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This module contains classes that are required by a task manager for execution of table programs. The content of this module is work-in-progress. It will replace the runtime classes contained in flink-table-planner once it is stable. See FLINK-11439 and FLIP-32 for more details.

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/*
 * 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.runtime.collector;

import org.apache.flink.api.common.functions.AbstractRichFunction;
import org.apache.flink.table.functions.TableFunction;
import org.apache.flink.util.Collector;

/** The basic implementation of collector for {@link TableFunction}. */
public abstract class TableFunctionCollector extends AbstractRichFunction
        implements Collector {

    private static final long serialVersionUID = 1L;

    private Object input;
    private Collector collector;
    private boolean collected;

    /**
     * Sets the input row from left table, which will be used to cross join with the result of table
     * function.
     */
    public void setInput(Object input) {
        this.input = input;
    }

    /**
     * Gets the input value from left table, which will be used to cross join with the result of
     * table function.
     */
    public Object getInput() {
        return input;
    }

    /** Sets the current collector, which used to emit the final row. */
    public void setCollector(Collector collector) {
        this.collector = collector;
    }

    /** Resets the flag to indicate whether [[collect(T)]] has been called. */
    public void reset() {
        this.collected = false;
        if (collector instanceof TableFunctionCollector) {
            ((TableFunctionCollector) collector).reset();
        }
    }

    /** Output final result of this UDTF to downstreams. */
    @SuppressWarnings("unchecked")
    public void outputResult(Object result) {
        this.collected = true;
        this.collector.collect(result);
    }

    /**
     * Whether {@link #collect(Object)} has been called.
     *
     * @return True if {@link #collect(Object)} has been called.
     */
    public boolean isCollected() {
        return collected;
    }

    public void close() {
        this.collector.close();
    }
}