oracle.ias.cache
Class Cache

java.lang.Object
  oracle.ias.cache.Cache

public class Cache

extends java.lang.Object

The Cache class provides APIs for cache administration tasks, such as initialization, termination and monitoring.

Since:

2.0.0

See Also:

CacheAttributes, CacheObjectInfo

Constructor Summary

Cache()

 

Method Summary
static void	close()           marks the cache as " not ready" and shutdown the cache.
static void	destroy()           globally destroys all the objects in the cache system, includes all processes, memory and disk.
static void	destroy(boolean localOnly)           globally destroys all the objects in the cache memory and disk.
static void	dump()           dumps all the objects in cache to the log file.
static CacheHostInfo[]	getActiveHostInfo()           returns an array of CacheHostInfo objects, one for each active member of the cache system
static CacheAttributes	getAttributes()           returns the attributes currently associated with the cache.
static java.lang.String	getCacheAddress()           returns the String representation of the address currently being used by this instance of the cache, or null if the cache is not on the network.
static oracle.ias.cache.CacheAddress	getCacheAddressObject()           returns the Object representation of the address of the current instance of the cache, or null if the cache is not on the network.
static int	getCacheId()           returns the global cache Id in a distributed cache system.
static CacheLogger	getCacheLogger()           returns a reference to the CacheLogger currently being used by the cache
static long	getCacheSize()           returns an estimate of the number of bytes consumed by objects in the memory cache.
static long	getDistributedDiskCacheSize()           returns the number of bytes consumed by objects in the distributed disk cache.
static long	getLocalDiskCacheSize()           returns the number of bytes consumed by objects in the local disk cache.
static int	getObjectCount()           returns the current count of objects in the cache.
static java.lang.String	getVersion()           GetVersion returns the current version of the cache.
static void	init(CacheAttributes attr)           initializes the cache.
static void	invalidate()           globally invalidates all the objects in the cache system, includes all processes, memory and disk.
static void	invalidate(boolean localOnly)           globally invalidates all the objects in the cache memory and disk.
static boolean	isDistributed()           returns true if the cache is currently in distributed mode, that it is distributing updates and invalidates within the site, false if all cache actions are local to the process only.
static boolean	isReady()           returns true if the cache has been initialized, false otherwise.
static java.util.Enumeration	listCacheObjects()           returns an Enumeration of CacheObjectInfo objects describing the objects in all regions in the cache.
static java.util.Enumeration	listCacheObjects(java.lang.String region)           returns an Enumeration of CacheObjectInfo objects describing the objects in specified region in the cache.
static void	open()           reads the configuration files and establishs the Java caching system in the process.
static void	open(java.lang.String configFile)           reads the configuration files and establishs the Java caching system in the process.
static void	resetAttributes(CacheAttributes attr)           allows some cache attributes to be reset while the cache is running.
static void	setLogSeverity(int severity)           sets the log severity of the cache system.
static void	updateStats()           aggregate the statics for the cache.

 

Methods inherited from class java.lang.Object

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

 

Constructor Detail

Cache

public Cache()

open

public static void open()
                 throws CacheException

reads the configuration files and establishs the Java caching system in the process. During the initialization, a hash table is created for storing cached objects, the cache management and message receive threads are started, the metadata is loaded from the disk cache and the cache is registered with the group protocol layer if the cache is distributed. This method should only be called once for each process.

Throws:

CacheException - if the open() fails.

open

public static void open(java.lang.String configFile)
                 throws CacheException

reads the configuration files and establishs the Java caching system in the process. During the initialization, a hash table is created for storing cached objects, the cache management and message receive threads are started, the metadata is loaded from the disk cache and the cache is registered with the group protocol layer if the cache is distributed. This method should only be called once for each process.

Parameters:

configFile - the name of the configuration file to read the configuration information from

Throws:

CacheException - if the open() fails.

init

public static void init(CacheAttributes attr)
                 throws CacheException

initializes the cache. This includes allocating space for metadata and starting service threads. The attributes parameter contains configuration information to initialize the cache system.

Parameters:

attr - CacheAttributes which has the cache configuration information.

Throws:

CacheException - if the init() fails.

Since:

2.0.0

close

public static void close()

marks the cache as " not ready" and shutdown the cache. Marking the cache as "not ready" will prevent any threads from accessing the cache during shutdown. If the cache is distributed, close will unregister with the distributed caching system. Close should be called as part of process termination.

Since:

2.0.0

getAttributes

public static CacheAttributes getAttributes()
                                     throws CacheNotAvailableException

returns the attributes currently associated with the cache.

Returns:

a CacheAttributes object with all the configuration information.

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.0.0

getObjectCount

public static int getObjectCount()
                          throws CacheNotAvailableException

returns the current count of objects in the cache.

Returns:

the current count of objects in the cache

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.1.1

getCacheSize

public static long getCacheSize()
                         throws CacheNotAvailableException

returns an estimate of the number of bytes consumed by objects in the memory cache. The accuracy of this value depends on the accuracy of the size attribute set by the user for each object in the cache. If the cache configuration parameter "maxSize" has not been set, the cache size is not maintained so this method will always return 0.

Returns:

an estimate of the number of bytes consumed by objects in the cache

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.1.1

getLocalDiskCacheSize

public static long getLocalDiskCacheSize()
                                  throws CacheNotAvailableException

returns the number of bytes consumed by objects in the local disk cache.

