Github user dawidwys commented on a diff in the pull request:
https://github.com/apache/flink/pull/4145#discussion_r122974349
--- Diff:
flink-libraries/flink-cep/src/main/java/org/apache/flink/cep/nfa/ConditionRegistry.java
---
@@ -0,0 +1,135 @@
+/*
+ * 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.cep.nfa;
+
+import org.apache.flink.api.common.functions.RuntimeContext;
+import org.apache.flink.api.common.functions.util.FunctionUtils;
+import org.apache.flink.cep.pattern.conditions.IterativeCondition;
+import org.apache.flink.configuration.Configuration;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * The {@link ConditionRegistry} is a registry to manage the mapping from
a {@link StateTransition}
+ * to the {@link IterativeCondition}. A {@link StateTransition} is unique
in a {@link NFA}, that's
+ * why we use {@link StateTransition} as the key.
+ */
+public class ConditionRegistry implements Serializable {
+ private static final long serialVersionUID = -4130291010425184830L;
+
+ private final Map<TransitionInfo, IterativeCondition<?>>
registeredConditions;
+
+ private final TransitionInfo reuse = new TransitionInfo();
+
+ /**
+ * Creates a new condition registry.
+ */
+ public ConditionRegistry() {
+ this.registeredConditions = new HashMap<>();
--- End diff --
Personally prefer initializing it in the static part of the class. It is
easier to navigate. Anyway it is already done this way for `TransitionInfo
reuse`.
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