[FLINK-20437][table-planner-blink] Port ExecNode to Java

flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/planner/plan/nodes/exec/ExecNode.java

@@ -0,0 +1,74 @@
+/*
+ * 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:https://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.table.planner.plan.nodes.exec;
+
+import org.apache.flink.api.dag.Transformation;
+import org.apache.flink.table.delegation.Planner;
+import org.apache.flink.table.planner.plan.nodes.physical.FlinkPhysicalRel;
+
+import java.util.List;
+
+/**
+ * The representation of execution information for a {@link FlinkPhysicalRel}.
+ *
+ * @param <T> The type of the elements that result from this node.
+ */
+public interface ExecNode<T> {
+
+ /**
+ * Returns a list of this node's input nodes.
+ * If there are no inputs, returns an empty list, not null.
+ *
+ * @return List of this node's input nodes
+ */
+ List<ExecNode<?>> getInputNodes();
+
+ /**
+ * Returns a list of this node's input edges.
+ * If there are no inputs, returns an empty list, not null.
+ *
+ * @return List of this node's input edges
+ */
+ List<ExecEdge> getInputEdges();
+
+ /**
+ * Replaces the <code>ordinalInParent</code><sup>th</sup> input.
+ * You must override this method if you override {@link #getInputNodes}.
+ *
+ * @param ordinalInParent Position of the child input, 0 is the first
+ * @param newInputNode New node that should be put at position ordinalInParent
+ */
+ void replaceInputNode(int ordinalInParent, ExecNode<?> newInputNode);
+
+ /**
+ * Translates this node into a Flink operator.
+ *
+ * <p>NOTE: This method should return same translate result if called multiple times.
+ *
+ * @param planner The {@link Planner} of the translated Table.
+ */
+ Transformation<T> translateToPlan(Planner planner);
+
+ /**
+ * Accepts a visit from a {@link ExecNodeVisitor}.
+ *
+ * @param visitor ExecNodeVisitor
+ */
+ void accept(ExecNodeVisitor visitor);
+}