[FLINK-5250] Unwrap WrappingFunction in AbstractStreamOperator.setOutputType()

This makes InternalWindowFunction subclasses WrappingFunctions and
correctly forwards calls to setOutputType() by unwrapping
WrappingFunction in the newly added StreamingFunctionUtils.

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/util/StreamingFunctionUtils.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.streaming.api.functions.util;
+
+import org.apache.flink.annotation.Internal;
+import org.apache.flink.api.common.ExecutionConfig;
+import org.apache.flink.api.common.functions.Function;
+import org.apache.flink.api.common.state.ListState;
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.operators.translation.WrappingFunction;
+import org.apache.flink.runtime.state.DefaultOperatorStateBackend;
+import org.apache.flink.runtime.state.OperatorStateBackend;
+import org.apache.flink.runtime.state.StateInitializationContext;
+import org.apache.flink.runtime.state.StateSnapshotContext;
+import org.apache.flink.streaming.api.checkpoint.CheckpointedFunction;
+import org.apache.flink.streaming.api.checkpoint.ListCheckpointed;
+import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
+import org.apache.flink.util.Preconditions;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Utility class that contains helper methods to work with Flink Streaming
+ * {@link Function Functions}. This is similar to
+ * {@link org.apache.flink.api.common.functions.util.FunctionUtils} but has additional methods
+ * for invoking interfaces that only exist in the streaming API.
+ */
+@Internal
+public final class StreamingFunctionUtils {
+
+	@SuppressWarnings("unchecked")
+	public static <T> void setOutputType(
+			Function userFunction,
+			TypeInformation<T> outTypeInfo,
+			ExecutionConfig executionConfig) {
+
+		Preconditions.checkNotNull(outTypeInfo);
+		Preconditions.checkNotNull(executionConfig);
+
+		while (true) {
+			if (trySetOutputType(userFunction, outTypeInfo, executionConfig)) {
+				break;
+			}
+
+			// inspect if the user function is wrapped, then unwrap and try again if we can snapshot the inner function
+			if (userFunction instanceof WrappingFunction) {
+				userFunction = ((WrappingFunction<?>) userFunction).getWrappedFunction();
+			} else {
+				break;
+			}
+
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private static  <T> boolean trySetOutputType(
+			Function userFunction,
+			TypeInformation<T> outTypeInfo,
+			ExecutionConfig executionConfig) {
+
+		Preconditions.checkNotNull(outTypeInfo);
+		Preconditions.checkNotNull(executionConfig);
+
+		if (OutputTypeConfigurable.class.isAssignableFrom(userFunction.getClass())) {
+			((OutputTypeConfigurable<T>) userFunction).setOutputType(outTypeInfo, executionConfig);
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Private constructor to prevent instantiation.
+	 */
+	private StreamingFunctionUtils() {
+		throw new RuntimeException();
+	}
+}

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/graph/StreamGraph.java

@@ -202,7 +202,7 @@ public class StreamGraph extends StreamingPlan {
 
 		setSerializers(vertexID, inSerializer, null, outSerializer);
 
-		if (operatorObject instanceof OutputTypeConfigurable) {
+		if (operatorObject instanceof OutputTypeConfigurable && outTypeInfo != null) {
 			@SuppressWarnings("unchecked")
 			OutputTypeConfigurable<OUT> outputTypeConfigurable = (OutputTypeConfigurable<OUT>) operatorObject;
 			// sets the output type which must be know at StreamGraph creation time

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/operators/AbstractUdfStreamOperator.java

@@ -35,6 +35,7 @@ import org.apache.flink.streaming.api.checkpoint.Checkpointed;
 import org.apache.flink.streaming.api.checkpoint.CheckpointedFunction;
 import org.apache.flink.streaming.api.checkpoint.CheckpointedRestoring;
 import org.apache.flink.streaming.api.checkpoint.ListCheckpointed;
+import org.apache.flink.streaming.api.functions.util.StreamingFunctionUtils;
 import org.apache.flink.streaming.api.graph.StreamConfig;
 import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
 import org.apache.flink.streaming.runtime.tasks.StreamTask;
@@ -241,11 +242,7 @@ public abstract class AbstractUdfStreamOperator<OUT, F extends Function>
 
 	@Override
 	public void setOutputType(TypeInformation<OUT> outTypeInfo, ExecutionConfig executionConfig) {
-		if (userFunction instanceof OutputTypeConfigurable) {
-			@SuppressWarnings("unchecked")
-			OutputTypeConfigurable<OUT> outputTypeConfigurable = (OutputTypeConfigurable<OUT>) userFunction;
-			outputTypeConfigurable.setOutputType(outTypeInfo, executionConfig);
-		}
+		StreamingFunctionUtils.setOutputType(userFunction, outTypeInfo, executionConfig);
 	}
 
