GroupSortFlow.java

/**
 * Copyright 2011-2017 Asakusa Framework Team.
 *
 * Licensed 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 com.asakusafw.compiler.flow.processor.operator;

import java.util.List;

import com.asakusafw.compiler.flow.processor.CoGroupFlowProcessor;
import com.asakusafw.compiler.flow.testing.model.Ex1;
import com.asakusafw.runtime.core.Result;
import com.asakusafw.vocabulary.model.Key;
import com.asakusafw.vocabulary.operator.CoGroup;
import com.asakusafw.vocabulary.operator.GroupSort;

/**
 * An operator class for testing {@link GroupSort} (it is merged into {@link CoGroupFlowProcessor}).
 */
public abstract class GroupSortFlow {

    /**
     * return min.
     * @param a1 group
     * @param r1 result
     */
    @GroupSort
    public void min(
            @Key(group = "string", order = "value asc") List<Ex1> a1,
            Result<Ex1> r1) {
        r1.add(a1.get(0));
    }

    /**
     * return max.
     * @param a1 group
     * @param r1 result
     */
    @GroupSort
    public void max(
            @Key(group = "string", order = "value desc") List<Ex1> a1,
            Result<Ex1> r1) {
        r1.add(a1.get(0));
    }

    /**
     * Switches output target whether if the value is less than or equal to the parameter.
     * @param a1 group
     * @param r1 a1 where value of input is less than or equal to the parameter
     * @param r2 a1 where value of input is greater than the parameter
     * @param parameter the parameter for switching output target
     */
    @CoGroup
    public void withParameter(
            @Key(group = "string", order = "value asc") List<Ex1> a1,
            Result<Ex1> r1,
            Result<Ex1> r2,
            int parameter) {
        boolean over = false;
        for (Ex1 e : a1) {
            over |= (e.getValue() > parameter);
            if (over) {
                r2.add(e);
            } else {
                r1.add(e);
            }
        }
    }
}