Github user StefanRRichter commented on a diff in the pull request:
https://github.com/apache/flink/pull/6186#discussion_r197458219
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/ttl/AbstractTtlDecorator.java
---
@@ -0,0 +1,99 @@
+/*
+ * 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.util.Preconditions;
+import org.apache.flink.util.function.SupplierWithException;
+import org.apache.flink.util.function.ThrowingConsumer;
+import org.apache.flink.util.function.ThrowingRunnable;
+
+/**
+ * Base class for TTL logic wrappers.
+ *
+ * @param <T> Type of originally wrapped object
+ */
+abstract class AbstractTtlDecorator<T> {
+ final T original;
+ final TtlConfig config;
+ final TtlTimeProvider timeProvider;
+ final boolean updateTsOnRead;
+ final boolean returnExpired;
--- End diff --
A bit more field comments might be good, especially about the exact
meanings of those boolean flags. For example, it is not super obvious what
`returnExpired` means for the code.
---
