Package oracle.stellent.ridc.common.cache

Class ExpiringCache<K,V>

java.lang.Object
oracle.stellent.ridc.common.cache.ExpiringCache<K,V>
@Concealed public class ExpiringCache<K,V> extends Object

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    DEFAULT_BUCKET_COUNT
    Default number of concurrent writes to support : 16 (must be a power of 2)
    static final int
    DEFAULT_BUCKET_INITIAL_SIZE
    Default initial size of a bucket : 8 (must be power of 2)
    static final int
    DEFAULT_BUCKET_READ_COUNT_EXPIRATION_CHECK_INTERVAL
    Default bucket read count interval at which a bucket's entries are additionally checked for expiration (must be a power of 2 minus 1) 31 indicates that expiration check will occur when mReadCount for bucket is at 32,64,96,128,160,192,....
    static final long
    DEFAULT_ENTRY_VALIDITY_MS
    Default validity time/duration of a bucket entry in milliseconds : 10 minutes
    static final int
    UNRESTRICTED_BUCKET_MAX_SIZE
    max size of a bucket : 0 - unlimited
    static final int
    UNRESTRICTED_ENTRY_VALIDITY
    cache entries will never expire due to age : 0 - unlimited Note - cache entries may still be removed in the event a max bucket size is specified

  • Constructor Summary

    Constructors
    Constructor
    Description
    ExpiringCache()
     
    ExpiringCache(int initialCacheSize)
     
    ExpiringCache(int bucketCount, int bucketInitialSize, int bucketMaxSize, long entryValidityMS, int readCountCheckInterval)
     
    ExpiringCache(int initialCacheSize, int maxCacheSize, long entryValidityMS)
     
    ExpiringCache(int initialCacheSize, long entryValidityMS)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Clear all entries from cache.
    V
    get(K key)
    Return value from cache linked to key; otherwise null.
    V
    put(K key, V value)
    Store/replace object in cache, returning existing value if present Supplying a value of null is equivalent to a remove operation
    V
    remove(K key)
    Remove entry from cache linked to key, returning entry value if non-expired; otherwise null.
    long
    removeExpiredEntries()
    Remove expired entries returning an approximation of the number of revised entries now cached
    long
    size()
    Return an approximation of how many entries are cached; Count may include entries potentially expired!

    Methods inherited from class java.lang.Object

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

  • Field Details

    • DEFAULT_BUCKET_COUNT

      public static final int DEFAULT_BUCKET_COUNT
      Default number of concurrent writes to support : 16 (must be a power of 2)
      See Also:

    • DEFAULT_BUCKET_INITIAL_SIZE

      public static final int DEFAULT_BUCKET_INITIAL_SIZE
      Default initial size of a bucket : 8 (must be power of 2)
      See Also:

    • DEFAULT_ENTRY_VALIDITY_MS

      public static final long DEFAULT_ENTRY_VALIDITY_MS
      Default validity time/duration of a bucket entry in milliseconds : 10 minutes
      See Also:

    • DEFAULT_BUCKET_READ_COUNT_EXPIRATION_CHECK_INTERVAL

      public static final int DEFAULT_BUCKET_READ_COUNT_EXPIRATION_CHECK_INTERVAL
      Default bucket read count interval at which a bucket's entries are additionally checked for expiration (must be a power of 2 minus 1) 31 indicates that expiration check will occur when mReadCount for bucket is at 32,64,96,128,160,192,....
      See Also:

    • UNRESTRICTED_BUCKET_MAX_SIZE

      public static final int UNRESTRICTED_BUCKET_MAX_SIZE
      max size of a bucket : 0 - unlimited
      See Also:

    • UNRESTRICTED_ENTRY_VALIDITY

      public static final int UNRESTRICTED_ENTRY_VALIDITY
      cache entries will never expire due to age : 0 - unlimited Note - cache entries may still be removed in the event a max bucket size is specified
      See Also:

  • Constructor Details

    • ExpiringCache

      public ExpiringCache()

    • ExpiringCache

      public ExpiringCache(int initialCacheSize)

    • ExpiringCache

      public ExpiringCache(int initialCacheSize, long entryValidityMS)

    • ExpiringCache

      public ExpiringCache(int initialCacheSize, int maxCacheSize, long entryValidityMS)

    • ExpiringCache

      public ExpiringCache(int bucketCount, int bucketInitialSize, int bucketMaxSize, long entryValidityMS, int readCountCheckInterval)

  • Method Details

    • clear

      public void clear()
      Clear all entries from cache.

    • get

      public V get(K key)
      Return value from cache linked to key; otherwise null.

    • put

      public V put(K key, V value)
      Store/replace object in cache, returning existing value if present Supplying a value of null is equivalent to a remove operation

    • remove

      public V remove(K key)
      Remove entry from cache linked to key, returning entry value if non-expired; otherwise null.

    • removeExpiredEntries

      public long removeExpiredEntries()
      Remove expired entries returning an approximation of the number of revised entries now cached

    • size

      public long size()
      Return an approximation of how many entries are cached; Count may include entries potentially expired!