[FLINK-1110] Add execution on collections for flatMap

flink-core/src/main/java/org/apache/flink/api/common/operators/base/FlatMapOperatorBase.java

@@ -16,16 +16,20 @@
  * limitations under the License.
  */
 
-
 package org.apache.flink.api.common.operators.base;
 
 import org.apache.flink.api.common.functions.FlatMapFunction;
+import org.apache.flink.api.common.functions.RuntimeContext;
+import org.apache.flink.api.common.functions.util.FunctionUtils;
+import org.apache.flink.api.common.functions.util.ListCollector;
 import org.apache.flink.api.common.operators.SingleInputOperator;
 import org.apache.flink.api.common.operators.UnaryOperatorInformation;
 import org.apache.flink.api.common.operators.util.UserCodeClassWrapper;
 import org.apache.flink.api.common.operators.util.UserCodeObjectWrapper;
 import org.apache.flink.api.common.operators.util.UserCodeWrapper;
 
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * @see org.apache.flink.api.common.functions.FlatMapFunction
@@ -35,12 +39,33 @@ public class FlatMapOperatorBase<IN, OUT, FT extends FlatMapFunction<IN, OUT>> e
 	public FlatMapOperatorBase(UserCodeWrapper<FT> udf, UnaryOperatorInformation<IN, OUT> operatorInfo, String name) {
 		super(udf, operatorInfo, name);
 	}
-	
+
 	public FlatMapOperatorBase(FT udf, UnaryOperatorInformation<IN, OUT> operatorInfo, String name) {
 		super(new UserCodeObjectWrapper<FT>(udf), operatorInfo, name);
 	}
-	
+
 	public FlatMapOperatorBase(Class<? extends FT> udf, UnaryOperatorInformation<IN, OUT> operatorInfo, String name) {
 		super(new UserCodeClassWrapper<FT>(udf), operatorInfo, name);
 	}
+
+	// ------------------------------------------------------------------------
+
+	@Override
+	protected List<OUT> executeOnCollections(List<IN> input, RuntimeContext ctx) throws Exception {
+		FlatMapFunction<IN, OUT> function = userFunction.getUserCodeObject();
+
+		FunctionUtils.setFunctionRuntimeContext(function, ctx);
+		FunctionUtils.openFunction(function, parameters);
+
+		ArrayList<OUT> result = new ArrayList<OUT>(input.size());
+		ListCollector<OUT> resultCollector = new ListCollector<OUT>(result);
+
+		for (IN element : input) {
+			function.flatMap(element, resultCollector);
+		}
+
+		FunctionUtils.closeFunction(function);
+
+		return result;
+	}
 }

flink-core/src/test/java/org/apache/flink/api/common/operators/base/FlatMapOperatorCollectionExecutionTest.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.common.operators.base;
+
+import org.apache.flink.api.common.functions.FlatMapFunction;
+import org.apache.flink.api.common.functions.RichFlatMapFunction;
+import org.apache.flink.api.common.functions.RuntimeContext;
+import org.apache.flink.api.common.functions.util.RuntimeUDFContext;
+import org.apache.flink.api.common.operators.UnaryOperatorInformation;
+import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.util.Collector;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class FlatMapOperatorCollectionExecutionTest implements Serializable {
+
+	@Test
+	public void testExecuteOnCollection() {
+		try {
+			IdRichFlatMap<String> udf = new IdRichFlatMap<String>();
+			testExecuteOnCollection(udf, Arrays.asList("f", "l", "i", "n", "k"));
+			Assert.assertTrue(udf.isClosed);
+
+			testExecuteOnCollection(new IdRichFlatMap<String>(), new ArrayList<String>());
+		} catch (Throwable t) {
+			Assert.fail(t.getMessage());
+		}
+	}
+
+	private void testExecuteOnCollection(FlatMapFunction<String, String> udf, List<String> input) throws Exception {
+		// run on collections
+		final List<String> result = getTestFlatMapOperator(udf)
+				.executeOnCollections(input, new RuntimeUDFContext("Test UDF", 4, 0));
+
+		Assert.assertEquals(input.size(), result.size());
+
+		for (int i = 0; i < input.size(); i++) {
+			Assert.assertEquals(input.get(i), result.get(i));
+		}
+	}
+
+	public class IdRichFlatMap<IN> extends RichFlatMapFunction<IN, IN> {
+
+		private boolean isOpened = false;
+		private boolean isClosed = false;
+
+		@Override
+		public void open(Configuration parameters) throws Exception {
+			isOpened = true;
+
+			RuntimeContext ctx = getRuntimeContext();
+			Assert.assertEquals("Test UDF", ctx.getTaskName());
+			Assert.assertEquals(4, ctx.getNumberOfParallelSubtasks());
+			Assert.assertEquals(0, ctx.getIndexOfThisSubtask());
+		}
+
+		@Override
+		public void flatMap(IN value, Collector<IN> out) throws Exception {
+			Assert.assertTrue(isOpened);
+			Assert.assertFalse(isClosed);
+
+			out.collect(value);
+		}
+
+		@Override
+		public void close() throws Exception {
+			isClosed = true;
+		}
+	}
+
+	private FlatMapOperatorBase<String, String, FlatMapFunction<String, String>> getTestFlatMapOperator(
+			FlatMapFunction<String, String> udf) {
+
+		UnaryOperatorInformation<String, String> typeInfo = new UnaryOperatorInformation<String, String>(
+				BasicTypeInfo.STRING_TYPE_INFO, BasicTypeInfo.STRING_TYPE_INFO);
+
+		return new FlatMapOperatorBase<String, String, FlatMapFunction<String, String>>(
+				udf, typeInfo, "flatMap on Collections");
+	}
+}