HsDataView (Flink : Runtime 1.19.3-cp2 API)

All Known Subinterfaces:

HsSubpartitionFileReader

All Known Implementing Classes:

HsSubpartitionConsumerMemoryDataManager, HsSubpartitionFileReaderImpl
```
public interface HsDataView
```
A view for HsSubpartitionConsumer to find out what data exists in memory or disk and polling the data.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Optional<ResultSubpartition.BufferAndBacklog>`	`consumeBuffer(int nextBufferToConsume, Collection<Buffer> buffersToRecycle)`	Try to consume next buffer.
`int`	`getBacklog()`	Get the number of buffers whose `Buffer.DataType` is buffer.
`Buffer.DataType`	`peekNextToConsumeDataType(int nextBufferToConsume, Collection<Buffer> buffersToRecycle)`	Get dataType of next buffer to consume.
`void`	`releaseDataView()`	Release this `HsDataView` when related subpartition view is releasing.

- Method Detail
  - consumeBuffer
```
Optional<ResultSubpartition.BufferAndBacklog> consumeBuffer(int nextBufferToConsume,
                                                            Collection<Buffer> buffersToRecycle)
                                                     throws Throwable
```
    Try to consume next buffer.
    Only invoked by consumer thread.
    
    Parameters:
    
    nextBufferToConsume - next buffer index to consume.
    
    buffersToRecycle - buffers to recycle if needed.
    
    Returns:
    
    If the target buffer does exist, return buffer and next buffer's backlog, otherwise return Optional.empty().
    
    Throws:
    
    Throwable
  - peekNextToConsumeDataType
```
Buffer.DataType peekNextToConsumeDataType(int nextBufferToConsume,
                                          Collection<Buffer> buffersToRecycle)
```
    Get dataType of next buffer to consume.
    
    Parameters:
    
    nextBufferToConsume - next buffer index to consume
    
    buffersToRecycle - buffers to recycle if needed.
    
    Returns:
    
    next buffer's dataType. If not found in memory, return Buffer.DataType.NONE.
  - getBacklog
```
int getBacklog()
```
    Get the number of buffers whose Buffer.DataType is buffer.
    
    Returns:
    
    backlog of this view's corresponding subpartition.
  - releaseDataView
```
void releaseDataView()
```
    Release this HsDataView when related subpartition view is releasing.