Github user StefanRRichter commented on a diff in the pull request:
https://github.com/apache/flink/pull/6186#discussion_r197502165
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/ttl/TtlFoldFunction.java
---
@@ -0,0 +1,43 @@
+/*
+ * 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.functions.FoldFunction;
+
+/**
+ * This class wraps folding function with TTL logic.
+ *
+ * @param <T> Type of the values folded into the state
+ * @param <ACC> Type of the value in the state
+ *
+ * @deprecated use {@link TtlAggregateFunction} instead
+ */
+@Deprecated
+class TtlFoldFunction<T, ACC>
+ extends AbstractTtlDecorator<FoldFunction<T, ACC>>
+ implements FoldFunction<T, TtlValue<ACC>> {
+ TtlFoldFunction(FoldFunction<T, ACC> original, TtlConfig config,
TtlTimeProvider timeProvider) {
+ super(original, config, timeProvider);
+ }
+
+ @Override
+ public TtlValue<ACC> fold(TtlValue<ACC> accumulator, T value) throws
Exception {
+ return wrapWithTs(original.fold(getUnexpried(accumulator),
value));
--- End diff --
I this is true, that is a valuable case to be tested for all the appending
states that they work correctly.
---
