com.tangosol.net.cache

Interface ConfigurableCacheMap

All Superinterfaces:

CacheMap, Map, ObservableMap

All Known Implementing Classes:

BlindCompactSerializationCache, CompactSerializationCache, LocalCache, ObservableSplittingBackingCache, OldCache, SerializationCache

public interface ConfigurableCacheMap
extends CacheMap

An extension to the CacheMap interface that supports runtime configuration and monitoring of various caching properties.

Since:

Coherence 3.5

Author:

cp 2009-01-13

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	ConfigurableCacheMap.Entry A cache Entry carries information additional to the base Map Entry in order to support eviction and expiry.
static interface	ConfigurableCacheMap.EvictionApprover EvictionApprover is used to approve the eviction of an entry from the underlying ConfigurableCacheMap.
static interface	ConfigurableCacheMap.EvictionPolicy An eviction policy is an object that the cache provides with access information, and when requested, the eviction policy selects and evicts entries from the cache.
static interface	ConfigurableCacheMap.UnitCalculator A unit calculator is an object that can calculate the cost of caching an object.

Field Summary

Fields inherited from interface com.tangosol.net.cache.CacheMap

EXPIRY_DEFAULT, EXPIRY_NEVER

Method Summary

Modifier and Type	Method and Description
void	evict() Evict all entries from the cache that are no longer valid, and potentially prune the cache size if the cache is size-limited and its size is above the caching low water mark.
void	evict(Object oKey) Evict a specified key from the cache, as if it had expired from the cache.
void	evictAll(Collection colKeys) Evict the specified keys from the cache, as if they had each expired from the cache.
ConfigurableCacheMap.Entry	getCacheEntry(Object oKey) Locate a cache Entry in the cache based on its key.
ConfigurableCacheMap.EvictionApprover	getEvictionApprover() Obtain the registered EvictionApprover.
ConfigurableCacheMap.EvictionPolicy	getEvictionPolicy() Obtain the current EvictionPolicy used by the cache.
int	getExpiryDelay() Determine the default "time to live" for each individual cache entry.
int	getHighUnits() Determine the limit of the cache size in units.
int	getLowUnits() Determine the point to which the cache will shrink when it prunes.
long	getNextExpiryTime() Determine the next expiry time for the cache entries.
ConfigurableCacheMap.UnitCalculator	getUnitCalculator() Obtain the current UnitCalculator used by the cache.
int	getUnitFactor() Determine the factor by which the Units, LowUnits and HighUnits properties are adjusted.
int	getUnits() Determine the number of units that the cache currently stores.
void	setEvictionApprover(ConfigurableCacheMap.EvictionApprover approver) Set the EvictionApprover for this ConfigurableCacheMap.
void	setEvictionPolicy(ConfigurableCacheMap.EvictionPolicy policy) Set the EvictionPolicy for the cache to use.
void	setExpiryDelay(int cMillis) Specify the default "time to live" for cache entries.
void	setHighUnits(int cMax) Update the maximum size of the cache in units.
void	setLowUnits(int cUnits) Specify the point to which the cache will shrink when it prunes.
void	setUnitCalculator(ConfigurableCacheMap.UnitCalculator calculator) Set the UnitCalculator for the cache to use.
void	setUnitFactor(int nFactor) Determine the factor by which the Units, LowUnits and HighUnits properties are adjusted.

Methods inherited from interface com.tangosol.net.cache.CacheMap

forEach, getAll, put, put

Methods inherited from interface com.tangosol.util.ObservableMap

addMapListener, addMapListener, addMapListener, removeMapListener, removeMapListener, removeMapListener

Methods inherited from interface java.util.Map

clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

Method Detail

getUnits

int getUnits()

Determine the number of units that the cache currently stores.

Note: It is expected that the return type will be widened to a long in Coherence 4.

Returns:

the current size of the cache in units

getHighUnits

int getHighUnits()

Determine the limit of the cache size in units. The cache will prune itself automatically once it reaches its maximum unit level. This is often referred to as the "high water mark" of the cache.

Note: It is expected that the return type will be widened to a long in Coherence 4.

Returns:

the limit of the cache size in units

setHighUnits

void setHighUnits(int cMax)

Update the maximum size of the cache in units. This is often referred to as the "high water mark" of the cache.

Note: It is expected that the parameter will be widened to a long in Coherence 4.

