FirstNOperatorTest.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.flink.api.java.operator;

import java.util.ArrayList;
import java.util.List;

import org.apache.flink.api.common.InvalidProgramException;
import org.apache.flink.api.common.operators.Order;
import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple5;
import org.apache.flink.api.java.typeutils.TupleTypeInfo;
import org.junit.Assert;
import org.junit.Test;

public class FirstNOperatorTest {

	// TUPLE DATA
	
	private final List<Tuple5<Integer, Long, String, Long, Integer>> emptyTupleData = 
			new ArrayList<Tuple5<Integer, Long, String, Long, Integer>>();
	
	private final TupleTypeInfo<Tuple5<Integer, Long, String, Long, Integer>> tupleTypeInfo = new 
			TupleTypeInfo<Tuple5<Integer, Long, String, Long, Integer>>(
					BasicTypeInfo.INT_TYPE_INFO,
					BasicTypeInfo.LONG_TYPE_INFO,
					BasicTypeInfo.STRING_TYPE_INFO,
					BasicTypeInfo.LONG_TYPE_INFO,
					BasicTypeInfo.INT_TYPE_INFO
			);
	
	@Test
	public void testUngroupedFirstN() {
		
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should work
		try {
			tupleDs.first(1);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should work
		try {
			tupleDs.first(10);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == 0
		try {
			tupleDs.first(0);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == -1
		try {
			tupleDs.first(-1);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
		
	}
	
	@Test
	public void testGroupedFirstN() {
		
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should work
		try {
			tupleDs.groupBy(2).first(1);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should work
		try {
			tupleDs.groupBy(1,3).first(10);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == 0
		try {
			tupleDs.groupBy(0).first(0);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == -1
		try {
			tupleDs.groupBy(2).first(-1);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
	}
	
	@Test
	public void testGroupedSortedFirstN() {
		
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should work
		try {
			tupleDs.groupBy(2).sortGroup(4, Order.ASCENDING).first(1);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should work
		try {
			tupleDs.groupBy(1,3).sortGroup(4, Order.ASCENDING).first(10);
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == 0
		try {
			tupleDs.groupBy(0).sortGroup(4, Order.ASCENDING).first(0);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
		
		// should not work n == -1
		try {
			tupleDs.groupBy(2).sortGroup(4, Order.ASCENDING).first(-1);
			Assert.fail();
		} catch(InvalidProgramException ipe) {
			// we're good here
		} catch(Exception e) {
			Assert.fail();
		}
	}
}