wayang-plugins/wayang-iejoin/src/main/java/org/apache/wayang/iejoin/operators/IEJoinMasterOperator.java

/*
 * 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.wayang.iejoin.operators;

import org.apache.wayang.basic.data.Tuple5;

/**
 * This operator decides the correct sorting orders for IEJoin
 */
public class IEJoinMasterOperator {
    public static Tuple5<Boolean, Boolean, Boolean, Boolean, Boolean> getSortOrders(JoinCondition cond0, JoinCondition cond1) {
        boolean list1ASC = false;
        boolean list1ASCSec = false;
        boolean list2ASC = false;
        boolean list2ASCSec = false;
        boolean equalReverse = false;

        if (cond0 == JoinCondition.LessThan) {//"<") {
            list1ASC = true;
            list2ASCSec = true;
        } else if (cond0 == JoinCondition.LessThanEqual) {//attSymbols.get(0) == "<=") {
            list1ASC = true;
            list2ASCSec = false;
        } else if (cond0 == JoinCondition.GreaterThan) {//attSymbols.get(0) == ">") {
            list1ASC = false;
            list2ASCSec = false;
        } else if (cond0 == JoinCondition.GreaterThanEqual) {//(attSymbols.get(0) == ">=") {
            list1ASC = false;
            list2ASCSec = true;
        }

        // Reference and secondry pivot sort order
        if (cond1 == JoinCondition.GreaterThan) {//attSymbols.get(1) == ">") {
            list2ASC = true;
            list1ASCSec = true;
        } else if (cond1 == JoinCondition.GreaterThanEqual) {//attSymbols.get(1) == ">=") {
            list2ASC = true;
            list1ASCSec = false;
        } else if (cond1 == JoinCondition.LessThan) {//attSymbols.get(1) == "<") {
            list2ASC = false;
            list1ASCSec = false;
        } else if (cond1 == JoinCondition.LessThanEqual) {//attSymbols.get(1) == "<=") {
            list2ASC = false;
            list1ASCSec = true;
        }

        // For equal pivot and reference
        if (list1ASC != list2ASCSec && list2ASC != list1ASCSec) {
            equalReverse = true;
        }

        return new Tuple5<Boolean, Boolean, Boolean, Boolean, Boolean>(list1ASC, list1ASCSec, list2ASC, list2ASCSec, equalReverse);
    }

    /**
     * Created by khayyzy on 5/19/16.
     */
    public enum JoinCondition {
        GreaterThan, GreaterThanEqual, LessThan, LessThanEqual
    }
}