org.apache.flink.streaming.api.functions.windowing

Class FoldApplyAllWindowFunction<W extends Window,T,ACC>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.api.java.operators.translation.WrappingFunction<AllWindowFunction<ACC,ACC,W>>

org.apache.flink.streaming.api.functions.windowing.FoldApplyAllWindowFunction<W,T,ACC>

All Implemented Interfaces:

Serializable, Function, RichFunction, AllWindowFunction<T,ACC,W>, OutputTypeConfigurable<ACC>

@Internal
public class FoldApplyAllWindowFunction<W extends Window,T,ACC>
extends WrappingFunction<AllWindowFunction<ACC,ACC,W>>
implements AllWindowFunction<T,ACC,W>, OutputTypeConfigurable<ACC>

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.flink.api.java.operators.translation.WrappingFunction

wrappedFunction

Constructor Summary

Constructors

Constructor and Description
FoldApplyAllWindowFunction(ACC initialValue, FoldFunction<T,ACC> foldFunction, AllWindowFunction<ACC,ACC,W> windowFunction)

Method Summary

Modifier and Type	Method and Description
void	apply(W window, Iterable<T> values, Collector<ACC> out) Evaluates the window and outputs none or several elements.
void	open(Configuration configuration) Initialization method for the function.
void	setOutputType(TypeInformation<ACC> outTypeInfo, ExecutionConfig executionConfig) Is called by the org.apache.flink.streaming.api.graph.StreamGraph#addOperator(Integer, StreamOperator, TypeInformation, TypeInformation, String) method when the StreamGraph is generated.

Methods inherited from class org.apache.flink.api.java.operators.translation.WrappingFunction

close, getWrappedFunction, setRuntimeContext

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

getIterationRuntimeContext, getRuntimeContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FoldApplyAllWindowFunction

public FoldApplyAllWindowFunction(ACC initialValue,
                                  FoldFunction<T,ACC> foldFunction,
                                  AllWindowFunction<ACC,ACC,W> windowFunction)

Method Detail

open

public void open(Configuration configuration)
          throws Exception

Description copied from interface: RichFunction

Initialization method for the function. It is called before the actual working methods (like map or join) and thus suitable for one time setup work. For functions that are part of an iteration, this method will be invoked at the beginning of each iteration superstep.

The configuration object passed to the function can be used for configuration and initialization. The configuration contains all parameters that were configured on the function in the program composition.

 public class MyMapper extends FilterFunction<String> {
 
     private String searchString;
     
     public void open(Configuration parameters) {
         this.searchString = parameters.getString("foo");
     }
     
     public boolean filter(String value) {
         return value.equals(searchString);
     }
 }
 

By default, this method does nothing.

Specified by:

open in interface RichFunction

Overrides:

open in class WrappingFunction<AllWindowFunction<ACC,ACC,W extends Window>>

Parameters:

configuration - The configuration containing the parameters attached to the contract.

Throws:

Exception - Implementations may forward exceptions, which are caught by the runtime. When the runtime catches an exception, it aborts the task and lets the fail-over logic decide whether to retry the task execution.

See Also:

Configuration

apply

public void apply(W window,
                  Iterable<T> values,
                  Collector<ACC> out)
           throws Exception

Description copied from interface: AllWindowFunction

Evaluates the window and outputs none or several elements.

Specified by:

apply in interface AllWindowFunction<T,ACC,W extends Window>

Parameters:

window - The window that is being evaluated.

values - The elements in the window being evaluated.

out - A collector for emitting elements.

Throws:

Exception - The function may throw exceptions to fail the program and trigger recovery.

setOutputType

public void setOutputType(TypeInformation<ACC> outTypeInfo,
                          ExecutionConfig executionConfig)

Description copied from interface: OutputTypeConfigurable

Is called by the org.apache.flink.streaming.api.graph.StreamGraph#addOperator(Integer, StreamOperator, TypeInformation, TypeInformation, String) method when the StreamGraph is generated. The method is called with the output TypeInformation which is also used for the StreamTask output serializer.

Specified by:

setOutputType in interface OutputTypeConfigurable<ACC>

Parameters:

outTypeInfo - Output type information of the StreamTask

executionConfig - Execution configuration