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/functions/InternalIterableAllWindowFunction.java

@@ -17,15 +17,12 @@
  */
 package org.apache.flink.streaming.runtime.operators.windowing.functions;
 
-import org.apache.flink.api.common.ExecutionConfig;
 import org.apache.flink.api.common.functions.IterationRuntimeContext;
-import org.apache.flink.api.common.functions.RichFunction;
 import org.apache.flink.api.common.functions.RuntimeContext;
 import org.apache.flink.api.common.functions.util.FunctionUtils;
-import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.operators.translation.WrappingFunction;
 import org.apache.flink.configuration.Configuration;
 import org.apache.flink.streaming.api.functions.windowing.AllWindowFunction;
-import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
 import org.apache.flink.streaming.api.windowing.windows.Window;
 import org.apache.flink.util.Collector;
 
@@ -34,14 +31,15 @@ import org.apache.flink.util.Collector;
  * when the window state also is an {@code Iterable}.
  */
 public final class InternalIterableAllWindowFunction<IN, OUT, W extends Window>
-		extends InternalWindowFunction<Iterable<IN>, OUT, Byte, W>
-		implements RichFunction {
+		extends WrappingFunction<AllWindowFunction<IN, OUT, W>>
+		implements InternalWindowFunction<Iterable<IN>, OUT, Byte, W> {
 
 	private static final long serialVersionUID = 1L;
 
 	protected final AllWindowFunction<IN, OUT, W> wrappedFunction;
 
 	public InternalIterableAllWindowFunction(AllWindowFunction<IN, OUT, W> wrappedFunction) {
+		super(wrappedFunction);
 		this.wrappedFunction = wrappedFunction;
 	}
 
@@ -75,12 +73,4 @@ public final class InternalIterableAllWindowFunction<IN, OUT, W extends Window>
 		throw new RuntimeException("This should never be called.");
 
 	}
-
-	@SuppressWarnings("unchecked")
-	@Override
-	public void setOutputType(TypeInformation<OUT> outTypeInfo, ExecutionConfig executionConfig) {
-		if (OutputTypeConfigurable.class.isAssignableFrom(this.wrappedFunction.getClass())) {
-			((OutputTypeConfigurable<OUT>)this.wrappedFunction).setOutputType(outTypeInfo, executionConfig);
-		}
-	}
 }

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/functions/InternalIterableWindowFunction.java

@@ -17,15 +17,12 @@
  */
 package org.apache.flink.streaming.runtime.operators.windowing.functions;
 
-import org.apache.flink.api.common.ExecutionConfig;
 import org.apache.flink.api.common.functions.IterationRuntimeContext;
-import org.apache.flink.api.common.functions.RichFunction;
 import org.apache.flink.api.common.functions.RuntimeContext;
 import org.apache.flink.api.common.functions.util.FunctionUtils;
-import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.operators.translation.WrappingFunction;
 import org.apache.flink.configuration.Configuration;
 import org.apache.flink.streaming.api.functions.windowing.WindowFunction;
-import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
 import org.apache.flink.streaming.api.windowing.windows.Window;
 import org.apache.flink.util.Collector;
 
@@ -34,14 +31,15 @@ import org.apache.flink.util.Collector;
  * when the window state also is an {@code Iterable}.
  */
 public final class InternalIterableWindowFunction<IN, OUT, KEY, W extends Window>
-		extends InternalWindowFunction<Iterable<IN>, OUT, KEY, W>
-		implements RichFunction {
+		extends WrappingFunction<WindowFunction<IN, OUT, KEY, W>>
+		implements InternalWindowFunction<Iterable<IN>, OUT, KEY, W> {
 
 	private static final long serialVersionUID = 1L;
 
 	protected final WindowFunction<IN, OUT, KEY, W> wrappedFunction;
 
 	public InternalIterableWindowFunction(WindowFunction<IN, OUT, KEY, W> wrappedFunction) {
+		super(wrappedFunction);
 		this.wrappedFunction = wrappedFunction;
 	}
 
@@ -75,12 +73,4 @@ public final class InternalIterableWindowFunction<IN, OUT, KEY, W extends Window
 		throw new RuntimeException("This should never be called.");
 
 	}
-
-	@SuppressWarnings("unchecked")
-	@Override
-	public void setOutputType(TypeInformation<OUT> outTypeInfo, ExecutionConfig executionConfig) {
-		if (OutputTypeConfigurable.class.isAssignableFrom(this.wrappedFunction.getClass())) {
-			((OutputTypeConfigurable<OUT>)this.wrappedFunction).setOutputType(outTypeInfo, executionConfig);
-		}
-	}
 }

