| org.jivesoftware.util.cache.Cache
| Cache | | public interface Cache extends java.util.Map<K, V>(Code) | | General purpose cache. It stores objects associated with unique keys in
memory for fast access. All keys and values added to the cache must
implement the Serializable interface. Values may implement the Cacheable
interface, which allows the cache to determine object size much more quickly.
These restrictions allow a cache to never grow larger than a specified number
of bytes and to optionally be distributed over a cluster of servers.
If the cache does grow too large, objects will be removed such that those
that are accessed least frequently are removed first. Because expiration
happens automatically, the cache makes no gaurantee as to how long
an object will remain in cache after it is put in.
Optionally, a maximum lifetime for all objects can be specified. In that
case, objects will be deleted from cache after that amount of time, even
if they are frequently accessed. This feature is useful if objects put in
cache represent data that should be periodically refreshed; for example,
information from a database.
All cache operations are thread safe.
See Also: Cacheable |
| Method Summary | |
| long | getCacheHits()
Returns the number of cache hits. | | long | getCacheMisses()
Returns the number of cache misses. | | int | getCacheSize()
Returns the size of the cache contents in bytes. | | long | getMaxCacheSize()
Returns the maximum size of the cache in bytes. | | long | getMaxLifetime()
Returns the maximum number of milliseconds that any object can live
in cache. | | String | getName()
Returns the name of the cache. | | void | setMaxCacheSize(int maxSize)
Sets the maximum size of the cache in bytes. | | void | setMaxLifetime(long maxLifetime)
Sets the maximum number of milliseconds that any object can live
in cache. | | void | setName(String name)
|
| getCacheHits | | long getCacheHits()(Code) | | Returns the number of cache hits. A cache hit occurs every
time the get method is called and the cache contains the requested
object.
Keeping track of cache hits and misses lets one measure how efficient
the cache is; the higher the percentage of hits, the more efficient.
the number of cache hits. |
| getCacheMisses | | long getCacheMisses()(Code) | | Returns the number of cache misses. A cache miss occurs every
time the get method is called and the cache does not contain the
requested object.
Keeping track of cache hits and misses lets one measure how efficient
the cache is; the higher the percentage of hits, the more efficient.
the number of cache hits. |
| getCacheSize | | int getCacheSize()(Code) | | Returns the size of the cache contents in bytes. This value is only a
rough approximation, so cache users should expect that actual VM
memory used by the cache could be significantly higher than the value
reported by this method.
the size of the cache contents in bytes. |
| getMaxCacheSize | | long getMaxCacheSize()(Code) | | Returns the maximum size of the cache in bytes. If the cache grows larger
than the max size, the least frequently used items will be removed. If
the max cache size is set to -1, there is no size limit.
the maximum size of the cache in bytes. |
| getMaxLifetime | | long getMaxLifetime()(Code) | | Returns the maximum number of milliseconds that any object can live
in cache. Once the specified number of milliseconds passes, the object
will be automatically expried from cache. If the max lifetime is set
to -1, then objects never expire.
the maximum number of milliseconds before objects are expired. |
| getName | | String getName()(Code) | | Returns the name of the cache.
the name of the cache. |
| setMaxCacheSize | | void setMaxCacheSize(int maxSize)(Code) | | Sets the maximum size of the cache in bytes. If the cache grows larger
than the max size, the least frequently used items will be removed. If
the max cache size is set to -1, there is no size limit.
Parameters:
maxSize - the maximum size of the cache in bytes. |
| setMaxLifetime | | void setMaxLifetime(long maxLifetime)(Code) | | Sets the maximum number of milliseconds that any object can live
in cache. Once the specified number of milliseconds passes, the object
will be automatically expried from cache. If the max lifetime is set
to -1, then objects never expire.
Parameters:
maxLifetime - the maximum number of milliseconds before objects are expired. |
| setName | | void setName(String name)(Code) | | Sets the name of the cache
Parameters:
name - the name of the cache |
|
|