org.mmbase.cache
Class QueryResultCache

java.lang.Object
  org.mmbase.cache.Cache
      org.mmbase.cache.QueryResultCache

All Implemented Interfaces:

Map, SizeMeasurable

Direct Known Subclasses:

AggregatedResultCache, MultilevelCache, NodeListCache, RelatedNodesCache

public abstract class QueryResultCache

extends Cache

This cache provides a base implementation to cache the result of SearchQuery's. Such a cache links a SearchQuery object to a list of MMObjectNodes. A cache entry is automaticly invalidated if arbitrary node of one of the types present in the SearchQuery is changed (,created or deleted). This mechanism is not very subtle but it is garanteed to be correct. It means though that your cache can be considerably less effective for queries containing node types from which often node are edited.

Since:

MMBase-1.7

Version:

$Id: QueryResultCache.java,v 1.34 2006/06/27 07:31:46 michiel Exp $

Author:

Daniel Ockeloen, Michiel Meeuwissen, Bunst Eunders

See Also:

SearchQuery

Nested Class Summary

Nested classes inherited from class java.util.Map

Map.Entry

Field Summary

Fields inherited from class org.mmbase.cache.Cache

maxEntrySize

Method Summary

void	addReleaseStrategies(List strategies)
void	addReleaseStrategy(ReleaseStrategy releaseStrategy) This method lets you add a release strategy to the cache.
void	clear()
ChainedReleaseStrategy	getReleaseStrategy()
Iterator	observerIterator()
Object	put(Object key, Object value) Like 'put' of LRUHashtable but considers if the cache is active or not.
Object	put(SearchQuery query, List queryResult) Puts a search result in this cache.
Object	remove(Object key) Removes an object from the cache.
String	toString()

Methods inherited from class org.mmbase.cache.Cache

checkCachePolicy, contains, containsKey, containsValue, entrySet, equals, get, getByteSize, getByteSize, getCache, getCaches, getCheapByteSize, getCount, getDefaultMaxEntrySize, getDescription, getHits, getMaxEntrySize, getMisses, getName, getPuts, getRatio, getStats, getTotalByteSize, hashCode, isActive, isEmpty, keySet, main, maxSize, putAll, putCache, putCache, setActive, setMaxSize, size, values

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

addReleaseStrategies

public void addReleaseStrategies(List strategies)

Parameters:

strategies -

addReleaseStrategy

public void addReleaseStrategy(ReleaseStrategy releaseStrategy)

This method lets you add a release strategy to the cache. It will in fact be added to ChainedReleaseStrategy, which is the default base release strategy.

Parameters:

releaseStrategy - A releaseStrategy to add.

getReleaseStrategy

public ChainedReleaseStrategy getReleaseStrategy()

Returns:

Returns the releaseStrategy.

observerIterator

public Iterator observerIterator()

Returns:

an iterator of all observer instances

put

public Object put(Object key,
                  Object value)

Description copied from class: Cache

Like 'put' of LRUHashtable but considers if the cache is active or not.

Specified by:

put in interface Map

Overrides:

put in class Cache

Throws:

ClassCastException - if key not a SearchQuery or value not a List.

put

public Object put(SearchQuery query,
                  List queryResult)

Puts a search result in this cache.

remove

public Object remove(Object key)

Removes an object from the cache. It alsos remove the watch from the observers which are watching this entry.

Specified by:

remove in interface Map

Overrides:

remove in class Cache

Parameters:

key - A SearchQuery object.

See Also:

Map.remove(java.lang.Object)

toString

public String toString()

Overrides:

toString in class Cache

clear

public void clear()

Specified by:

clear in interface Map

Overrides:

clear in class Cache

See Also:

Map.clear()