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/functions/InternalSingleValueAllWindowFunction.java

@@ -17,15 +17,12 @@
  */
 package org.apache.flink.streaming.runtime.operators.windowing.functions;
 
-import org.apache.flink.api.common.ExecutionConfig;
 import org.apache.flink.api.common.functions.IterationRuntimeContext;
-import org.apache.flink.api.common.functions.RichFunction;
 import org.apache.flink.api.common.functions.RuntimeContext;
 import org.apache.flink.api.common.functions.util.FunctionUtils;
-import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.operators.translation.WrappingFunction;
 import org.apache.flink.configuration.Configuration;
 import org.apache.flink.streaming.api.functions.windowing.AllWindowFunction;
-import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
 import org.apache.flink.streaming.api.windowing.windows.Window;
 import org.apache.flink.util.Collector;
 
@@ -36,14 +33,15 @@ import java.util.Collections;
  * when the window state is a single value.
  */
 public final class InternalSingleValueAllWindowFunction<IN, OUT, W extends Window>
-		extends InternalWindowFunction<IN, OUT, Byte, W>
-		implements RichFunction {
+		extends WrappingFunction<AllWindowFunction<IN, OUT, W>>
+		implements InternalWindowFunction<IN, OUT, Byte, W> {
 
 	private static final long serialVersionUID = 1L;
 
 	protected AllWindowFunction<IN, OUT, W> wrappedFunction;
 
 	public InternalSingleValueAllWindowFunction(AllWindowFunction<IN, OUT, W> wrappedFunction) {
+		super(wrappedFunction);
 		this.wrappedFunction = wrappedFunction;
 	}
 
@@ -77,12 +75,4 @@ public final class InternalSingleValueAllWindowFunction<IN, OUT, W extends Windo
 		throw new RuntimeException("This should never be called.");
 
 	}
-
-	@SuppressWarnings("unchecked")
-	@Override
-	public void setOutputType(TypeInformation<OUT> outTypeInfo, ExecutionConfig executionConfig) {
-		if (OutputTypeConfigurable.class.isAssignableFrom(this.wrappedFunction.getClass())) {
-			((OutputTypeConfigurable<OUT>)this.wrappedFunction).setOutputType(outTypeInfo, executionConfig);
-		}
-	}
 }

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/functions/InternalSingleValueWindowFunction.java

@@ -17,15 +17,12 @@
  */
 package org.apache.flink.streaming.runtime.operators.windowing.functions;
 
-import org.apache.flink.api.common.ExecutionConfig;
 import org.apache.flink.api.common.functions.IterationRuntimeContext;
-import org.apache.flink.api.common.functions.RichFunction;
 import org.apache.flink.api.common.functions.RuntimeContext;
 import org.apache.flink.api.common.functions.util.FunctionUtils;
-import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.java.operators.translation.WrappingFunction;
 import org.apache.flink.configuration.Configuration;
 import org.apache.flink.streaming.api.functions.windowing.WindowFunction;
-import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
 import org.apache.flink.streaming.api.windowing.windows.Window;
 import org.apache.flink.util.Collector;
 
@@ -36,14 +33,15 @@ import java.util.Collections;
  * when the window state is a single value.
  */
 public final class InternalSingleValueWindowFunction<IN, OUT, KEY, W extends Window>
-		extends InternalWindowFunction<IN, OUT, KEY, W>
-		implements RichFunction {
+		extends WrappingFunction<WindowFunction<IN, OUT, KEY, W>>
+		implements InternalWindowFunction<IN, OUT, KEY, W> {
 
 	private static final long serialVersionUID = 1L;
 
 	protected WindowFunction<IN, OUT, KEY, W> wrappedFunction;
 
 	public InternalSingleValueWindowFunction(WindowFunction<IN, OUT, KEY, W> wrappedFunction) {
+		super(wrappedFunction);
 		this.wrappedFunction = wrappedFunction;
 	}
 
@@ -77,12 +75,4 @@ public final class InternalSingleValueWindowFunction<IN, OUT, KEY, W extends Win
 		throw new RuntimeException("This should never be called.");
 
 	}
-
-	@SuppressWarnings("unchecked")
-	@Override
-	public void setOutputType(TypeInformation<OUT> outTypeInfo, ExecutionConfig executionConfig) {
-		if (OutputTypeConfigurable.class.isAssignableFrom(this.wrappedFunction.getClass())) {
-			((OutputTypeConfigurable<OUT>)this.wrappedFunction).setOutputType(outTypeInfo, executionConfig);
-		}
-	}
 }

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/functions/InternalWindowFunction.java