If the disk cache is not configured, this method will return 0.

Returns:

the number of bytes consumed by objects in the local disk cache

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.1.1

getDistributedDiskCacheSize

public static long getDistributedDiskCacheSize()
                                        throws CacheNotAvailableException

returns the number of bytes consumed by objects in the distributed disk cache. If the disk cache is not configured or the cache is not distributed, this method will return 0.

Returns:

the number of bytes consumed by objects in the distributed disk cache

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.1.1

resetAttributes

public static void resetAttributes(CacheAttributes attr)
                            throws CacheNotAvailableException

allows some cache attributes to be reset while the cache is running. The following attributes can be reset: maxObjects, maxSize, diskSize, cleanInterval and logSeverity.

Parameters:

attr - CacheAttributes which has the cache configuration information.

Throws:

CacheNotAvailableException - if the cache has not been intialized.

Since:

2.1.1

invalidate

public static void invalidate()
                       throws CacheException

globally invalidates all the objects in the cache system, includes all processes, memory and disk.

Throws:

CacheException - if any cache error occurs

Since:

2.0.0

invalidate

public static void invalidate(boolean localOnly)
                       throws CacheException

globally invalidates all the objects in the cache memory and disk.

Parameters:

localOnly - if true only objects in the local cache are invalidated

Throws:

CacheException - if any cache error occurs

Since:

9.0.4

destroy

public static void destroy()
                    throws CacheException

globally destroys all the objects in the cache system, includes all processes, memory and disk.

Throws:

CacheException - if any cache error occurs

Since:

2.0.0

destroy

public static void destroy(boolean localOnly)
                    throws CacheException

globally destroys all the objects in the cache memory and disk.

Parameters:

localOnly - if true only objects in the local cache are invalidated

Throws:

CacheException - if any cache error occurs

Since:

9.0.4

getVersion

public static java.lang.String getVersion()

GetVersion returns the current version of the cache.

Returns:

the cache version number

Since:

2.0.0

dump

public static void dump()

dumps all the objects in cache to the log file.

Since:

2.0.0

isReady

public static boolean isReady()

returns true if the cache has been initialized, false otherwise.

Returns:

true if the cache has been initialized; false, otherwise.

Since:

2.0.0

isDistributed

public static boolean isDistributed()

returns true if the cache is currently in distributed mode, that it is distributing updates and invalidates within the site, false if all cache actions are local to the process only.

Returns:

true, if cache is distributed; false, otherwise.

Since:

2.0.0

listCacheObjects

public static java.util.Enumeration listCacheObjects()

returns an Enumeration of CacheObjectInfo objects describing the objects in all regions in the cache. CacheObjectInfo will include information such as the object name, the type, what group it is associated with, the reference count, the expiration time if any and the number of accesses.

Returns:

Enumeration of CacheObjectInfo.

Since:

2.0.0

See Also:

CacheObjectInfo

listCacheObjects

public static java.util.Enumeration listCacheObjects(java.lang.String region)

returns an Enumeration of CacheObjectInfo objects describing the objects in specified region in the cache. CacheObjectInfo will include information such as the object name, the type, what group it is associated with, the reference count, the expiration time if any and the number of accesses.

Returns:

Enumeration of CacheObjectInfo.

Since:

2.0.0

See Also:

CacheObjectInfo

setLogSeverity

public static void setLogSeverity(int severity)

sets the log severity of the cache system. This determines which messages the cache formats and logs into the log file.

Since:

2.0.0

See Also:

CacheLogger

getCacheId

public static int getCacheId()

returns the global cache Id in a distributed cache system. The cache Id for different cache process will be unique at any given moment, however, the cache Id can be reused if one cache process exits, and a new cache process joins the system. For example, a distributed cache system may initially has three cache processes, they have cache id 1, 2, 3 respectively. Then, cache process with cache id 2 exit, and a new cache process joins the distributed cache system, this new cache process will get cache id 2.

Returns:

the global unique cache id (>=1) in the distributed cache system or -1 if the cache is local.

Since:

2.0.0

updateStats

public static void updateStats()

aggregate the statics for the cache.

The statistics for the cache are aggregated as a background task at the interval specified by the "cleanInterval" configuration parameter or by directly calling updateStats. If a cache is already in the process of aggregating statistics, updateStats will block until the aggregation is complete.

Since:

9.0.4

See Also:

AggregateStatus

getCacheAddress

public static java.lang.String getCacheAddress()

returns the String representation of the address currently being used by this instance of the cache, or null if the cache is not on the network.

Returns:

the address of the current instance of the cache or null if the cache is local.

Since:

2.0.0

getCacheAddressObject

public static oracle.ias.cache.CacheAddress getCacheAddressObject()
                                                           throws CacheException

returns the Object representation of the address of the current instance of the cache, or null if the cache is not on the network.

Returns:

the address of the current instance of the cache or null if the cache is local.

Throws:

CacheException

Since:

9.0.4

getActiveHostInfo

public static CacheHostInfo[] getActiveHostInfo()
                                         throws CacheException

returns an array of CacheHostInfo objects, one for each active member of the cache system

Returns:

an array of CacheHostInfo objects, one for each active member of the cache system

Throws:

CacheException

Since:

9.0.4

getCacheLogger

public static CacheLogger getCacheLogger()

returns a reference to the CacheLogger currently being used by the cache