org.gridgain.grid.cache.eviction.fifo
Class GridCacheFifoEvictionPolicy<K,V>

java.lang.Object
  org.gridgain.grid.cache.eviction.fifo.GridCacheFifoEvictionPolicy<K,V>

All Implemented Interfaces:

GridCacheFifoEvictionPolicyMBean, GridCacheEvictionPolicy<K,V>

public class GridCacheFifoEvictionPolicy<K,V>
extends Object
implements GridCacheEvictionPolicy<K,V>, GridCacheFifoEvictionPolicyMBean

Eviction policy based on First In First Out (FIFO) algorithm. This implementation is very efficient since it is lock-free and does not create any additional table-like data structures. The FIFO ordering information is maintained by attaching ordering metadata to cache entries.

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Constructor Summary

GridCacheFifoEvictionPolicy()
Constructs LRU eviction policy with all defaults.

GridCacheFifoEvictionPolicy(int max)
Constructs FIFO eviction policy with maximum size.

GridCacheFifoEvictionPolicy(int max, boolean allowEmptyEntries)
Constructs FIFO eviction policy with maximum size and allow empty entries flag specified.

Method Summary

int	getCurrentSize() Gets current queue size.
int	getMaxSize() Gets maximum allowed size of cache before entry will start getting evicted.
String	getMetaAttributeName() Gets name of metadata attribute used to store eviction policy data.
boolean	isAllowEmptyEntries() Gets flag indicating whether empty entries (entries with null values) are allowed.
void	onEntryAccessed(boolean rmv, GridCacheEntry<K,V> entry) Callback for whenever entry is accessed.
Collection<GridCacheEntry<K,V>>	queue() Gets read-only view on internal FIFO queue in proper order.
void	setAllowEmptyEntries(boolean allowEmptyEntries) Sets flag that allows empty entries (entries with null values) to be stored in cache.
void	setMaxSize(int max) Sets maximum allowed size of cache before entry will start getting evicted.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

GridCacheFifoEvictionPolicy

public GridCacheFifoEvictionPolicy()

Constructs LRU eviction policy with all defaults.

GridCacheFifoEvictionPolicy

public GridCacheFifoEvictionPolicy(int max)

Constructs FIFO eviction policy with maximum size. Empty entries are allowed.

Parameters:

max - Maximum allowed size of cache before entry will start getting evicted.

GridCacheFifoEvictionPolicy

public GridCacheFifoEvictionPolicy(int max,
                                   boolean allowEmptyEntries)

Constructs FIFO eviction policy with maximum size and allow empty entries flag specified.

Parameters:

max - Maximum allowed size of cache before entry will start getting evicted.

allowEmptyEntries - If false, false empty entries will be evicted immediately.

Method Detail

getMaxSize

public int getMaxSize()

Gets maximum allowed size of cache before entry will start getting evicted.

Specified by:

getMaxSize in interface GridCacheFifoEvictionPolicyMBean

Returns:

Maximum allowed size of cache before entry will start getting evicted.

setMaxSize

public void setMaxSize(int max)

Sets maximum allowed size of cache before entry will start getting evicted.

Specified by:

setMaxSize in interface GridCacheFifoEvictionPolicyMBean

Parameters:

max - Maximum allowed size of cache before entry will start getting evicted.

isAllowEmptyEntries

public boolean isAllowEmptyEntries()

Gets flag indicating whether empty entries (entries with null values) are allowed.

Specified by:

isAllowEmptyEntries in interface GridCacheFifoEvictionPolicyMBean

Returns:

True if empty entries are allowed, false otherwise.

setAllowEmptyEntries

public void setAllowEmptyEntries(boolean allowEmptyEntries)

Sets flag that allows empty entries (entries with null values) to be stored in cache.

Specified by:

setAllowEmptyEntries in interface GridCacheFifoEvictionPolicyMBean

Parameters:

allowEmptyEntries - If false, empty entries will be evicted immediately.

getCurrentSize

public int getCurrentSize()

Gets current queue size.

Specified by:

getCurrentSize in interface GridCacheFifoEvictionPolicyMBean

Returns:

Current queue size.

getMetaAttributeName

public String getMetaAttributeName()

Gets name of metadata attribute used to store eviction policy data.

Specified by:

getMetaAttributeName in interface GridCacheFifoEvictionPolicyMBean

Returns:

Name of metadata attribute used to store eviction policy data.

queue

public Collection<GridCacheEntry<K,V>> queue()

Gets read-only view on internal FIFO queue in proper order.

Returns:

Read-only view ono internal 'FIFO' queue.

onEntryAccessed

public void onEntryAccessed(boolean rmv,
                            GridCacheEntry<K,V> entry)

Callback for whenever entry is accessed.

Specified by:

onEntryAccessed in interface GridCacheEvictionPolicy<K,V>

Parameters:

rmv - True if entry has been removed, false otherwise.

entry - Accessed entry.

toString

public String toString()

Overrides:

toString in class Object