@@ -18,12 +18,9 @@
 package org.apache.flink.streaming.runtime.operators.windowing.functions;
 
 import org.apache.flink.api.common.functions.Function;
-import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
 import org.apache.flink.streaming.api.windowing.windows.Window;
 import org.apache.flink.util.Collector;
 
-import java.io.Serializable;
-
 /**
  * Internal interface for functions that are evaluated over keyed (grouped) windows.
  *
@@ -31,20 +28,16 @@ import java.io.Serializable;
  * @param <OUT> The type of the output value.
  * @param <KEY> The type of the key.
  */
-public abstract class InternalWindowFunction<IN, OUT, KEY, W extends Window>
-		implements Function, Serializable, OutputTypeConfigurable<OUT> {
-
-	private static final long serialVersionUID = 1L;
+public interface InternalWindowFunction<IN, OUT, KEY, W extends Window> extends Function {
 
 	/**
 	 * Evaluates the window and outputs none or several elements.
 	 *
-	 * @param key The key for which this window is evaluated.
+	 * @param key    The key for which this window is evaluated.
 	 * @param window The window that is being evaluated.
-	 * @param input The elements in the window being evaluated.
-	 * @param out A collector for emitting elements.
-	 *
+	 * @param input  The elements in the window being evaluated.
+	 * @param out    A collector for emitting elements.
 	 * @throws Exception The function may throw exceptions to fail the program and trigger recovery.
 	 */
-	public abstract void apply(KEY key, W window, IN input, Collector<OUT> out) throws Exception;
+	void apply(KEY key, W window, IN input, Collector<OUT> out) throws Exception;
 }

flink-streaming-java/src/test/java/org/apache/flink/streaming/api/operators/windowing/functions/InternalWindowFunctionTest.java

@@ -23,6 +23,7 @@ import org.apache.flink.api.common.functions.RuntimeContext;
 import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
 import org.apache.flink.api.common.typeinfo.TypeInformation;
 import org.apache.flink.configuration.Configuration;
+import org.apache.flink.streaming.api.functions.util.StreamingFunctionUtils;
 import org.apache.flink.streaming.api.functions.windowing.RichAllWindowFunction;
 import org.apache.flink.streaming.api.functions.windowing.RichWindowFunction;
 import org.apache.flink.streaming.api.operators.OutputTypeConfigurable;
@@ -52,7 +53,7 @@ public class InternalWindowFunctionTest {
 		ExecutionConfig execConf = new ExecutionConfig();
 		execConf.setParallelism(42);
 
-		windowFunction.setOutputType(stringType, execConf);
+		StreamingFunctionUtils.setOutputType(windowFunction, stringType, execConf);
 		verify(mock).setOutputType(stringType, execConf);
 
 		// check open
@@ -93,7 +94,7 @@ public class InternalWindowFunctionTest {
 		ExecutionConfig execConf = new ExecutionConfig();
 		execConf.setParallelism(42);
 
-		windowFunction.setOutputType(stringType, execConf);
+		StreamingFunctionUtils.setOutputType(windowFunction, stringType, execConf);
 		verify(mock).setOutputType(stringType, execConf);
 
 		// check open
@@ -134,7 +135,8 @@ public class InternalWindowFunctionTest {
 		ExecutionConfig execConf = new ExecutionConfig();
 		execConf.setParallelism(42);
 
-		windowFunction.setOutputType(stringType, execConf);
+		StreamingFunctionUtils.setOutputType(windowFunction, stringType, execConf);
+
 		verify(mock).setOutputType(stringType, execConf);
 
 		// check open
@@ -174,7 +176,8 @@ public class InternalWindowFunctionTest {
 		ExecutionConfig execConf = new ExecutionConfig();
 		execConf.setParallelism(42);
 
-		windowFunction.setOutputType(stringType, execConf);
+		StreamingFunctionUtils.setOutputType(windowFunction, stringType, execConf);
+
 		verify(mock).setOutputType(stringType, execConf);
 
 		// check open
@@ -205,6 +208,8 @@ public class InternalWindowFunctionTest {
 		extends RichWindowFunction<Long, String, Long, TimeWindow>
 		implements OutputTypeConfigurable<String> {
 
+		private static final long serialVersionUID = 1L;
+
 		@Override
 		public void setOutputType(TypeInformation<String> outTypeInfo, ExecutionConfig executionConfig) { }
 
@@ -216,6 +221,8 @@ public class InternalWindowFunctionTest {
 		extends RichAllWindowFunction<Long, String, TimeWindow>
 		implements OutputTypeConfigurable<String> {
 
+		private static final long serialVersionUID = 1L;
+
 		@Override
 		public void setOutputType(TypeInformation<String> outTypeInfo, ExecutionConfig executionConfig) { }