org.janusgraph.graphdb.transaction.subquerycache

Class EmptySubqueryCache

java.lang.Object

org.janusgraph.graphdb.transaction.subquerycache.EmptySubqueryCache

All Implemented Interfaces:

SubqueryCache

public class EmptySubqueryCache
extends Object
implements SubqueryCache

Method Summary

Modifier and Type	Method and Description
void	close() Closes the cache which allows the cache to release allocated memory.
List<Object>	get(JointIndexQuery.Subquery query, Callable<? extends List<Object>> valueLoader) Returns a list of results.
List<Object>	getIfPresent(JointIndexQuery.Subquery query) Return a list of results if given query exists in cache, otherwise return null
static EmptySubqueryCache	getInstance()
void	put(JointIndexQuery.Subquery query, List<Object> values) Add given values into cache

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static EmptySubqueryCache getInstance()

getIfPresent

public List<Object> getIfPresent(JointIndexQuery.Subquery query)

Description copied from interface: SubqueryCache

Return a list of results if given query exists in cache, otherwise return null

Specified by:

getIfPresent in interface SubqueryCache

Parameters:

query - a subquery of joint index query

Returns:

a list of matching results or null if is not in the cache

put

public void put(JointIndexQuery.Subquery query,
                List<Object> values)

Description copied from interface: SubqueryCache

Add given values into cache

Specified by:

put in interface SubqueryCache

Parameters:

query - a subquery of joint index query

values - a list of results to be cached

get

public List<Object> get(JointIndexQuery.Subquery query,
                        Callable<? extends List<Object>> valueLoader)
                 throws Exception

Description copied from interface: SubqueryCache

Returns a list of results. If given query not in cache, call the value loader to retrieve results and put into the cache

Specified by:

get in interface SubqueryCache

Parameters:

query - a subquery of joint index query

valueLoader - a callable that returns a list of results

Returns:

a list of results

Throws:

Exception - if exception thrown when calling the value loader

close

public void close()

Description copied from interface: SubqueryCache

Closes the cache which allows the cache to release allocated memory. Calling any of the other methods after closing a cache has undetermined behavior.

Specified by:

close in interface SubqueryCache