com.tangosol.coherence.jcache.localcache

Class LocalCacheValue

java.lang.Object

com.tangosol.coherence.jcache.localcache.LocalCacheValue

public class LocalCacheValue
extends Object

Represents the internal Cache Entry Value with in an LocalCache.

The actual value passed to the Cache is represented in an internal format, generated by passing the value through an InternalConverter.

LocalCacheValues additionally store and provide meta information about Cache Entry Values, including information for dealing with expiry.

Since:

Coherence 12.1.3

Author:

bo 2013.12.19

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LocalCacheValue.JCacheSyntheticKind Synthetic Update

Constructor Summary

Constructors

Constructor and Description
LocalCacheValue(LocalCacheValue oldValue) Copy constructor

Method Summary

Modifier and Type	Method and Description
void	accessInternalValue(long ldtAccess, javax.cache.expiry.ExpiryPolicy policy) Access value
static LocalCacheValue	createLoadedLocalCacheValue(Object internalValue, long ldtCreation, javax.cache.expiry.ExpiryPolicy policy) Create a LocalCacheValue marked with Synthetic marker that it was loaded.
static LocalCacheValue	createLocalCacheValue(Object internalValue, long ldtCreation, javax.cache.expiry.ExpiryPolicy policy) Create a LocalCacheValue for an LocalCache entry.
Object	get() Gets the internal value (without updating the access time).
long	getAccessCount() Gets the number of times the internal value has been accessed.
long	getAccessTime() Gets the time (since the Epoc) in milliseconds since the internal value was last accessed.
long	getCreationTime() Gets the time (since the Epoc) in milliseconds since the internal value was created.
long	getExpiryTime() Gets the time (since the Epoc) in milliseconds when the Cache Entry associated with this value should be considered expired.
Object	getInternalValue() Access internal value without updating access expiry.
Object	getInternalValue(long ldtAccess) Gets the internal value with the side-effect of updating the access time to that which is specified and incrementing the access count.
long	getModificationCount() Gets the number of times the internal value has been modified (set)
long	getModificationTime() Gets the time (since the Epoc) in milliseconds since the internal value was last modified.
boolean	isExpiredAt(long ldtNow) Determines if the Cache Entry associated with this value would be expired at the specified time
boolean	isLoaded() Determine if last update to this LocalValue was a load from an external resource.
boolean	isSyntheticUpdate() determine if last update was considered synthetic
void	set(Object internalValue) Sets the internal value (without updating the modification time)
void	setExpiryTime(long ldtExpiry) Sets the time (since the Epoc) in milliseconds when the Cache Entry associated with this value should be considered expired.
LocalCacheValue	updateInternalValue(Object internalValue, long ldtModification, javax.cache.expiry.ExpiryPolicy policy) Sets the internal value with the additional side-effect of updating the modification time to that which is specified and incrementing the modification count.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalCacheValue

public LocalCacheValue(LocalCacheValue oldValue)

Copy constructor

Parameters:

oldValue - the old local cache value

Method Detail

getCreationTime

public long getCreationTime()

Gets the time (since the Epoc) in milliseconds since the internal value was created.

Returns:

time in milliseconds (since the Epoc)

getAccessTime

public long getAccessTime()

Gets the time (since the Epoc) in milliseconds since the internal value was last accessed.

Returns:

time in milliseconds (since the Epoc)

getAccessCount

public long getAccessCount()

Gets the number of times the internal value has been accessed.

Returns:

the access count

getModificationTime

public long getModificationTime()

Gets the time (since the Epoc) in milliseconds since the internal value was last modified.

Returns:

time in milliseconds (since the Epoc)

getModificationCount

public long getModificationCount()

Gets the number of times the internal value has been modified (set)

Returns:

the modification count

getExpiryTime

public long getExpiryTime()

Gets the time (since the Epoc) in milliseconds when the Cache Entry associated with this value should be considered expired.

Returns:

time in milliseconds (since the Epoc)

setExpiryTime

public void setExpiryTime(long ldtExpiry)

Sets the time (since the Epoc) in milliseconds when the Cache Entry associated with this value should be considered expired.

Parameters:

ldtExpiry - time in milliseconds (since the Epoc)

isExpiredAt

public boolean isExpiredAt(long ldtNow)

Determines if the Cache Entry associated with this value would be expired at the specified time

Parameters:

ldtNow - time in milliseconds (since the Epoc)

Returns:

true if the value would be expired at the specified time

get

public Object get()

Gets the internal value (without updating the access time).

Returns:

the internal value

set

public void set(Object internalValue)

Sets the internal value (without updating the modification time)

Parameters:

internalValue - the new internal value

getInternalValue

public Object getInternalValue(long ldtAccess)

Gets the internal value with the side-effect of updating the access time to that which is specified and incrementing the access count.

Parameters:

ldtAccess - the time when the internal value was accessed

Returns:

the internal value

getInternalValue

public Object getInternalValue()

Access internal value without updating access expiry. Added this method for accessing value to construct a CacheEntryEvent. This access should not be considered for resetting expiry for an access. With StoreByReference configured to true, this access for CacheEntryEvent could end up modifying the LocalCachedValue in the LocalCache.

Returns:

internal value

updateInternalValue

public LocalCacheValue updateInternalValue(Object internalValue,
                                           long ldtModification,
                                           javax.cache.expiry.ExpiryPolicy policy)

Sets the internal value with the additional side-effect of updating the modification time to that which is specified and incrementing the modification count.

Parameters:

internalValue - the new internal value

ldtModification - the time when the value was modified

policy - the expiry policy

Returns:

this LocalCacheValue

accessInternalValue

public void accessInternalValue(long ldtAccess,
                                javax.cache.expiry.ExpiryPolicy policy)

Access value

Parameters:

ldtAccess - the time when the value was accessed

policy - the expiry policy

createLoadedLocalCacheValue

public static LocalCacheValue createLoadedLocalCacheValue(Object internalValue,
                                                          long ldtCreation,
                                                          javax.cache.expiry.ExpiryPolicy policy)

Create a LocalCacheValue marked with Synthetic marker that it was loaded. This distinction is necessary to ensure that a just read-through entry from an external resource is not immediately written back to external resource via write-through.

Parameters:

internalValue - internal format of value of a LocalCache entry

ldtCreation - creation time

policy - expiry policy to use

Returns:

a LocalCacheValue marked as loaded via read-through

createLocalCacheValue

public static LocalCacheValue createLocalCacheValue(Object internalValue,
                                                    long ldtCreation,
                                                    javax.cache.expiry.ExpiryPolicy policy)

Create a LocalCacheValue for an LocalCache entry.

Parameters:

internalValue - internal format of value

ldtCreation - entry creation time

policy - expiry policy to use to generate expiry for the new LocalCache entry.

Returns:

LocalCache with appropriate JCache MetaInfo.

isSyntheticUpdate

public boolean isSyntheticUpdate()

determine if last update was considered synthetic

Returns:

synthetic update state

isLoaded

public boolean isLoaded()

Determine if last update to this LocalValue was a load from an external resource.

Returns:

true iff this value has not been updated since it was last loaded.