Package org.apache.flink.state.api

Class WindowSavepointReader<W extends Window>

java.lang.Object

org.apache.flink.state.api.WindowSavepointReader<W>

Type Parameters:

W - The type of Window.

@PublicEvolving
public class WindowSavepointReader<W extends Window>
extends Object

This class provides entry points for reading keyed state written out using the WindowOperator.

Method Summary

Modifier and Type	Method	Description
<K,T,ACC,R> DataStream<R>	aggregate(String uid, AggregateFunction<T,ACC,R> aggregateFunction, TypeInformation<K> keyType, TypeInformation<ACC> accType, TypeInformation<R> outputType)	Reads window state generated using an AggregateFunction.
<K,T,ACC,R,OUT> DataStream<OUT>	aggregate(String uid, AggregateFunction<T,ACC,R> aggregateFunction, WindowReaderFunction<R,OUT,K,W> readerFunction, TypeInformation<K> keyType, TypeInformation<ACC> accType, TypeInformation<OUT> outputType)	Reads window state generated using an AggregateFunction.
EvictingWindowSavepointReader<W>	evictor()	Reads from a window that uses an evictor.
<K,T,OUT> DataStream<OUT>	process(String uid, WindowReaderFunction<T,OUT,K,W> readerFunction, TypeInformation<K> keyType, TypeInformation<T> stateType, TypeInformation<OUT> outputType)	Reads window state generated without any preaggregation such as WindowedStream#apply and WindowedStream#process.
<T,K> DataStream<T>	reduce(String uid, ReduceFunction<T> function, TypeInformation<K> keyType, TypeInformation<T> reduceType)	Reads window state generated using a ReduceFunction.
<K,T,OUT> DataStream<OUT>	reduce(String uid, ReduceFunction<T> function, WindowReaderFunction<T,OUT,K,W> readerFunction, TypeInformation<K> keyType, TypeInformation<T> reduceType, TypeInformation<OUT> outputType)	Reads window state generated using a ReduceFunction.

Methods inherited from class java.lang.Object

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

Method Detail

evictor

public EvictingWindowSavepointReader<W> evictor()

Reads from a window that uses an evictor.

reduce

public <T,K> DataStream<T> reduce(String uid,
                                        ReduceFunction<T> function,
                                        TypeInformation<K> keyType,
                                        TypeInformation<T> reduceType)
                                 throws IOException

Reads window state generated using a ReduceFunction.

Type Parameters:

T - The type of the reduce function.

K - The key type of the operator.

Parameters:

uid - The uid of the operator.

function - The reduce function used to create the window.

keyType - The key type of the window.

reduceType - The type information of the reduce function.

Returns:

A DataStream of objects read from keyed state.

Throws:

IOException - If savepoint does not contain the specified uid.

reduce

public <K,T,OUT> DataStream<OUT> reduce(String uid,
                                                    ReduceFunction<T> function,
                                                    WindowReaderFunction<T,OUT,K,W> readerFunction,
                                                    TypeInformation<K> keyType,
                                                    TypeInformation<T> reduceType,
                                                    TypeInformation<OUT> outputType)
                                             throws IOException

Reads window state generated using a ReduceFunction.

Type Parameters:

K - The type of the key.

T - The type of the reduce function.

OUT - The output type of the reduce function.

Parameters:

uid - The uid of the operator.

function - The reduce function used to create the window.

readerFunction - The window reader function.

keyType - The key type of the window.

reduceType - The type information of the reduce function.

outputType - The output type of the reader function.

Returns:

A DataStream of objects read from keyed state.

Throws:

IOException - If savepoint does not contain the specified uid.

aggregate

public <K,T,ACC,R> DataStream<R> aggregate(String uid,
                                                             AggregateFunction<T,ACC,R> aggregateFunction,
                                                             TypeInformation<K> keyType,
                                                             TypeInformation<ACC> accType,
                                                             TypeInformation<R> outputType)
                                                      throws IOException

Reads window state generated using an AggregateFunction.

Type Parameters:

K - The type of the key.

T - The type of the values that are aggregated.

ACC - The type of the accumulator (intermediate aggregate state).

R - The type of the aggregated result.

Parameters:

uid - The uid of the operator.

aggregateFunction - The aggregate function used to create the window.

keyType - The key type of the window.

accType - The type information of the accumulator function.

outputType - The output type of the reader function.

Returns:

A DataStream of objects read from keyed state.

Throws:

IOException - If savepoint does not contain the specified uid.

aggregate

public <K,T,ACC,R,OUT> DataStream<OUT> aggregate(String uid,
                                                                         AggregateFunction<T,ACC,R> aggregateFunction,
                                                                         WindowReaderFunction<R,OUT,K,W> readerFunction,
                                                                         TypeInformation<K> keyType,
                                                                         TypeInformation<ACC> accType,
                                                                         TypeInformation<OUT> outputType)
                                                                  throws IOException

Reads window state generated using an AggregateFunction.

Type Parameters:

K - The type of the key.

T - The type of the values that are aggregated.

ACC - The type of the accumulator (intermediate aggregate state).

R - The type of the aggregated result.

OUT - The output type of the reader function.

Parameters:

uid - The uid of the operator.

aggregateFunction - The aggregate function used to create the window.

readerFunction - The window reader function.

keyType - The key type of the window.

accType - The type information of the accumulator function.

outputType - The output type of the reader function.

Returns:

A DataStream of objects read from keyed state.

Throws:

IOException - If savepoint does not contain the specified uid.

process

public <K,T,OUT> DataStream<OUT> process(String uid,
                                                     WindowReaderFunction<T,OUT,K,W> readerFunction,
                                                     TypeInformation<K> keyType,
                                                     TypeInformation<T> stateType,
                                                     TypeInformation<OUT> outputType)
                                              throws IOException

Reads window state generated without any preaggregation such as WindowedStream#apply and WindowedStream#process.

Type Parameters:

K - The type of the key.

T - The type of the records stored in state.

OUT - The output type of the reader function.

Parameters:

uid - The uid of the operator.

readerFunction - The window reader function.

keyType - The key type of the window.

stateType - The type of records stored in state.

outputType - The output type of the reader function.

Returns:

A DataStream of objects read from keyed state.

Throws:

IOException - If the savepoint does not contain the specified uid.