on the first insert. |
| * This can be used as a contents policy that schedules the eviction of tuples |
| * as a batch. |
| * @param <T> Tuple Type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @param time The time span in which tuple are permitted in the partition. |
| * @param unit The units of time. |
| * @return The time-based contents policy. |
| */ |
| @SuppressWarnings("serial") |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> scheduleEvictOnFirstInsert(long time, TimeUnit unit){ |
| |
| // Can't use lambda since state is required |
| return new BiConsumer<Partition<T,K,L>, T>() { |
| private Set<Partition<T,K,L>> initialized_partitions = Collections.synchronizedSet(new HashSet<>()); |
| @Override |
| public void accept(Partition<T, K, L> partition, T tuple) { |
| if(!initialized_partitions.contains(partition)){ |
| initialized_partitions.add(partition); |
| ScheduledExecutorService ses = partition.getWindow().getScheduledExecutorService(); |
| ses.schedule(() -> partition.evict(), time, unit); |
| } |
| } |
| }; |
| } |
| |
| /** |
| * An eviction policy which evicts all tuples that are older than a specified time. |
| * If any tuples remain in the partition, it schedules their eviction after |
| * an appropriate interval. |
| * @param <T> Tuple Type |
| * @param <K> Key type |
| * @param time The timespan in which tuple are permitted in the partition. |
| * @param unit The units of time. |
| * @return The time-based eviction policy. |
| */ |
| public static <T, K> Consumer<Partition<T, K, InsertionTimeList<T>> > evictOlderWithProcess(long time, TimeUnit unit){ |
| |
| long timeMs = TimeUnit.MILLISECONDS.convert(time, unit); |
| |
| return (partition) -> { |
| ScheduledExecutorService ses = partition.getWindow().getScheduledExecutorService(); |
| InsertionTimeList<T> tuples = partition.getContents(); |
| long evictTime = System.currentTimeMillis() - timeMs; |
| |
| tuples.evictOlderThan(evictTime); |
| |
| partition.process(); |
| |
| if(!tuples.isEmpty()){ |
| ses.schedule(() -> partition.evict(), tuples.nextEvictDelay(timeMs), TimeUnit.MILLISECONDS); |
| } |
| }; |
| } |
| |
| /** |
| * An eviction policy which processes the window, evicts all tuples, and |
| * schedules the next eviction after the appropriate interval. |
| * @param <T> Tuple Type |
| * @param <K> Key type |
| * @param time The timespan in which tuple are permitted in the partition. |
| * @param unit The units of time. |
| * @return The time-based eviction policy. |
| */ |
| public static <T, K> Consumer<Partition<T, K, List<T>> > evictAllAndScheduleEvictWithProcess(long time, TimeUnit unit){ |
| |
| long timeMs = TimeUnit.MILLISECONDS.convert(time, unit); |
| return (partition) -> { |
| ScheduledExecutorService ses = partition.getWindow().getScheduledExecutorService(); |
| List<T> tuples = partition.getContents(); |
| |
| partition.process(); |
| tuples.clear(); |
| |
| ses.schedule(() -> partition.evict(), timeMs, TimeUnit.MILLISECONDS); |
| }; |
| } |
| |
| |
| /** |
| * Returns an insertion policy that indicates the tuple |
| * is to be inserted into the partition. |
| * |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * |
| * @return An insertion policy that always inserts. |
| */ |
| public static <T, K, L extends List<T>> BiFunction<Partition<T, K, L>, T, Boolean> alwaysInsert(){ |
| return (partition, tuple) -> true; |
| } |
| |
| /** |
| * Returns a count-based contents policy. |
| * If, when called, the number of tuples in the partition is |
| * greater than equal to {@code count} then {@code partition.evict()} |
| * is called. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @param count the count |
| * @return A count-based contents policy. |
| */ |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> countContentsPolicy(final int count){ |
| return (partition, tuple) -> { |
| if (partition.getContents().size() >= count) |
| partition.evict(); |
| }; |
| } |
| |
| /** |
| * Returns a Consumer representing an evict determiner that evict all tuples |
| * from the window. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @return An evict determiner that evicts all tuples. |
| */ |
| public static <T, K, L extends List<T>> Consumer<Partition<T, K, L> > evictAll(){ |
| return partition -> partition.getContents().clear(); |
| } |
| |
| /** |
| * Returns an evict determiner that evicts the oldest tuple. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @return A evict determiner that evicts the oldest tuple. |
| */ |
| public static <T, K, L extends List<T>> Consumer<Partition<T, K, L> > evictOldest(){ |
| return partition -> partition.getContents().remove(0); |
| } |
| |
| /** |
| * Returns a trigger policy that triggers |
| * processing on every insert. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @return A trigger policy that triggers processing on every insert. |
| */ |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> processOnInsert(){ |
| return (partition, tuple) -> partition.process(); |
| } |
| |
| /** |
| * Returns a trigger policy that triggers when the size of a partition |
| * equals or exceeds a value, and then evicts its contents. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @param size partition size |
| * @return A trigger policy that triggers processing when the size of |
| * the partition equals or exceets a value. |
| */ |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> processWhenFullAndEvict(final int size){ |
| return (partition, tuple) -> { |
| if(partition.getContents().size() >= size){ |
| partition.process(); |
| partition.evict(); |
| } |
| }; |
| } |
| |
| /** |
| * A {@link BiConsumer} policy which does nothing. |
| * @param <T> Tuple type |
| * @param <K> Key type |
| * @param <L> List type for the partition contents. |
| * @return A policy which does nothing. |
| */ |
| public static <T, K, L extends List<T>> BiConsumer<Partition<T, K, L>, T> doNothing(){ |
| return (partition, key) -> {}; |
| } |
| |
| public static <T> Supplier<InsertionTimeList<T>> insertionTimeList() { |
| return () -> new InsertionTimeList<>(); |
| } |
| } |