Parameters:

cMax - the new maximum size of the cache, in units

getLowUnits

int getLowUnits()

Determine the point to which the cache will shrink when it prunes. This is often referred to as a "low water mark" of the cache. If the cache incrementally prunes, then this setting will have no effect.

Note: It is expected that the parameter will be widened to a long in Coherence 4.

Returns:

the number of units that the cache prunes to

setLowUnits

void setLowUnits(int cUnits)

Specify the point to which the cache will shrink when it prunes. This is often referred to as a "low water mark" of the cache.

Note: It is expected that the parameter will be widened to a long in Coherence 4.

Parameters:

cUnits - the number of units that the cache prunes to

getUnitFactor

int getUnitFactor()

Determine the factor by which the Units, LowUnits and HighUnits properties are adjusted. Using a binary unit calculator, for example, the factor 1048576 could be used to count megabytes instead of bytes.

Note: This property exists only to avoid changing the type of the units, low units and high units properties from 32-bit values to 64-bit values. It is expected that the parameter will be dropped in Coherence 4.

Returns:

the units factor; the default is 1

setUnitFactor

void setUnitFactor(int nFactor)

Determine the factor by which the Units, LowUnits and HighUnits properties are adjusted. Using a binary unit calculator, for example, the factor 1048576 could be used to count megabytes instead of bytes.

Note: This property exists only to avoid changing the type of the units, low units and high units properties from 32-bit values to 64-bit values. It is expected that the parameter will be dropped in Coherence 4.

Parameters:

nFactor - the units factor; the default is 1

evict

void evict(Object oKey)

Evict a specified key from the cache, as if it had expired from the cache. If the key is not in the cache, then the method has no effect.

Parameters:

oKey - the key to evict from the cache

evictAll

void evictAll(Collection colKeys)

Evict the specified keys from the cache, as if they had each expired from the cache.

The result of this method is defined to be semantically the same as the following implementation:

 for (Iterator iter = colKeys.iterator(); iter.hasNext(); )
     {
     Object oKey = iter.next();
     evict(oKey);
     }
 

Parameters:

colKeys - a collection of keys to evict from the cache

evict

void evict()

Evict all entries from the cache that are no longer valid, and potentially prune the cache size if the cache is size-limited and its size is above the caching low water mark.

getEvictionApprover

ConfigurableCacheMap.EvictionApprover getEvictionApprover()

Obtain the registered EvictionApprover.

Returns:

the EvictionApprover (could be null)

setEvictionApprover

void setEvictionApprover(ConfigurableCacheMap.EvictionApprover approver)

Set the EvictionApprover for this ConfigurableCacheMap.

Parameters:

approver - the EvictionApprover

getExpiryDelay

int getExpiryDelay()

Determine the default "time to live" for each individual cache entry.

Returns:

the number of milliseconds that a cache entry value will live, or zero if cache entries are never automatically expired

setExpiryDelay

void setExpiryDelay(int cMillis)

Specify the default "time to live" for cache entries. This does not affect the already-scheduled expiry of existing entries.

Parameters:

cMillis - the number of milliseconds that cache entries will live, or zero to disable automatic expiry

getNextExpiryTime

long getNextExpiryTime()

Determine the next expiry time for the cache entries. This value is supposed to be used only by the "active" expiry algorithms, so for implementations that choose to return the value of zero the entries will be evicted as with pre-existing "passive" expiry approach.

Returns:

the earliest time (using the SafeClock) that one or more cache entries will expire or zero if the cache is empty, its entries never expire or the implementation chooses to avoid the pro-active eviction

getCacheEntry

ConfigurableCacheMap.Entry getCacheEntry(Object oKey)

Locate a cache Entry in the cache based on its key.

Parameters:

oKey - the key object to search for

Returns:

the Entry or null

getEvictionPolicy

ConfigurableCacheMap.EvictionPolicy getEvictionPolicy()

Obtain the current EvictionPolicy used by the cache.

Returns:

the EvictionPolicy used by the cache

setEvictionPolicy

void setEvictionPolicy(ConfigurableCacheMap.EvictionPolicy policy)

Set the EvictionPolicy for the cache to use.

Parameters:

policy - an EvictionPolicy

getUnitCalculator

ConfigurableCacheMap.UnitCalculator getUnitCalculator()

Obtain the current UnitCalculator used by the cache.

Returns:

the UnitCalculator used by the cache

setUnitCalculator

void setUnitCalculator(ConfigurableCacheMap.UnitCalculator calculator)

Set the UnitCalculator for the cache to use.

Parameters:

calculator - a UnitCalculator