Class FedXConnection

java.lang.Object

org.eclipse.rdf4j.sail.helpers.AbstractSailConnection

org.eclipse.rdf4j.federated.FedXConnection

All Implemented Interfaces:

AutoCloseable, SailConnection

public class FedXConnection
extends AbstractSailConnection

An implementation of RepositoryConnection that uses FederationEvalStrategy to evaluate provided queries. Prior to evaluation various optimizations are performed, see FedXOptimizer for further details.

Since 4.0 FedX supports write operations using the supplied WriteStrategy, e.g. by writing to a designated federation member. Note: the WriteStrategy is initialized lazily upon first access to a write operation, see getWriteStrategyInternal().

Implementation notes: - not all methods are implemented as of now

Author:

Andreas Schwarte

See Also:

• FederationEvalStrategy
• WriteStrategy

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	FedXConnection.SailBaseDefaultImpl	A default implementation for AbstractSail.

Field Summary

Fields

Modifier and Type	Field	Description
protected final FedX	federation
protected final FederationContext	federationContext

Constructor Summary

Constructors

Constructor	Description
FedXConnection(FedX federation, FederationContext federationContext)

Method Summary

Modifier and Type	Method	Description
protected void	addStatementInternal(Resource subj, IRI pred, Value obj, Resource... contexts)
protected void	clearInternal(Resource... contexts)
protected void	clearNamespacesInternal()
protected void	closeInternal()
protected void	commitInternal()
protected CloseableIteration<? extends BindingSet>	evaluateInternal(TupleExpr query, Dataset dataset, BindingSet bindings, boolean includeInferred)
Explanation	explain(Explanation.Level level, TupleExpr tupleExpr, Dataset dataset, BindingSet bindings, boolean includeInferred, int timeoutSeconds)	Explain how the TupleExpr will be (or has been) executed/evaluated by returning a TupleExpr (which may or may not be the provided TupleExpr) that has gone through zero or more of the stages prior to and also including execution as specified by the provided level.
protected CloseableIteration<? extends Resource>	getContextIDsInternal()
protected String	getNamespaceInternal(String prefix)
protected CloseableIteration<? extends Namespace>	getNamespacesInternal()
protected CloseableIteration<? extends Statement>	getStatementsInternal(Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts)
protected WriteStrategy	getWriteStrategyInternal()	Return the initialized writeStrategy.
protected boolean	hasStatementInternal(Resource subj, IRI pred, Value obj, boolean includeInferred, Resource[] contexts)
protected void	removeNamespaceInternal(String prefix)
protected void	removeStatementsInternal(Resource subj, IRI pred, Value obj, Resource... contexts)
protected void	rollbackInternal()
protected void	setNamespaceInternal(String prefix, String name)
void	setTransactionSettings(TransactionSetting... settings)	Pass any transaction-specific settings to the SailConnection.
protected long	sizeInternal(Resource... contexts)
protected void	startTransactionInternal()

Methods inherited from class AbstractSailConnection

addStatement, addStatement, autoStartTransaction, begin, begin, bulkAddStatementsInternal, clear, clearNamespaces, close, commit, endUpdate, endUpdateInternal, evaluate, flush, getContextIDs, getNamespace, getNamespaces, getOwner, getSailBase, getStatements, getStatements, getStatementsInternal, getTransactionIsolation, hasActiveIterations, hasStatement, isActive, isActiveOperation, isOpen, iterationClosed, pendingAdds, prepare, prepareInternal, recordDataImportMetricsStatementsAdded, registerIteration, removeNamespace, removeStatement, removeStatements, rollback, setNamespace, setStatementsAdded, setStatementsRemoved, size, startUpdate, transactionActive, verifyIsActive, verifyIsOpen, waitForOtherOperations

