org.apache.ignite.cache.eviction.sorted

Class SortedEvictionPolicy<K,V>

java.lang.Object

org.apache.ignite.cache.eviction.AbstractEvictionPolicy<K,V>

org.apache.ignite.cache.eviction.sorted.SortedEvictionPolicy<K,V>

All Implemented Interfaces:

Externalizable, Serializable, EvictionPolicy<K,V>, IgniteMBeanAware

public class SortedEvictionPolicy<K,V>
extends AbstractEvictionPolicy<K,V>
implements IgniteMBeanAware

Cache eviction policy which will select the minimum cache entry for eviction.

The eviction starts in the following cases:

• The cache size becomes batchSize elements greater than the maximum size.
• The size of cache entries in bytes becomes greater than the maximum memory size. The size of cache entry calculates as sum of key size and value size.

Note:Batch eviction is enabled only if maximum memory limit isn't set (maxMemSize == 0). batchSize elements will be evicted in this case. The default batchSize value is 1.

Entries comparison based on Comparator instance if provided. Default Comparator behaviour is use cache entries keys for comparison that imposes a requirement for keys to implement Comparable interface.

User defined comparator should implement Serializable interface.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.ignite.cache.eviction.AbstractEvictionPolicy

memSize

Constructor Summary

Constructors

Constructor and Description
SortedEvictionPolicy() Constructs sorted eviction policy with all defaults.
SortedEvictionPolicy(@Nullable Comparator<EvictableEntry<K,V>> comp) Constructs sorted eviction policy with given maximum size and given entry comparator.
SortedEvictionPolicy(int max) Constructs sorted eviction policy with maximum size.
SortedEvictionPolicy(int max, @Nullable Comparator<EvictableEntry<K,V>> comp) Constructs sorted eviction policy with given maximum size and given entry comparator.
SortedEvictionPolicy(int max, int batchSize, @Nullable Comparator<EvictableEntry<K,V>> comp) Constructs sorted eviction policy with given maximum size, eviction batch size and entries comparator.

Method Summary

Modifier and Type	Method and Description
int	getCurrentSize()
Object	getMBean()
Collection<EvictableEntry<K,V>>	queue() Gets read-only view of backed queue in proper order.
void	readExternal(ObjectInput in)
protected boolean	removeMeta(Object meta) Removes holder from backed queue and marks holder as removed.
SortedEvictionPolicy<K,V>	setBatchSize(int batchSize) Sets batch size.
SortedEvictionPolicy<K,V>	setMaxMemorySize(long maxMemSize) Sets maximum allowed cache size in bytes.
SortedEvictionPolicy<K,V>	setMaxSize(int max) Sets maximum allowed size of cache before entry will start getting evicted.
protected int	shrink0() Tries to remove one item from queue.
protected boolean	touch(EvictableEntry<K,V> entry)
void	writeExternal(ObjectOutput out)

Methods inherited from class org.apache.ignite.cache.eviction.AbstractEvictionPolicy

getBatchSize, getCurrentMemorySize, getMaxMemorySize, getMaxSize, onEntryAccessed, shrink

Methods inherited from class java.lang.Object

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

Constructor Detail

SortedEvictionPolicy

public SortedEvictionPolicy()

Constructs sorted eviction policy with all defaults.

SortedEvictionPolicy

public SortedEvictionPolicy(int max)

Constructs sorted eviction policy with maximum size.

Parameters:

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

SortedEvictionPolicy

public SortedEvictionPolicy(int max,
                            @Nullable
                            @Nullable Comparator<EvictableEntry<K,V>> comp)

Constructs sorted eviction policy with given maximum size and given entry comparator.

Parameters:

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

comp - Entries comparator.

SortedEvictionPolicy

public SortedEvictionPolicy(int max,
                            int batchSize,
                            @Nullable
                            @Nullable Comparator<EvictableEntry<K,V>> comp)

Constructs sorted eviction policy with given maximum size, eviction batch size and entries comparator.

Parameters:

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

batchSize - Batch size.

comp - Entries comparator.

SortedEvictionPolicy

public SortedEvictionPolicy(@Nullable
                            @Nullable Comparator<EvictableEntry<K,V>> comp)

Constructs sorted eviction policy with given maximum size and given entry comparator.

Parameters:

comp - Entries comparator.

Method Detail

setMaxMemorySize

public SortedEvictionPolicy<K,V> setMaxMemorySize(long maxMemSize)

Sets maximum allowed cache size in bytes.

Overrides:

setMaxMemorySize in class AbstractEvictionPolicy<K,V>

Returns:

this for chaining.

setMaxSize

public SortedEvictionPolicy<K,V> setMaxSize(int max)

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

Overrides:

setMaxSize in class AbstractEvictionPolicy<K,V>

Parameters:

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

Returns:

this for chaining.

setBatchSize

public SortedEvictionPolicy<K,V> setBatchSize(int batchSize)

Sets batch size.

Overrides:

setBatchSize in class AbstractEvictionPolicy<K,V>

Parameters:

batchSize - Batch size.

Returns:

this for chaining.

queue

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

Gets read-only view of backed queue in proper order.

Returns:

Read-only view of backed queue.

touch

protected boolean touch(EvictableEntry<K,V> entry)

Specified by:

touch in class AbstractEvictionPolicy<K,V>

Parameters:

entry - Entry to touch.

Returns:

True if backed queue has been changed by this call.

getCurrentSize

public int getCurrentSize()

Specified by:

getCurrentSize in class AbstractEvictionPolicy<K,V>

Returns:

Size of the container with trackable entries.

shrink0

protected int shrink0()

Tries to remove one item from queue.

Specified by:

shrink0 in class AbstractEvictionPolicy<K,V>

Returns:

number of bytes that was free. -1 if queue is empty.

getMBean

public Object getMBean()

Specified by:

getMBean in interface IgniteMBeanAware

Returns:

MBean for this object.

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class AbstractEvictionPolicy<K,V>

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class AbstractEvictionPolicy<K,V>

Throws:

IOException

ClassNotFoundException

removeMeta

protected boolean removeMeta(Object meta)

Removes holder from backed queue and marks holder as removed.

Specified by:

removeMeta in class AbstractEvictionPolicy<K,V>

Parameters:

meta - Holder.

Returns:

True if meta was successfully removed from the container.