IBM WebSphere Application ServerTM
Release 8

com.ibm.wsspi.cache
Class CacheEntry

java.lang.Object
  extended by com.ibm.wsspi.cache.CacheEntry

public class CacheEntry
extends java.lang.Object

A CacheEntry is a struct object that holds the cache id and value, as well as metadata for caching. The information in these variables is obtained from the EntryInfo object used when the entry was cached.


Field Summary
 CacheEntry cacheEntry
           
 
Constructor Summary
CacheEntry(CacheEntry ce)
          Constructor for wrapping the cache entry which is used by Cache Monitor.
 
Method Summary
 int getCacheType()
          Returns the type of CacheEntry (CACHE_TYPE_DEFAULT or CACHE_TYPE_JAXRPC) ALL implementors of this method other than Dynacache should return CACHE_TYPE_DEFAULT for this method.
 long getCacheValueSize()
          Returns the best-effort size of the cache entry's value.
 java.util.Enumeration getDataIds()
          Returns all IDs (cache IDs and data IDs) that this entry depends on for invalidation.
 byte[] getDisplayValue()
          Returns the entry's value in a displayable format.
 long getExpirationTime()
          Returns the absolute time when the entry should expire.
 java.lang.String getExternalCacheGroupId()
          Returns the name this the cache entry belongs too.
 java.lang.String getId()
          Returns the unique identifier of this cached entry.
 int getPriority()
          Returns the priority of this cache entry, which determines how long the entry will stay in cache when it is not being used.
 int getSharingPolicy()
          Returns the sharing policy of this entry.
 java.util.Enumeration getTemplates()
          Returns all templates that this entry depends on for invalidation.
 int getTimeLimit()
          Returns the maximum interval of time in seconds that the entry is allowed to stay in the cache.
 long getTimeStamp()
          Returns the creation time of this entry.
 boolean isBatchEnabled()
          Deprecated. The updates for Push or Push-Pull sharing policies are always done in an asynchronous batch mode. It always returns true.
 void refreshEntry()
          This mimics a cache Hit, refreshing an entries spot in the replacement algorithm.
 java.lang.String toString()
          Returns the string representation of cache entry.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

cacheEntry

public CacheEntry cacheEntry
Constructor Detail

CacheEntry

public CacheEntry(CacheEntry ce)
Constructor for wrapping the cache entry which is used by Cache Monitor.

Parameters:
ce - Cache entry instance
Method Detail

getCacheType

public int getCacheType()
Returns the type of CacheEntry (CACHE_TYPE_DEFAULT or CACHE_TYPE_JAXRPC) ALL implementors of this method other than Dynacache should return CACHE_TYPE_DEFAULT for this method.

Returns:
cache type

getTemplates

public java.util.Enumeration getTemplates()
Returns all templates that this entry depends on for invalidation. For a JSP/servlet, a template is the URI for this entry.

Returns:
An Enumeration of the templates.

getDataIds

public java.util.Enumeration getDataIds()
Returns all IDs (cache IDs and data IDs) that this entry depends on for invalidation. Its elements are Strings. They are the identifiers used in the invalidateById methods to invalidate all cache entries having a dependency on these IDs. Data IDs must be unique within the same scope as cache IDs.

Returns:
An Enumeration of the IDs.

getTimeLimit

public int getTimeLimit()
Returns the maximum interval of time in seconds that the entry is allowed to stay in the cache. The entry may be discarded via LRU replacement prior to this time. A negative value indicates no time limit.

Returns:
The time limit.

getExpirationTime

public long getExpirationTime()
Returns the absolute time when the entry should expire. The entry may be discarded via LRU replacement prior to this time. A negative value indicates no expiration time.

Returns:
The expiration time.

getTimeStamp

public long getTimeStamp()
Returns the creation time of this entry.

Returns:
The creation timestamp.

getPriority

public int getPriority()
Returns the priority of this cache entry, which determines how long the entry will stay in cache when it is not being used. A larger priority gives an entry a longer time in the cache. The value of priority should be based on the ratio of the cost of computing the entry to the cost of the memory in the cache (the size of the entry). The default is 1.

Returns:
This entry's priority.

getSharingPolicy

public int getSharingPolicy()
Returns the sharing policy of this entry. In a multi-JVM environment, this indicates whether the cache entry should be EntryInfo.NOT_SHARED, EntryInfo.SHARED_PUSH_PULL or EntryInfo.SHARED_PUSH. The default is NOT_SHARED.

Returns:
The sharing policy.

isBatchEnabled

public boolean isBatchEnabled()
Deprecated. The updates for Push or Push-Pull sharing policies are always done in an asynchronous batch mode. It always returns true.

In a multi-JVM environment, this indicates whether updates to the cache entry (when using EntryInfo.SHARED_PUSH) will be written out immediately or in a batched, asynchronous fashion.

Returns:
True if batch is enabled, false otherwise.

getId

public java.lang.String getId()
Returns the unique identifier of this cached entry. It must be unique within the scope of the group of Cache instances. Having this in the CacheEntry allows an entry obtained via the LRU array to know how to find it in the entryHashtable.

Returns:
The String ID of this CacheEntry.

getDisplayValue

public byte[] getDisplayValue()
Returns the entry's value in a displayable format.

Returns:
The entry's value.

refreshEntry

public void refreshEntry()
This mimics a cache Hit, refreshing an entries spot in the replacement algorithm.


getCacheValueSize

public long getCacheValueSize()
Returns the best-effort size of the cache entry's value.

Returns:
The best-effort determination of the size of the cache entry's value. If the size cannot be determined, the return value is -1;

toString

public java.lang.String toString()
Returns the string representation of cache entry.

Overrides:
toString in class java.lang.Object
Returns:
string representation of cache entry

getExternalCacheGroupId

public java.lang.String getExternalCacheGroupId()
Returns the name this the cache entry belongs too.

Returns:
null of this cache entry is not cached externally

IBM WebSphere Application ServerTM
Release 8