alluxio.worker.block.evictor

Class LRUEvictor

java.lang.Object

alluxio.worker.block.AbstractBlockStoreEventListener

alluxio.worker.block.evictor.AbstractEvictor

alluxio.worker.block.evictor.LRUEvictor

All Implemented Interfaces:

BlockStoreEventListener, Evictor

Direct Known Subclasses:

PartialLRUEvictor

@NotThreadSafe
public class LRUEvictor
extends AbstractEvictor

Implementation of an evictor which follows the least recently used algorithm. It discards the least recently used item based on its access.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.worker.block.evictor.Evictor

Evictor.Factory, Evictor.Mode

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<Long,Boolean>	mLRUCache Access-ordered LinkedHashMap from blockId to UNUSED_MAP_VALUE(just a placeholder to occupy the value), acts as a LRU double linked list where most recently accessed element is put at the tail while least recently accessed element is put at the head.

Fields inherited from class alluxio.worker.block.evictor.AbstractEvictor

mAllocator, mMetadataView

Constructor Summary

Constructors

Constructor and Description
LRUEvictor(BlockMetadataEvictorView view, Allocator allocator) Creates a new instance of LRUEvictor.

Method Summary

Modifier and Type	Method and Description
protected Iterator<Long>	getBlockIterator() Returns an iterator for evictor cache blocks.
void	onAccessBlock(long sessionId, long blockId) Actions when accessing a block.
void	onBlockLost(long blockId) Actions when a block is lost.
void	onCommitBlock(long sessionId, long blockId, BlockStoreLocation location) Actions when committing a temporary block to a BlockStoreLocation.
void	onRemoveBlockByClient(long sessionId, long blockId) Actions when removing an existing block.
void	onRemoveBlockByWorker(long sessionId, long blockId) Actions when removing an existing block by worker.
protected void	onRemoveBlockFromIterator(long blockId) Performs additional cleanup when a block is removed from the iterator returned by AbstractEvictor.getBlockIterator().

Methods inherited from class alluxio.worker.block.evictor.AbstractEvictor

cascadingEvict, freeSpaceWithView, freeSpaceWithView, updateBlockStoreLocation

Methods inherited from class alluxio.worker.block.AbstractBlockStoreEventListener

onAbortBlock, onMoveBlockByClient, onMoveBlockByWorker, onStorageLost

Methods inherited from class java.lang.Object

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

Field Detail

mLRUCache

protected Map<Long,Boolean> mLRUCache

Access-ordered LinkedHashMap from blockId to UNUSED_MAP_VALUE(just a placeholder to occupy the value), acts as a LRU double linked list where most recently accessed element is put at the tail while least recently accessed element is put at the head.

Constructor Detail

LRUEvictor

public LRUEvictor(BlockMetadataEvictorView view,
                  Allocator allocator)

Creates a new instance of LRUEvictor.

Parameters:

view - a view of block metadata information

allocator - an allocation policy

Method Detail

getBlockIterator

protected Iterator<Long> getBlockIterator()

Description copied from class: AbstractEvictor

Returns an iterator for evictor cache blocks. The evictor is responsible for specifying the iteration order using its own strategy. For example, LRUEvictor returns an iterator that iterates through the block ids in LRU order.

Specified by:

getBlockIterator in class AbstractEvictor

Returns:

an iterator over the ids of the blocks in the evictor cache

onAccessBlock

public void onAccessBlock(long sessionId,
                          long blockId)

Description copied from interface: BlockStoreEventListener

Actions when accessing a block.

Specified by:

onAccessBlock in interface BlockStoreEventListener

Overrides:

onAccessBlock in class AbstractBlockStoreEventListener

Parameters:

sessionId - the id of the session to access this block

blockId - the id of the block to access

onCommitBlock

public void onCommitBlock(long sessionId,
                          long blockId,
                          BlockStoreLocation location)

Description copied from interface: BlockStoreEventListener

Actions when committing a temporary block to a BlockStoreLocation.

Specified by:

onCommitBlock in interface BlockStoreEventListener

Overrides:

onCommitBlock in class AbstractBlockStoreEventListener

Parameters:

sessionId - the id of the session to commit to this block

blockId - the id of the block to commit

location - the location of the block to be committed

onRemoveBlockByClient

public void onRemoveBlockByClient(long sessionId,
                                  long blockId)

Description copied from interface: BlockStoreEventListener

Actions when removing an existing block.

Specified by:

onRemoveBlockByClient in interface BlockStoreEventListener

Overrides:

onRemoveBlockByClient in class AbstractBlockStoreEventListener

Parameters:

sessionId - the id of the session to remove this block

blockId - the id of the block to be removed

onRemoveBlockByWorker

public void onRemoveBlockByWorker(long sessionId,
                                  long blockId)

Description copied from interface: BlockStoreEventListener

Actions when removing an existing block by worker.

Specified by:

onRemoveBlockByWorker in interface BlockStoreEventListener

Overrides:

onRemoveBlockByWorker in class AbstractBlockStoreEventListener

Parameters:

sessionId - the id of the session to remove this block

blockId - the id of the block to be removed

onBlockLost

public void onBlockLost(long blockId)

Description copied from interface: BlockStoreEventListener

Actions when a block is lost.

Specified by:

onBlockLost in interface BlockStoreEventListener

Overrides:

onBlockLost in class AbstractBlockStoreEventListener

Parameters:

blockId - the id of the lost block

onRemoveBlockFromIterator

protected void onRemoveBlockFromIterator(long blockId)

Description copied from class: AbstractEvictor

Performs additional cleanup when a block is removed from the iterator returned by AbstractEvictor.getBlockIterator().

Overrides:

onRemoveBlockFromIterator in class AbstractEvictor