org.apache.flink.table.runtime.generated

Interface NamespaceAggsHandleFunction<N>

Type Parameters:

N - type of namespace

All Superinterfaces:

org.apache.flink.api.common.functions.Function, Serializable

public interface NamespaceAggsHandleFunction<N>
extends org.apache.flink.api.common.functions.Function

The base class for handling aggregate functions.

The differences between NamespaceAggsHandleFunction and AggsHandleFunction is that the NamespaceAggsHandleFunction has namespace.

Method Summary

Modifier and Type	Method and Description
void	accumulate(BaseRow inputRow) Accumulates the input values to the accumulators.
void	cleanup(N namespace) Cleanup for the retired accumulators state.
void	close() Tear-down method for this function.
BaseRow	createAccumulators() Initializes the accumulators and save them to a accumulators row.
BaseRow	getAccumulators() Gets the current accumulators (saved in a row) which contains the current aggregated results.
BaseRow	getValue(N namespace) Gets the result of the aggregation from the current accumulators and namespace properties (like window start).
void	merge(N namespace, BaseRow otherAcc) Merges the other accumulators into current accumulators.
void	open(StateDataViewStore store) Initialization method for the function.
void	retract(BaseRow inputRow) Retracts the input values from the accumulators.
void	setAccumulators(N namespace, BaseRow accumulators) Set the current accumulators (saved in a row) which contains the current aggregated results.

Method Detail

open

void open(StateDataViewStore store)
   throws Exception

Initialization method for the function. It is called before the actual working methods.

Throws:

Exception

setAccumulators

void setAccumulators(N namespace,
                     BaseRow accumulators)
              throws Exception

Set the current accumulators (saved in a row) which contains the current aggregated results.

Parameters:

accumulators - current accumulators

Throws:

Exception

accumulate

void accumulate(BaseRow inputRow)
         throws Exception

Accumulates the input values to the accumulators.

Parameters:

inputRow - input values bundled in a row

Throws:

Exception

retract

void retract(BaseRow inputRow)
      throws Exception

Retracts the input values from the accumulators.

Parameters:

inputRow - input values bundled in a row

Throws:

Exception

merge

void merge(N namespace,
           BaseRow otherAcc)
    throws Exception

Merges the other accumulators into current accumulators.

Parameters:

otherAcc - The other row of accumulators

Throws:

Exception

createAccumulators

BaseRow createAccumulators()
                    throws Exception

Initializes the accumulators and save them to a accumulators row.

Returns:

a row of accumulators which contains the aggregated results

Throws:

Exception

getAccumulators

BaseRow getAccumulators()
                 throws Exception

Gets the current accumulators (saved in a row) which contains the current aggregated results.

Returns:

the current accumulators

Throws:

Exception

getValue

BaseRow getValue(N namespace)
          throws Exception

Gets the result of the aggregation from the current accumulators and namespace properties (like window start).

Parameters:

namespace - the namespace properties which should be calculated, such window start

Returns:

the final result (saved in a row) of the current accumulators.

Throws:

Exception

cleanup

void cleanup(N namespace)
      throws Exception

Cleanup for the retired accumulators state.

Throws:

Exception

close

void close()
    throws Exception

Tear-down method for this function. It can be used for clean up work. By default, this method does nothing.

Throws:

Exception