Class EvictingWindowSavepointReader<W extends Window>

  • Type Parameters:
    W - The type of Window.

    @PublicEvolving
    public class EvictingWindowSavepointReader<W extends Window>
    extends Object
    This class provides entry points for reading keyed state written out using the WindowOperator.
    • Method Detail

      • 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<T> inputType,
                                                                     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.
        inputType - 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<T> inputType,
                                                                                 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.
        inputType - 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.