Modifier and Type	Method	Description
final void	addStatement(Resource subj, IRI pred, Value obj, Resource... contexts)	Adds a statement to the store.
void	addStatement(UpdateContext op, Resource subj, IRI pred, Value obj, Resource... contexts)	The default implementation buffers added statements until the update operation is complete.
protected void	autoStartTransaction()	Deprecated. Use AbstractSailConnection.verifyIsActive() instead.
void	begin()	Begins a transaction requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction.
void	begin(IsolationLevel isolationLevel)	Begins a transaction with the specified IsolationLevel level, requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction.
protected void	bulkAddStatementsInternal(Collection<? extends Statement> statements)
final void	clear(Resource... contexts)	Removes all statements from the specified/all contexts.
final void	clearNamespaces()	Removes all namespace declarations from the repository.
final void	close()	Closes the connection.
final void	commit()	Commits any updates that have been performed since the last time SailConnection.commit() or SailConnection.rollback() was called.
final void	endUpdate(UpdateContext op)	Indicates that the given op will not be used in any call again.
protected void	endUpdateInternal(UpdateContext op)
final CloseableIteration<? extends BindingSet>	evaluate(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings, boolean includeInferred)	Evaluates the supplied TupleExpr on the data contained in this Sail object, using the (optional) dataset and supplied bindings as input parameters.
void	flush()	Flushes any pending updates and notify changes to listeners as appropriate.
final CloseableIteration<? extends Resource>	getContextIDs()	Returns the set of all unique context identifiers that are used to store statements.
final String	getNamespace(String prefix)	Gets the namespace that is associated with the specified prefix, if any.
final CloseableIteration<? extends Namespace>	getNamespaces()	Gets the namespaces relevant to the data contained in this Sail object.
Thread	getOwner()	This is for internal use only.
protected AbstractSail	getSailBase()
final CloseableIteration<? extends Statement>	getStatements(StatementOrder order, Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts)	Gets all statements from the specified contexts that have a specific subject, predicate and/or object.
final CloseableIteration<? extends Statement>	getStatements(Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts)	Gets all statements from the specified contexts that have a specific subject, predicate and/or object.
protected CloseableIteration<? extends Statement>	getStatementsInternal(StatementOrder order, Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts)
protected IsolationLevel	getTransactionIsolation()	Retrieve the currently set IsolationLevel.
boolean	hasActiveIterations()
final boolean	hasStatement(Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts)	Determines if the store contains any statements from the specified contexts that have a specific subject, predicate and/or object.
boolean	isActive()	Indicates if a transaction is currently active on the connection.
protected boolean	isActiveOperation()
final boolean	isOpen()	Checks whether this SailConnection is open.
protected void	iterationClosed(org.eclipse.rdf4j.sail.helpers.SailBaseIteration<?,?> iter)	Called by SailBaseIteration to indicate that it has been closed.
protected boolean	pendingAdds()
final void	prepare()	Checks for an error state in the active transaction that would force the transaction to be rolled back.
protected void	prepareInternal()
protected final void	recordDataImportMetricsStatementsAdded(Resource... contexts)
protected <T, E extends Exception> CloseableIteration<T>	registerIteration(CloseableIteration<T> iter)	Registers an iteration as active by wrapping it in a SailBaseIteration object and adding it to the list of active iterations.
final void	removeNamespace(String prefix)	Removes a namespace declaration by removing the association between a prefix and a namespace name.
void	removeStatement(UpdateContext op, Resource subj, IRI pred, Value obj, Resource... contexts)	The default implementation buffers removed statements until the update operation is complete.
final void	removeStatements(Resource subj, IRI pred, Value obj, Resource... contexts)	Removes all statements matching the specified subject, predicate and object from the repository.
final void	rollback()	Rolls back the transaction, discarding any uncommitted changes that have been made in this SailConnection.
final void	setNamespace(String prefix, String name)	Sets the prefix for a namespace.
protected void	setStatementsAdded()
protected void	setStatementsRemoved()
final long	size(Resource... contexts)	Returns the number of (explicit) statements in the store, or in specific contexts.
void	startUpdate(UpdateContext op)	Signals the start of an update operation.
protected final boolean	transactionActive()
protected void	verifyIsActive()	Verifies if a transaction is currently active.
protected void	verifyIsOpen()
void	waitForOtherOperations(boolean interrupt)

Methods inherited from class Object

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

Methods inherited from interface SailConnection

getComparator, getSupportedOrders, prepareQuery

Modifier and Type	Method	Description
default Comparator<Value>	getComparator()	Different underlying datastructures may have different ways of ordering statements.
default Set<StatementOrder>	getSupportedOrders(Resource subj, IRI pred, Value obj, Resource... contexts)	The underlying store may support some, but not all, statement orders based on the statement pattern.
default Optional<TupleExpr>	prepareQuery(QueryLanguage ql, Query.QueryType type, String query, String baseURI)	Allows the SailConnection to bypass the standard query parser and provide its own internal TupleExpr implementation.

Field Details

federation

protected final FedX federation

federationContext

protected final FederationContext federationContext

Constructor Details

FedXConnection

public FedXConnection(FedX federation,
 FederationContext federationContext)
               throws SailException

Throws:

SailException

Method Details

setTransactionSettings

public void setTransactionSettings(TransactionSetting... settings)

Description copied from interface: SailConnection

Pass any transaction-specific settings to the SailConnection. This method needs to be called before the transaction is started .

Sail implementations can override this method to receive the transaction settings (to inspect and/or pass them along to any wrapped sail objects). Remember to call super.setTransactionSettings(settings) if you override this method.

