Class SourceSelection

java.lang.Object

org.eclipse.rdf4j.federated.optimizer.SourceSelection

public class SourceSelection
extends Object

Perform source selection during optimization

Author:

Andreas Schwarte

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	SourceSelection.CheckTaskPair
protected static class	SourceSelection.ParallelCheckTask	Task for sending an ASK request to the endpoints (for source selection)
protected static class	SourceSelection.SourceSelectionExecutorWithLatch

Field Summary

Fields

Modifier and Type	Field	Description
protected final SourceSelectionCache	cache
protected final List<Endpoint>	endpoints
protected final QueryInfo	queryInfo
protected Map<StatementPattern, List<StatementSource>>	stmtToSources	Map statements to their sources.

Constructor Summary

Constructors

Constructor	Description
SourceSelection(List<Endpoint> endpoints, SourceSelectionCache cache, QueryInfo queryInfo)

Method Summary

Modifier and Type	Method	Description
protected void	addSource(StatementPattern stmt, StatementSource source)	Add a source to the given statement in the map (synchronized through map)
void	doSourceSelection(List<StatementPattern> stmts)	Perform source selection for the provided statements using cache or remote ASK queries.
Set<Endpoint>	getRelevantSources()	Retrieve a set of relevant sources for this query.

Methods inherited from class java.lang.Object

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

Field Details

endpoints

protected final List<Endpoint> endpoints

cache

protected final SourceSelectionCache cache

queryInfo

protected final QueryInfo queryInfo

stmtToSources

protected Map<StatementPattern, List<StatementSource>> stmtToSources

Map statements to their sources. Use synchronized access!

Constructor Details

SourceSelection

public SourceSelection(List<Endpoint> endpoints,
 SourceSelectionCache cache,
 QueryInfo queryInfo)

Method Details

doSourceSelection

public void doSourceSelection(List<StatementPattern> stmts)

Perform source selection for the provided statements using cache or remote ASK queries. Remote ASK queries are evaluated in parallel using the concurrency infrastructure of FedX. Note, that this method is blocking until every source is resolved. The statement patterns are replaced by appropriate annotations in this optimization.

Parameters:

stmts -

getRelevantSources

public Set<Endpoint> getRelevantSources()

Retrieve a set of relevant sources for this query.

Returns:

the relevant sources

addSource

protected void addSource(StatementPattern stmt,
 StatementSource source)

Add a source to the given statement in the map (synchronized through map)

Parameters:

stmt -

source -