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ASF GitHub Bot commented on FLINK-9514: --------------------------------------- Github user Aitozi commented on a diff in the pull request: https://github.com/apache/flink/pull/6186#discussion_r201895445 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/state/ttl/TtlListState.java --- @@ -0,0 +1,171 @@ +/* + * 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.runtime.state.ttl; + +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.runtime.state.internal.InternalListState; +import org.apache.flink.util.Preconditions; + +import java.util.Collection; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.stream.Collectors; +import java.util.stream.StreamSupport; + +/** + * This class wraps list state with TTL logic. + * + * @param <K> The type of key the state is associated to + * @param <N> The type of the namespace + * @param <T> Type of the user entry value of state with TTL + */ +class TtlListState<K, N, T> extends + AbstractTtlState<K, N, List<T>, List<TtlValue<T>>, InternalListState<K, N, TtlValue<T>>> + implements InternalListState<K, N, T> { + TtlListState( + InternalListState<K, N, TtlValue<T>> originalState, + TtlConfig config, + TtlTimeProvider timeProvider, + TypeSerializer<List<T>> valueSerializer) { + super(originalState, config, timeProvider, valueSerializer); + } + + @Override + public void update(List<T> values) throws Exception { + updateInternal(values); + } + + @Override + public void addAll(List<T> values) throws Exception { + Preconditions.checkNotNull(values, "List of values to add cannot be null."); + original.addAll(withTs(values)); + } + + @Override + public Iterable<T> get() throws Exception { + Iterable<TtlValue<T>> ttlValue = original.get(); + ttlValue = ttlValue == null ? Collections.emptyList() : ttlValue; + if (updateTsOnRead) { + List<TtlValue<T>> collected = collect(ttlValue); + ttlValue = collected; + updateTs(collected); + } + final Iterable<TtlValue<T>> finalResult = ttlValue; + return () -> new IteratorWithCleanup(finalResult.iterator()); + } + + private void updateTs(List<TtlValue<T>> ttlValue) throws Exception { + List<TtlValue<T>> unexpiredWithUpdatedTs = ttlValue.stream() + .filter(v -> !expired(v)) + .map(this::rewrapWithNewTs) + .collect(Collectors.toList()); + if (!unexpiredWithUpdatedTs.isEmpty()) { + original.update(unexpiredWithUpdatedTs); + } + } + + @Override + public void add(T value) throws Exception { + Preconditions.checkNotNull(value, "You cannot add null to a ListState."); + original.add(wrapWithTs(value)); + } + + @Override + public void clear() { + original.clear(); + } + + @Override + public void mergeNamespaces(N target, Collection<N> sources) throws Exception { + original.mergeNamespaces(target, sources); + } + + @Override + public List<T> getInternal() throws Exception { + return collect(get()); + } + + private <E> List<E> collect(Iterable<E> iterable) { --- End diff -- Hi @azagrebin , little doubt that you say the > return Iterable and avoid querying backend if not needed But when deal with the ListState the `original.get()` has already query the original `Iterable` from RocksDB doesn't it ? Is this way just lazy query the iterable element in memory? > Create wrapper with TTL logic for value state > --------------------------------------------- > > Key: FLINK-9514 > URL: https://issues.apache.org/jira/browse/FLINK-9514 > Project: Flink > Issue Type: Sub-task > Components: State Backends, Checkpointing > Affects Versions: 1.6.0 > Reporter: Andrey Zagrebin > Assignee: Andrey Zagrebin > Priority: Major > Labels: pull-request-available > Fix For: 1.6.0 > > > TTL state decorator uses original state with packed TTL and add TTL logic > using time provider: > {code:java} > TtlValueState<V> implements ValueState<V> { > ValueState<TtlValue<V>> underlyingState; > InternalTimeService timeProvider; > V value() { > TtlValue<V> valueWithTtl = underlyingState.get(); > // ttl logic here (e.g. update timestamp) > return valueWithTtl.getValue(); > } > void update() { ... underlyingState.update(valueWithTtl) ... } > } > {code} > TTL decorators are apply to state produced by normal state binder in its TTL > wrapper from FLINK-9513 -- This message was sent by Atlassian JIRA (v7.6.3#76005)