Github user sihuazhou commented on a diff in the pull request:
https://github.com/apache/flink/pull/6196#discussion_r198014021
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/ttl/TtlStateFactory.java
---
@@ -0,0 +1,207 @@
+/*
+ * 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.state.AggregatingStateDescriptor;
+import org.apache.flink.api.common.state.FoldingStateDescriptor;
+import org.apache.flink.api.common.state.ListStateDescriptor;
+import org.apache.flink.api.common.state.MapStateDescriptor;
+import org.apache.flink.api.common.state.ReducingStateDescriptor;
+import org.apache.flink.api.common.state.State;
+import org.apache.flink.api.common.state.StateDescriptor;
+import org.apache.flink.api.common.state.ValueStateDescriptor;
+import org.apache.flink.api.common.typeutils.CompositeSerializer;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.api.common.typeutils.base.LongSerializer;
+import org.apache.flink.api.java.tuple.Tuple2;
+import org.apache.flink.runtime.state.KeyedStateFactory;
+import org.apache.flink.util.FlinkRuntimeException;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * This state factory wraps state objects, produced by backends, with TTL
logic.
+ */
+public class TtlStateFactory {
+ public static <N, SV, S extends State, IS extends S> IS
createStateAndWrapWithTtlIfEnabled(
+ TypeSerializer<N> namespaceSerializer,
+ StateDescriptor<S, SV> stateDesc,
+ KeyedStateFactory originalStateFactory,
+ TtlConfig ttlConfig,
+ TtlTimeProvider timeProvider) throws Exception {
+ return ttlConfig.getTtlUpdateType() == TtlUpdateType.Disabled ?
+ originalStateFactory.createState(namespaceSerializer,
stateDesc) :
+ new TtlStateFactory(originalStateFactory, ttlConfig,
timeProvider)
+ .createState(namespaceSerializer, stateDesc);
+ }
+
+ private final Map<Class<? extends StateDescriptor>, StateFactory>
stateFactories;
--- End diff --
I see, but this looks a bit weird, it looks like that the `stateFactories`
is only used for looking up the corresponding state factory for the
`stateDesc`, and we need to firstly create it every time when calling the
`createStateAndWrapWithTtlIfEnabled()`, the flow of the
`createStateAndWrapWithTtlIfEnabled()` looks like:
- create a map of `state factory` (stateFactories).
- use the stateFactories to look up the corresponding state factory for the
`stateDesc`.
- ...
In that case, maybe use the `switch case` to find the corresponding state
factory is better, at lest we don't need to firstly create a map of `state
factory` for every call this way. What do you think?
---
