org.datanucleus.store.query.cache

Class AbstractQueryResultsCache

java.lang.Object

org.datanucleus.store.query.cache.AbstractQueryResultsCache

All Implemented Interfaces:

Serializable, QueryResultsCache

Direct Known Subclasses:

SoftQueryResultsCache, StrongQueryResultsCache, WeakQueryResultsCache

public class AbstractQueryResultsCache
extends Object
implements QueryResultsCache

Abstract representation of a query results cache for the query.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractQueryResultsCache(NucleusContext nucleusCtx)

Method Summary

Modifier and Type	Method and Description
void	close() Method to close the cache when no longer needed.
boolean	contains(String queryKey) Accessor for whether the specified query is in the cache
void	evict(Class candidate) Method to evict all queries that use the provided class as candidate.
void	evict(Query query) Evict the query from the results cache.
void	evict(Query query, Map params) Evict the query with the specified params from the results cache.
void	evictAll() Method to clear the cache.
List<Object>	get(String queryKey) Accessor for the results from the cache.
boolean	isEmpty() Accessor for whether the cache is empty.
void	pin(Query query) Method to pin the specified query in the cache, preventing garbage collection.
void	pin(Query query, Map params) Method to pin the specified query in the cache, preventing garbage collection.
List<Object>	put(String queryKey, List<Object> results) Method to put an object in the cache.
int	size() Accessor for the total number of results in the query cache.
void	unpin(Query query) Method to unpin the specified query from the cache, allowing garbage collection.
void	unpin(Query query, Map params) Method to unpin the specified query from the cache, allowing garbage collection.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractQueryResultsCache

public AbstractQueryResultsCache(NucleusContext nucleusCtx)

Method Detail

close

public void close()

Description copied from interface: QueryResultsCache

Method to close the cache when no longer needed. Provides a hook to release resources etc.

Specified by:

close in interface QueryResultsCache

contains

public boolean contains(String queryKey)

Description copied from interface: QueryResultsCache

Accessor for whether the specified query is in the cache

Specified by:

contains in interface QueryResultsCache

Parameters:

queryKey - The query key

Returns:

Whether it is in the cache

evict

public void evict(Class candidate)

Description copied from interface: QueryResultsCache

Method to evict all queries that use the provided class as candidate. This is usually called when an instance of the candidate has been changed in the datastore.

Specified by:

evict in interface QueryResultsCache

Parameters:

candidate - The candidate

evictAll

public void evictAll()

Description copied from interface: QueryResultsCache

Method to clear the cache.

Specified by:

evictAll in interface QueryResultsCache

evict

public void evict(Query query)

Description copied from interface: QueryResultsCache

Evict the query from the results cache.

Specified by:

evict in interface QueryResultsCache

Parameters:

query - The query to evict (evicts all use of this query, with any params)

evict

public void evict(Query query,
                  Map params)

Description copied from interface: QueryResultsCache

Evict the query with the specified params from the results cache.

Specified by:

evict in interface QueryResultsCache

Parameters:

query - The query to evict

params - The parameters

pin

public void pin(Query query,
                Map params)

Description copied from interface: QueryResultsCache

Method to pin the specified query in the cache, preventing garbage collection.

Specified by:

pin in interface QueryResultsCache

Parameters:

query - The query

params - Its params

pin

public void pin(Query query)

Description copied from interface: QueryResultsCache

Method to pin the specified query in the cache, preventing garbage collection.

Specified by:

pin in interface QueryResultsCache

Parameters:

query - The query

unpin

public void unpin(Query query,
                  Map params)

Description copied from interface: QueryResultsCache

Method to unpin the specified query from the cache, allowing garbage collection.

Specified by:

unpin in interface QueryResultsCache

Parameters:

query - The query

params - Its params

unpin

public void unpin(Query query)

Description copied from interface: QueryResultsCache

Method to unpin the specified query from the cache, allowing garbage collection.

Specified by:

unpin in interface QueryResultsCache

Parameters:

query - The query

get

public List<Object> get(String queryKey)

Description copied from interface: QueryResultsCache

Accessor for the results from the cache.

Specified by:

get in interface QueryResultsCache

Parameters:

queryKey - The query key

Returns:

The cached query result ids

isEmpty

public boolean isEmpty()

Description copied from interface: QueryResultsCache

Accessor for whether the cache is empty.

Specified by:

isEmpty in interface QueryResultsCache

Returns:

Whether it is empty.

put

public List<Object> put(String queryKey,
                        List<Object> results)

Description copied from interface: QueryResultsCache

Method to put an object in the cache.

Specified by:

put in interface QueryResultsCache

Parameters:

queryKey - The query key

results - The results for this query

Returns:

The result ids previously associated with this query (if any)

size

public int size()

Description copied from interface: QueryResultsCache

Accessor for the total number of results in the query cache.

Specified by:

size in interface QueryResultsCache

Returns:

Number of queries