flink-java/src/test/java/org/apache/flink/api/java/operator/DistinctOperatorTest.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 org.apache.flink.api.common.InvalidProgramException;
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.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple5;
import org.apache.flink.api.java.typeutils.TupleTypeInfo;

import org.junit.Assert;
import org.junit.Test;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

/**
 * Tests for {@link DataSet#distinct()}.
 */
public class DistinctOperatorTest {

	// 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
			);

	// LONG DATA
	private final List<Long> emptyLongData = new ArrayList<Long>();

	private final List<CustomType> customTypeData = new ArrayList<CustomType>();

	@Test
	public void testDistinctByKeyFields1() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should work
		try {
			tupleDs.distinct(0);
		} catch (Exception e) {
			Assert.fail();
		}
	}

	@Test(expected = InvalidProgramException.class)
	public void testDistinctByKeyFields2() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		DataSet<Long> longDs = env.fromCollection(emptyLongData, BasicTypeInfo.LONG_TYPE_INFO);
		// should not work: distinct on basic type
		longDs.distinct(0);
	}

	@Test(expected = InvalidProgramException.class)
	public void testDistinctByKeyFields3() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		this.customTypeData.add(new CustomType());

		DataSet<CustomType> customDs = env.fromCollection(customTypeData);
		// should not work: distinct on custom type
		customDs.distinct(0);

	}

	@Test
	public void testDistinctByKeyFields4() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should work
		tupleDs.distinct();
	}

	@Test
	public void testDistinctByKeyFields5() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		this.customTypeData.add(new CustomType());

		DataSet<CustomType> customDs = env.fromCollection(customTypeData);

		// should work
		customDs.distinct();
	}

	@Test(expected = IndexOutOfBoundsException.class)
	public void testDistinctByKeyFields6() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Tuple5<Integer, Long, String, Long, Integer>> tupleDs = env.fromCollection(emptyTupleData, tupleTypeInfo);

		// should not work, negative field position
		tupleDs.distinct(-1);
	}

	@Test
	public void testDistinctByKeyFields7(){
		final ExecutionEnvironment env  = ExecutionEnvironment.getExecutionEnvironment();
		DataSet<Long> longDs = env.fromCollection(emptyLongData, BasicTypeInfo.LONG_TYPE_INFO);

		// should work
		try {
			longDs.distinct("*");
		} catch (Exception e){
			Assert.fail();
		}
	}

	@Test
	@SuppressWarnings("serial")
	public void testDistinctByKeySelector1() {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		this.customTypeData.add(new CustomType());

		try {
			DataSet<CustomType> customDs = env.fromCollection(customTypeData);
			// should work
			customDs.distinct(
					new KeySelector<DistinctOperatorTest.CustomType, Long>() {

						@Override
						public Long getKey(CustomType value) {
							return value.myLong;
					}
			});
		} catch (Exception e) {
			Assert.fail();
		}

	}

	@Test
	public void  testDistinctByKeyIndices1() {
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		try {
			DataSet<Long> longDs = env.fromCollection(emptyLongData, BasicTypeInfo.LONG_TYPE_INFO);
			// should work
			longDs.distinct();
		} catch (Exception e) {
			Assert.fail();
		}
	}

	@Test(expected = InvalidProgramException.class)
	public void testDistinctOnNotKeyDataType() throws Exception {
    	/*
     	* should not work. NotComparable data type cannot be used as key
     	*/
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		NotComparable a = new NotComparable();
		List<NotComparable> l = new ArrayList<NotComparable>();
		l.add(a);

		DataSet<NotComparable> ds = env.fromCollection(l);
		DataSet<NotComparable> reduceDs = ds.distinct();

	}

	@Test(expected = InvalidProgramException.class)
	public void testDistinctOnNotKeyDataTypeOnSelectAllChar() throws Exception {
    	/*
     	* should not work. NotComparable data type cannot be used as key
     	*/
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		NotComparable a = new NotComparable();
		List<NotComparable> l = new ArrayList<NotComparable>();
		l.add(a);

		DataSet<NotComparable> ds = env.fromCollection(l);
		DataSet<NotComparable> reduceDs = ds.distinct("*");
	}

	class NotComparable {
		public List<Integer> myInts;
	}

	/**
	 * Custom data type, for testing purposes.
	 */
	public static class CustomType implements Serializable {

		private static final long serialVersionUID = 1L;

		public int myInt;
		public long myLong;
		public String myString;

		public CustomType() {}

		public CustomType(int i, long l, String s) {
			myInt = i;
			myLong = l;
			myString = s;
		}

		@Override
		public String toString() {
			return myInt + "," + myLong + "," + myString;
		}
	}

}