org.apache.cayenne.cache
Class MapQueryCache

java.lang.Object
  extended by org.apache.cayenne.cache.MapQueryCache
All Implemented Interfaces:
Serializable, QueryCache

public class MapQueryCache
extends Object
implements QueryCache, Serializable

A default implementation of the QueryCache interface that stores data in a non-expiring LRUMap.

Since:
3.0
See Also:
Serialized Form

Field Summary
static int DEFAULT_CACHE_SIZE
           
protected  Map<String,org.apache.cayenne.cache.MapQueryCache.CacheEntry> map
           
 
Constructor Summary
MapQueryCache()
           
MapQueryCache(int maxSize)
           
 
Method Summary
 void clear()
          Clears all cache entries.
 List get(QueryMetadata metadata)
          Returns a cached query result for the given QueryMetadata or null if the result is not cached or is expired.
 List get(QueryMetadata metadata, QueryCacheEntryFactory factory)
          Returns a non-null cached value.
 void put(QueryMetadata metadata, List results)
           
 void remove(String key)
          Removes a single entry from cache.
 void removeGroup(String groupKey)
          Removes a group of entries identified by group key.
 int size()
          Returns the number of entries currently in the cache, including expired but not removed entries.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_CACHE_SIZE

public static final int DEFAULT_CACHE_SIZE
See Also:
Constant Field Values

map

protected Map<String,org.apache.cayenne.cache.MapQueryCache.CacheEntry> map
Constructor Detail

MapQueryCache

public MapQueryCache()

MapQueryCache

public MapQueryCache(int maxSize)
Method Detail

get

public List get(QueryMetadata metadata)
Description copied from interface: QueryCache
Returns a cached query result for the given QueryMetadata or null if the result is not cached or is expired.

Specified by:
get in interface QueryCache

get

public List get(QueryMetadata metadata,
                QueryCacheEntryFactory factory)
Returns a non-null cached value. If it is not present in the cache, it is obtained by calling QueryCacheEntryFactory.createObject() without blocking the cache. As a result there is a potential of multiple threads to be updating cache in parallel - this wouldn't lead to corruption of the cache, but can be suboptimal.

Specified by:
get in interface QueryCache

put

public void put(QueryMetadata metadata,
                List results)
Specified by:
put in interface QueryCache

remove

public void remove(String key)
Description copied from interface: QueryCache
Removes a single entry from cache.

Specified by:
remove in interface QueryCache

removeGroup

public void removeGroup(String groupKey)
Description copied from interface: QueryCache
Removes a group of entries identified by group key. Note that depending on implementation this method may either actively remove the entries belonging to the group or just mark them as expired, so that they are refreshed on the next access. In the former case the cache size would shrink, but in the later the cache size will not change after calling this method.

Specified by:
removeGroup in interface QueryCache

clear

public void clear()
Description copied from interface: QueryCache
Clears all cache entries.

Specified by:
clear in interface QueryCache

size

public int size()
Description copied from interface: QueryCache
Returns the number of entries currently in the cache, including expired but not removed entries.

Specified by:
size in interface QueryCache


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