Oracle® Coherence Java API Reference
v3.5

E14977-01

com.tangosol.net.cache
Interface ConfigurableCacheMap

All Superinterfaces:
CacheMap, java.util.Map, ObservableMap
All Known Implementing Classes:
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
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.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
 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          Evict all entries from the cache that are no longer valid, and potentially prune the cache size if the cache is size-limited and its size is above the caching low water mark.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(java.lang.Object oKey)
          Evict a specified key from the cache, as if it had expired from the cache.
 void evictAll(java.util.Collection colKeys)
          Evict the specified keys from the cache, as if they had each expired from the cache.
 ConfigurableCacheMap.Entry getCacheEntry(java.lang.Object oKey)
          Locate a cache Entry in the cache based on its key.
 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 getFlushDelay()
          Determine the delay between cache flushes.
 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.
 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 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 setFlushDelay(int cMillis)
          Specify the delay between cache flushes.
 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
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, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, putAll, remove, 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(java.lang.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(java.util.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.


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

getFlushDelay

int getFlushDelay()
Determine the delay between cache flushes. A cache flush evicts entries that have expired.

This value is used by cache implementations that periodically evict entries that have expired; this value has no meaning for cache implementations that aggressively evict entries as they expire.

Returns:
the number of milliseconds between cache flushes, or zero which signifies that the cache never flushes

setFlushDelay

void setFlushDelay(int cMillis)
Specify the delay between cache flushes. A cache flush evicts entries that have expired.

This value is used by cache implementations that periodically evict entries that have expired; this value has no meaning for cache implementations that aggressively evict entries as they expire.

Parameters:
cMillis - the number of milliseconds between cache flushes, or zero to never flush

getCacheEntry

ConfigurableCacheMap.Entry getCacheEntry(java.lang.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

Oracle® Coherence Java API Reference
v3.5

E14977-01

Copyright © 2000, 2009, Oracle. All rights reserved.