Package com.ibm.wsspi.cache

Class CacheEntry

java.lang.Object
com.ibm.wsspi.cache.CacheEntry
public class CacheEntry extends 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

    Fields
    Modifier and Type
    Field
    Description
    CacheEntry
    cacheEntry
     

  • Constructor Summary

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

  • Method Summary

    Modifier and Type
    Method
    Description
    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.
    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.
    String
    getExternalCacheGroupId()
    Returns the name this the cache entry belongs too.
    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.
    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.
    void
    refreshEntry()
    This mimics a cache Hit, refreshing an entries spot in the replacement algorithm.
    String
    toString()
    Returns the string representation of cache entry.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

  • Constructor Details

    • CacheEntry

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

  • Method Details

    • 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 Enumeration getTemplates()
      Returns all templates that this entry depends on for invalidation. For a JSP/servlet, a template is the URI for this entry.
      • For a top-level entry (eg, a JSP/Servlet that is externally requested), this is obtained from the HTTP request object's URL. It can be set either by the server or by the top-level JSP/Servlet.
      • For a contained entry, this is the JSP/Servlet file name URL (the parameter that would be used in the callPage method). It can be set either by the JSP/Servlet it names or its containing JSP/Servlet, plus other information from the request object.
      Returns:
      An Enumeration of the templates.

    • getDataIds

      public 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 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 String toString()
      Returns the string representation of cache entry.
      Overrides:
      toString in class Object
      Returns:
      string representation of cache entry

    • getExternalCacheGroupId

      public String getExternalCacheGroupId()
      Returns the name this the cache entry belongs too.
      Returns:
      null of this cache entry is not cached externally