org.apache.lucene.search

Class FilterManager

public class FilterManager extends Object

Filter caching singleton. It can be used by RemoteCachingWrapperFilter or just to save filters locally for reuse. This class makes it possble to cache Filters even when using RMI, as it keeps the cache on the seaercher side of the RMI connection. Also could be used as a persistent storage for any filter as long as the filter provides a proper hashCode(), as that is used as the key in the cache. The cache is periodically cleaned up from a separate thread to ensure the cache doesn't exceed the maximum size.

Author: Matt Ericson

Nested Class Summary
protected class	FilterManager.FilterCleaner Keeps the cache from getting too big.
protected class	FilterManager.FilterItem Holds the filter and the last time the filter was used, to make LRU-based cache cleaning possible.

Field Summary
protected Map	cache The cache itself
protected int	cacheCleanSize Maximum allowed cache size
protected long	cleanSleepTime Cache cleaning frequency
protected static int	DEFAULT_CACHE_CLEAN_SIZE The default maximum number of Filters in the cache
protected static long	DEFAULT_CACHE_SLEEP_TIME The default frequency of cache clenup
protected FilterManager.FilterCleaner	filterCleaner Cache cleaner that runs in a separate thread
protected static FilterManager	manager

Constructor Summary
protected	FilterManager() Sets up the FilterManager singleton.

Method Summary
Filter	getFilter(Filter filter) Returns the cached version of the filter.
static FilterManager	getInstance()
void	setCacheSize(int cacheCleanSize) Sets the max size that cache should reach before it is cleaned up
void	setCleanThreadSleepTime(long cleanSleepTime) Sets the cache cleaning frequency in milliseconds.

Parameters: filter The input filter

Returns: The cached version of the filter

getInstance

public static FilterManager getInstance()

setCacheSize

public void setCacheSize(int cacheCleanSize)

Sets the max size that cache should reach before it is cleaned up

Parameters: cacheCleanSize maximum allowed cache size

setCleanThreadSleepTime

public void setCleanThreadSleepTime(long cleanSleepTime)

Sets the cache cleaning frequency in milliseconds.

Parameters: cleanSleepTime cleaning frequency in millioseconds

Class FilterManager

Field Detail

cache

cacheCleanSize

cleanSleepTime

DEFAULT_CACHE_CLEAN_SIZE

DEFAULT_CACHE_SLEEP_TIME

filterCleaner

manager

Constructor Detail

FilterManager

Method Detail

getFilter

getInstance

setCacheSize

setCleanThreadSleepTime