org.janusgraph.graphdb.query

Interface QueryExecutor<Q extends ElementQuery,R extends JanusGraphElement,B extends BackendQuery>

All Known Implementing Classes:

MetricsQueryExecutor

public interface QueryExecutor<Q extends ElementQuery,R extends JanusGraphElement,B extends BackendQuery>

Executes a given query and its subqueries against an underlying data store and transaction.

Author:

Matthias Broecheler ([email protected])

Method Summary

Modifier and Type	Method and Description
Iterator<R>	execute(Q query, B subquery, Object executionInfo, QueryProfiler profiler) Executes the given sub-query against a data store and returns an iterator over the results.
Iterator<R>	getNew(Q query) Returns all newly created elements in a transactional context that match the given query.
boolean	hasDeletions(Q query) Whether the transactional context contains any deletions that could potentially affect the result set of the given query.
boolean	isDeleted(Q query, R result) Whether the given result entry has been deleted in the transactional context and should hence be removed from the result set.

Method Detail

getNew

Iterator<R> getNew(Q query)

Returns all newly created elements in a transactional context that match the given query.

Parameters:

query -

Returns:

hasDeletions

boolean hasDeletions(Q query)

Whether the transactional context contains any deletions that could potentially affect the result set of the given query. This is used to determine whether results need to be checked for deletion with isDeleted(ElementQuery, org.janusgraph.core.JanusGraphElement).

Parameters:

query -

Returns:

isDeleted

boolean isDeleted(Q query,
                  R result)

Whether the given result entry has been deleted in the transactional context and should hence be removed from the result set.

Parameters:

query -

result -

Returns:

execute

Iterator<R> execute(Q query,
                    B subquery,
                    Object executionInfo,
                    QueryProfiler profiler)

Executes the given sub-query against a data store and returns an iterator over the results. These results are not yet adjusted to any modification made in the transactional context which are done by the QueryProcessor using the other methods of this interface.

Parameters:

query -

subquery -

executionInfo -

profiler -

Returns: