org.apache.flink.runtime.io.disk

Class BatchShuffleReadBufferPool

java.lang.Object

org.apache.flink.runtime.io.disk.BatchShuffleReadBufferPool

public class BatchShuffleReadBufferPool
extends Object

A fixed-size MemorySegment pool used by batch shuffle for shuffle data read (currently only used by sort-merge blocking shuffle).

Field Summary

Fields

Modifier and Type	Field and Description
static int	NUM_BYTES_PER_REQUEST Memory size in bytes can be allocated from this buffer pool for a single request (4M is for better sequential read).

Constructor Summary

Constructors

Constructor and Description
BatchShuffleReadBufferPool(long totalBytes, int bufferSize)

Method Summary

Modifier and Type	Method and Description
void	destroy() Destroys this buffer pool and after which, no buffer can be allocated any more.
int	getAvailableBuffers()
int	getAverageBuffersPerRequester()
int	getBufferSize()
long	getLastBufferOperationTimestamp()
int	getMaxConcurrentRequests()
int	getNumBuffersPerRequest()
int	getNumTotalBuffers()
void	initialize() Initializes this buffer pool which allocates all the buffers.
boolean	isDestroyed()
void	recycle(Collection<MemorySegment> segments) Recycles a collection of buffers to this buffer pool.
void	recycle(MemorySegment segment) Recycles the target buffer to this buffer pool.
void	registerRequester(Object requester)
List<MemorySegment>	requestBuffers() Requests a collection of buffers (determined by numBuffersPerRequest) from this buffer pool.
void	unregisterRequester(Object requester)

Methods inherited from class java.lang.Object

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

Field Detail

NUM_BYTES_PER_REQUEST

public static final int NUM_BYTES_PER_REQUEST

Memory size in bytes can be allocated from this buffer pool for a single request (4M is for better sequential read).

See Also:

Constant Field Values

Constructor Detail

BatchShuffleReadBufferPool

public BatchShuffleReadBufferPool(long totalBytes,
                                  int bufferSize)

Method Detail

getNumTotalBuffers

@VisibleForTesting
public int getNumTotalBuffers()

getAvailableBuffers

@VisibleForTesting
public int getAvailableBuffers()

getNumBuffersPerRequest

public int getNumBuffersPerRequest()

getMaxConcurrentRequests

public int getMaxConcurrentRequests()

getBufferSize

public int getBufferSize()

initialize

public void initialize()

Initializes this buffer pool which allocates all the buffers.

registerRequester

public void registerRequester(Object requester)

unregisterRequester

public void unregisterRequester(Object requester)

getAverageBuffersPerRequester

public int getAverageBuffersPerRequester()

requestBuffers

public List<MemorySegment> requestBuffers()
                                   throws Exception

Requests a collection of buffers (determined by numBuffersPerRequest) from this buffer pool.

Throws:

Exception

recycle

public void recycle(MemorySegment segment)

Recycles the target buffer to this buffer pool. This method should never throw any exception.

recycle

public void recycle(Collection<MemorySegment> segments)

Recycles a collection of buffers to this buffer pool. This method should never throw any exception.

getLastBufferOperationTimestamp

public long getLastBufferOperationTimestamp()

destroy

public void destroy()

Destroys this buffer pool and after which, no buffer can be allocated any more.

isDestroyed

public boolean isDestroyed()