org.apache.flink.table.planner.plan.nodes.exec.ExecNodeGraphGenerator Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of flink-table-planner-blink_2.11 Show documentation

This module bridges Table/SQL API and runtime. It contains all resources that are required during pre-flight and runtime phase. The content of this module is work-in-progress. It will replace flink-table-planner once it is stable. See FLINK-11439 and FLIP-32 for more details.

There is a newer version: 1.13.6

Show newest version

/*
 * 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.table.planner.plan.nodes.exec;

import org.apache.flink.table.api.TableException;
import org.apache.flink.table.planner.plan.nodes.common.CommonIntermediateTableScan;
import org.apache.flink.table.planner.plan.nodes.physical.FlinkPhysicalRel;

import org.apache.calcite.rel.RelNode;

import java.util.ArrayList;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Map;

/**
 * A generator that generates a {@link ExecNode} graph from a graph of {@link FlinkPhysicalRel}s.
 *
 * This traverses the tree of {@link FlinkPhysicalRel} starting from the sinks. At each rel we
 * recursively transform the inputs, then create a {@link ExecNode}. Each rel will be visited only
 * once, that means a rel will only generate one ExecNode instance.
 *
 * Exchange and Union will create a actual node in the {@link ExecNode} graph as the first step,
 * once all ExecNodes' implementation are separated from physical rel, we will use {@link
 * InputProperty} to replace them.
 */
public class ExecNodeGraphGenerator {

    private final Map> visitedRels;

    public ExecNodeGraphGenerator() {
        this.visitedRels = new IdentityHashMap<>();
    }

    public ExecNodeGraph generate(List relNodes) {
        List> rootNodes = new ArrayList<>(relNodes.size());
        for (FlinkPhysicalRel relNode : relNodes) {
            rootNodes.add(generate(relNode));
        }
        return new ExecNodeGraph(rootNodes);
    }

    private ExecNode generate(FlinkPhysicalRel rel) {
        ExecNode execNode = visitedRels.get(rel);
        if (execNode != null) {
            return execNode;
        }

        if (rel instanceof CommonIntermediateTableScan) {
            throw new TableException("Intermediate RelNode can't be converted to ExecNode.");
        }

        List> inputNodes = new ArrayList<>();
        for (RelNode input : rel.getInputs()) {
            inputNodes.add(generate((FlinkPhysicalRel) input));
        }

        execNode = rel.translateToExecNode();
        // connects the input nodes
        List inputEdges = new ArrayList<>(inputNodes.size());
        for (ExecNode inputNode : inputNodes) {
            inputEdges.add(ExecEdge.builder().source(inputNode).target(execNode).build());
        }
        execNode.setInputEdges(inputEdges);

        visitedRels.put(rel, execNode);
        return execNode;
    }
}