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com.tangosol.net.cache
Class OldCache.Entry

java.lang.Object
com.tangosol.util.Base
com.tangosol.util.SafeHashMap.Entry
com.tangosol.net.cache.OldCache.Entry

All Implemented Interfaces:

ConfigurableCacheMap.Entry, java.io.Serializable, java.lang.Cloneable, java.util.Map.Entry

Direct Known Subclasses:

LocalCache.Entry

Enclosing class:

OldCache

public class OldCache.Entry

extends SafeHashMap.Entry

implements ConfigurableCacheMap.Entry

A holder for a cached value.

Author:

cp 2001.04.19

Field Summary

Fields inherited from class com.tangosol.util.SafeHashMap.Entry

m_eNext, m_nHash, m_oKey, m_oValue

Constructor Summary

OldCache.Entry()
Construct the cacheable entry that holds the cached value.

Method Summary

protected int	calculateUnits(java.lang.Object oValue) Calculate a cache cost for the specified object.
protected void	copyFrom(SafeHashMap.Entry entry) Copy this Entry's information from another Entry.
protected void	discard() Called to inform the Entry that it is no longer used.
long	getCreatedMillis() Determine when the cache entry was created.
long	getExpiryMillis() Determine when the cache entry will expire, if ever.
long	getLastTouchMillis() Determine when the cache entry was last touched.
int	getPriority() Calculate a cache priority.
int	getTouchCount() Determine the number of times that the cache entry has been touched.
int	getUnits() Determine the number of cache units used by this Entry.
protected boolean	isDiscarded() Determine if this entry has already been discarded from the cache.
protected boolean	isEvictable() Determine if this entry has been marked as being evictable.
boolean	isExpired() Determine if the cache entry has expired.
protected void	onAdd() This method is invoked when the containing Map has actually added this Entry to itself.
protected void	registerExpiry(long lMillis) Register (or unregister or replace the registration of) this entry for expiry.
protected void	resetTouchCount() Reset the number of times that the cache entry has been touched.
protected void	scheduleExpiry() Reschedule the cache entry expiration.
protected void	setEvictable(boolean fEvict) Specify that this entry is evictable or not.
void	setExpiryMillis(long lMillis) Specify when the cache entry will expire, or disable expiry.
void	setUnits(int cUnits) Specify the number of cache units used by this Entry.
java.lang.Object	setValue(java.lang.Object oValue) Update the cached value.
java.lang.String	toString() Render the cache entry as a String.
void	touch() Called each time the entry is accessed or modified.

Methods inherited from class com.tangosol.util.SafeHashMap.Entry

clone, equals, getKey, getValue, hashCode

Methods inherited from interface java.util.Map.Entry

equals, getKey, getValue, hashCode

Constructor Detail

OldCache.Entry

public OldCache.Entry()

Construct the cacheable entry that holds the cached value.

Method Detail

onAdd

protected void onAdd()

This method is invoked when the containing Map has actually added this Entry to itself.

Overrides:

onAdd in class SafeHashMap.Entry

setValue

public java.lang.Object setValue(java.lang.Object oValue)

Update the cached value.

Specified by:

setValue in interface java.util.Map.Entry

Overrides:

setValue in class SafeHashMap.Entry

Parameters:

oValue - the new value to cache

Returns:

the old cache value

copyFrom

protected void copyFrom(SafeHashMap.Entry entry)

Copy this Entry's information from another Entry. Sub-classes must implement this method if they add any additional fields.

Overrides:

copyFrom in class SafeHashMap.Entry

Parameters:

entry - the entry to copy from

getPriority

public int getPriority()

Calculate a cache priority.

Returns:

a value between 0 and 10, 0 being the highest priority

getCreatedMillis

public long getCreatedMillis()

Determine when the cache entry was created.

Returns:

the date/time value, in millis, when the entry was created

touch

public void touch()

Called each time the entry is accessed or modified.

Specified by:

touch in interface ConfigurableCacheMap.Entry

getLastTouchMillis

public long getLastTouchMillis()

Determine when the cache entry was last touched.

Specified by:

getLastTouchMillis in interface ConfigurableCacheMap.Entry

Returns:

the date/time value, in millis, when the entry was most recently touched

getTouchCount

public int getTouchCount()

Determine the number of times that the cache entry has been touched.

Specified by:

getTouchCount in interface ConfigurableCacheMap.Entry

Returns:

the number of times that the cache entry has been touched

resetTouchCount

protected void resetTouchCount()

Reset the number of times that the cache entry has been touched. The touch count does not get reset to zero, but rather to a fraction of its former self; this prevents long lived items from gaining an unassailable advantage in the eviction process.

Since:

Coherence 3.5

getExpiryMillis

public long getExpiryMillis()

Determine when the cache entry will expire, if ever.

Specified by:

getExpiryMillis in interface ConfigurableCacheMap.Entry

Returns:

the date/time value, in millis, when the entry will (or did) expire; zero indicates no expiry

setExpiryMillis

public void setExpiryMillis(long lMillis)

Specify when the cache entry will expire, or disable expiry. Note that if the cache is configured for automatic expiry, each subsequent update to this cache entry will reschedule the expiry time.

Specified by:

setExpiryMillis in interface ConfigurableCacheMap.Entry

Parameters:

lMillis - pass the date/time value, in millis, for when the entry will expire, or pass zero to disable automatic expiry

registerExpiry

protected void registerExpiry(long lMillis)

Register (or unregister or replace the registration of) this entry for expiry.

Parameters:

lMillis - the date/time value for when the entry will expire; 0 is passed to indicate that the entry needs to be removed from the items queued for expiry

isExpired

public boolean isExpired()

Determine if the cache entry has expired.

Returns:

true if the cache entry was subject to automatic expiry and the current time is greater than the entry's expiry time

scheduleExpiry

protected void scheduleExpiry()

Reschedule the cache entry expiration.

discard

protected void discard()

Called to inform the Entry that it is no longer used.

isDiscarded

protected boolean isDiscarded()

Determine if this entry has already been discarded from the cache.

Returns:

true if this entry has been discarded

calculateUnits

protected int calculateUnits(java.lang.Object oValue)

Calculate a cache cost for the specified object.

The default implementation uses the unit calculator type of the containing cache.

Parameters:

oValue - the cache value to evaluate for unit cost

Returns:

an integer value 0 or greater, with a larger value signifying a higher cost

getUnits

public int getUnits()

Determine the number of cache units used by this Entry.

Specified by:

getUnits in interface ConfigurableCacheMap.Entry

Returns:

an integer value 0 or greater, with a larger value signifying a higher cost; -1 implies that the Entry has been discarded

setUnits

public void setUnits(int cUnits)

Specify the number of cache units used by this Entry.

Specified by:

setUnits in interface ConfigurableCacheMap.Entry

Parameters:

cUnits - an integer value 0 or greater, with a larger value signifying a higher cost

isEvictable

protected boolean isEvictable()

Determine if this entry has been marked as being evictable.

Returns:

true if this entry is evictable

Since:

Coherence 3.5

setEvictable

protected void setEvictable(boolean fEvict)

Specify that this entry is evictable or not.

Parameters:

fEvict - true to specify that this entry is evictable, such as when it is selected for deferred eviction, and false to specify that it is no longer evictable

Since:

Coherence 3.5

toString

public java.lang.String toString()

Render the cache entry as a String.

Overrides:

toString in class SafeHashMap.Entry

Returns:

the details about this Entry

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