org.janusgraph.graphdb.transaction.subquerycache

Interface SubqueryCache

All Known Implementing Classes:

EmptySubqueryCache, GuavaSubqueryCache, SubsetSubqueryCache

public interface SubqueryCache

Cache for JointIndexQuery.Subquery results. Cache entries are manually added using get(JointIndexQuery.Subquery, Callable) or put(JointIndexQuery.Subquery, List), and stored in the cache until evicted or invalidated.

Author:

Boxuan Li ([email protected])

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
void	put(JointIndexQuery.Subquery query, List<Object> values) Add given values into cache

Method Detail

getIfPresent

List<Object> getIfPresent(JointIndexQuery.Subquery query)

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

Parameters:

query - a subquery of joint index query

Returns:

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

put

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

Add given values into cache

Parameters:

query - a subquery of joint index query

values - a list of results to be cached

get

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

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

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

void close()

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