org.apache.flink.streaming.runtime.operators.windowing.buffers

Interface WindowBuffer<T,O>

Type Parameters:

T - The type of elements that this WindowBuffer can store.

O - The type of elements that this window buffer will return when asked for its contents.

All Known Subinterfaces:

EvictingWindowBuffer<T,O>

All Known Implementing Classes:

FoldingWindowBuffer, ListWindowBuffer, ReducingWindowBuffer

@Internal
public interface WindowBuffer<T,O>

A WindowBuffer is used by WindowOperator to store the elements of one pane.

A pane is the bucket of elements that have the same key (assigned by the KeySelector) and same Window. An element can be in multiple panes of it was assigned to multiple windows by the WindowAssigner. These panes all have their own instance of the Evictor.

Method Summary

Modifier and Type	Method and Description
Iterable<StreamRecord<O>>	getElements() Returns all elements that are currently in the buffer.
Iterable<O>	getUnpackedElements() Returns all elements that are currently in the buffer.
int	size() Returns the number of elements that are currently in the buffer.
void	snapshot(org.apache.flink.core.memory.DataOutputView out) Writes the contents of the window buffer to a DataOutputView for checkpointing.
void	storeElement(StreamRecord<T> element) Adds the element to the buffer.

Method Detail

storeElement

void storeElement(StreamRecord<T> element)
           throws Exception

Adds the element to the buffer.

Parameters:

element - The element to add.

Throws:

Exception

getElements

Iterable<StreamRecord<O>> getElements()

Returns all elements that are currently in the buffer.

getUnpackedElements

Iterable<O> getUnpackedElements()

Returns all elements that are currently in the buffer. This will unwrap the contained elements from their StreamRecord.

size

int size()

Returns the number of elements that are currently in the buffer.

snapshot

void snapshot(org.apache.flink.core.memory.DataOutputView out)
       throws IOException

Writes the contents of the window buffer to a DataOutputView for checkpointing.

Throws:

IOException