Specified by:

setTransactionSettings in interface SailConnection

Overrides:

setTransactionSettings in class AbstractSailConnection

Parameters:

settings - the transaction settings on which the next transaction operates. It may or may not contain the isolation level.

evaluateInternal

protected CloseableIteration<? extends BindingSet> evaluateInternal(TupleExpr query,
 Dataset dataset,
 BindingSet bindings,
 boolean includeInferred)
                                                             throws SailException

Specified by:

evaluateInternal in class AbstractSailConnection

Throws:

SailException

clearInternal

protected void clearInternal(Resource... contexts)
                      throws SailException

Specified by:

clearInternal in class AbstractSailConnection

Throws:

SailException

clearNamespacesInternal

protected void clearNamespacesInternal()
                                throws SailException

Specified by:

clearNamespacesInternal in class AbstractSailConnection

Throws:

SailException

closeInternal

protected void closeInternal()
                      throws SailException

Specified by:

closeInternal in class AbstractSailConnection

Throws:

SailException

commitInternal

protected void commitInternal()
                       throws SailException

Specified by:

commitInternal in class AbstractSailConnection

Throws:

SailException

getContextIDsInternal

protected CloseableIteration<? extends Resource> getContextIDsInternal()
                                                                throws SailException

Specified by:

getContextIDsInternal in class AbstractSailConnection

Throws:

SailException

getNamespaceInternal

protected String getNamespaceInternal(String prefix)
                               throws SailException

Specified by:

getNamespaceInternal in class AbstractSailConnection

Throws:

SailException

getNamespacesInternal

protected CloseableIteration<? extends Namespace> getNamespacesInternal()
                                                                 throws SailException

Specified by:

getNamespacesInternal in class AbstractSailConnection

Throws:

SailException

getStatementsInternal

protected CloseableIteration<? extends Statement> getStatementsInternal(Resource subj,
 IRI pred,
 Value obj,
 boolean includeInferred,
 Resource... contexts)
                                                                 throws SailException

Specified by:

getStatementsInternal in class AbstractSailConnection

Throws:

SailException

hasStatementInternal

protected boolean hasStatementInternal(Resource subj,
 IRI pred,
 Value obj,
 boolean includeInferred,
 Resource[] contexts)

Overrides:

hasStatementInternal in class AbstractSailConnection

addStatementInternal

protected void addStatementInternal(Resource subj,
 IRI pred,
 Value obj,
 Resource... contexts)
                             throws SailException

Specified by:

addStatementInternal in class AbstractSailConnection

Throws:

SailException

removeNamespaceInternal

protected void removeNamespaceInternal(String prefix)
                                throws SailException

Specified by:

removeNamespaceInternal in class AbstractSailConnection

Throws:

SailException

removeStatementsInternal

protected void removeStatementsInternal(Resource subj,
 IRI pred,
 Value obj,
 Resource... contexts)
                                 throws SailException

Specified by:

removeStatementsInternal in class AbstractSailConnection

Throws:

SailException

rollbackInternal

protected void rollbackInternal()
                         throws SailException

Specified by:

rollbackInternal in class AbstractSailConnection

Throws:

SailException

setNamespaceInternal

protected void setNamespaceInternal(String prefix,
 String name)
                             throws SailException

Specified by:

setNamespaceInternal in class AbstractSailConnection

Throws:

SailException

sizeInternal

protected long sizeInternal(Resource... contexts)
                     throws SailException

Specified by:

sizeInternal in class AbstractSailConnection

Throws:

SailException

startTransactionInternal

protected void startTransactionInternal()
                                 throws SailException

Specified by:

startTransactionInternal in class AbstractSailConnection

Throws:

SailException

getWriteStrategyInternal

protected WriteStrategy getWriteStrategyInternal()
                                          throws SailException

Return the initialized writeStrategy. If this has not been done yet,

invalid reference

WriteStrategy#initialize()

is returned. This method guarantees lazy initialization upon the first write operation on this FedXConnection instance.

Returns:

the WriteStrategy

Throws:

SailException

explain

public Explanation explain(Explanation.Level level,
 TupleExpr tupleExpr,
 Dataset dataset,
 BindingSet bindings,
 boolean includeInferred,
 int timeoutSeconds)

Description copied from interface: SailConnection

Explain how the TupleExpr will be (or has been) executed/evaluated by returning a TupleExpr (which may or may not be the provided TupleExpr) that has gone through zero or more of the stages prior to and also including execution as specified by the provided level.

This method is used by the Query interface.

WARNING: This method is experimental and is subject to change or removal without warning. There is currently only partial support for this method in RDF4J and and UnsupportedOperationException where support is lacking.

Parameters:

level - the explanation level, eg. OPTIMIZED

tupleExpr - The tuple expression to evaluate. Mutable.

dataset - The dataset to use for evaluating the query, null to use the Sail's default dataset.

bindings - A set of input parameters for the query evaluation. The keys reference variable names that should be bound to the value they map to.

includeInferred - Indicates whether inferred triples are to be considered in the query result. If false, no inferred statements are returned; if true, inferred statements are returned if available

timeoutSeconds - for explanations that require execution a timeout can be provided in seconds

Returns:

The resulting tuple expression after being run through the specified level