org.datanucleus.store.query.cache

Interface QueryResultsCache

All Superinterfaces:

Serializable

All Known Implementing Classes:

AbstractQueryResultsCache, JavaxCacheQueryResultCache, SoftQueryResultsCache, StrongQueryResultsCache, WeakQueryResultsCache

public interface QueryResultsCache
extends Serializable

Cache for query results.

Method Summary

Methods

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.

Method Detail

close

void close()

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

evict

void evict(Class candidate)

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.

Parameters:

candidate - The candidate

evict

void evict(Query query)

Evict the query from the results cache.

Parameters:

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

evict

void evict(Query query,
         Map params)

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

Parameters:

query - The query to evict

params - The parameters

evictAll

void evictAll()

Method to clear the cache.

pin

void pin(Query query)

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

Parameters:

query - The query

pin

void pin(Query query,
       Map params)

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

Parameters:

query - The query

params - Its params

unpin

void unpin(Query query)

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

Parameters:

query - The query

unpin

void unpin(Query query,
         Map params)

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

Parameters:

query - The query

params - Its params

isEmpty

boolean isEmpty()

Accessor for whether the cache is empty.

Returns:

Whether it is empty.

size

int size()

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

Returns:

Number of queries

get

List<Object> get(String queryKey)

Accessor for the results from the cache.

Parameters:

queryKey - The query key

Returns:

The cached query result ids

put

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

Method to put an object in the cache.

Parameters:

queryKey - The query key

results - The results for this query

Returns:

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

contains

boolean contains(String queryKey)

Accessor for whether the specified query is in the cache

Parameters:

queryKey - The query key

Returns:

Whether it is in the cache