/*
* 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.operators;
import java.util.Map;
import org.apache.flink.annotation.Internal;
import org.apache.flink.annotation.Public;
import org.apache.flink.api.common.operators.SemanticProperties;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.api.java.DataSet;
/**
* This interface marks operators as operators that execute user-defined functions (UDFs), such as
* {@link org.apache.flink.api.common.functions.RichMapFunction}, {@link org.apache.flink.api.common.functions.RichReduceFunction},
* or {@link org.apache.flink.api.common.functions.RichCoGroupFunction}.
* The UDF operators stand in contrast to operators that execute built-in operations, like aggregations.
*/
@Public
public interface UdfOperator<O extends UdfOperator<O>> {
// --------------------------------------------------------------------------------------------
// Accessors
// --------------------------------------------------------------------------------------------
/**
* Gets the configuration parameters that will be passed to the UDF's open method
* {@link org.apache.flink.api.common.functions.AbstractRichFunction#open(Configuration)}.
* The configuration is set via the {@link #withParameters(Configuration)}
* method.
*
* @return The configuration parameters for the UDF.
*/
Configuration getParameters();
/**
* Gets the broadcast sets (name and data set) that have been added to context of the UDF.
* Broadcast sets are added to a UDF via the method {@link #withBroadcastSet(DataSet, String)}.
*
* @return The broadcast data sets that have been added to this UDF.
*/
@Internal
Map<String, DataSet<?>> getBroadcastSets();
/**
* Gets the semantic properties that have been set for the user-defined functions (UDF).
*
* @return The semantic properties of the UDF.
*/
@Internal
SemanticProperties getSemanticProperties();
// --------------------------------------------------------------------------------------------
// Fluent API methods
// --------------------------------------------------------------------------------------------
/**
* Sets the configuration parameters for the UDF. These are optional parameters that are passed
* to the UDF in the {@link org.apache.flink.api.common.functions.AbstractRichFunction#open(Configuration)} method.
*
* @param parameters The configuration parameters for the UDF.
* @return The operator itself, to allow chaining function calls.
*/
O withParameters(Configuration parameters);
/**
* Adds a certain data set as a broadcast set to this operator. Broadcasted data sets are available at all
* parallel instances of this operator. A broadcast data set is registered under a certain name, and can be
* retrieved under that name from the operators runtime context via
* {@link org.apache.flink.api.common.functions.RuntimeContext#getBroadcastVariable(String)}.
*
* The runtime context itself is available in all UDFs via
* {@link org.apache.flink.api.common.functions.AbstractRichFunction#getRuntimeContext()}.
*
* @param data The data set to be broadcasted.
* @param name The name under which the broadcast data set retrieved.
* @return The operator itself, to allow chaining function calls.
*/
O withBroadcastSet(DataSet<?> data, String name);
}