Class SparqlEvaluationContext

Stores information about the Evaluation of a Query during its evaluation.

Inheritance

object

SparqlEvaluationContext

Implements

IPatternEvaluationContext

ISparqlDescribeContext

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: VDS.RDF.Query

Assembly: dotNetRdf.dll

Syntax

public class SparqlEvaluationContext : IPatternEvaluationContext, ISparqlDescribeContext

Constructors

SparqlEvaluationContext(SparqlQuery, ISparqlDataset, ISparqlQueryAlgebraProcessor<BaseMultiset, SparqlEvaluationContext>, LeviathanQueryOptions)

Creates a new Evaluation Context for the given Query over the given Dataset using a specific processor.

Declaration

public SparqlEvaluationContext(SparqlQuery q, ISparqlDataset data, ISparqlQueryAlgebraProcessor<BaseMultiset, SparqlEvaluationContext> processor, LeviathanQueryOptions options)

Parameters

Type	Name	Description
SparqlQuery	q	Query.
ISparqlDataset	data	Dataset.
ISparqlQueryAlgebraProcessor<BaseMultiset, SparqlEvaluationContext>	processor	Query Processor.
LeviathanQueryOptions	options	The query processor options to use.

SparqlEvaluationContext(SparqlQuery, ISparqlDataset, LeviathanQueryOptions)

Creates a new Evaluation Context for the given Query over the given Dataset.

Declaration

public SparqlEvaluationContext(SparqlQuery q, ISparqlDataset data, LeviathanQueryOptions options)

Parameters

Type	Name	Description
SparqlQuery	q	Query.
ISparqlDataset	data	Dataset.
LeviathanQueryOptions	options	The query processor options to use.

SparqlEvaluationContext(SparqlResultBinder, LeviathanQueryOptions)

Creates a new Evaluation Context which is a Container for the given Result Binder.

Declaration

public SparqlEvaluationContext(SparqlResultBinder binder, LeviathanQueryOptions options)

Parameters

Type	Name	Description
SparqlResultBinder	binder
LeviathanQueryOptions	options	The query processor options to use.

Properties

Binder

Gets/Sets the Results Binder.

Declaration

public SparqlResultBinder Binder { get; set; }

Property Value

Type	Description
SparqlResultBinder

Data

Gets the Dataset the query is over.

Declaration

public ISparqlDataset Data { get; }

Property Value

Type	Description
ISparqlDataset

InputMultiset

Gets/Sets the Input Multiset.

Declaration

public BaseMultiset InputMultiset { get; set; }

Property Value

Type	Description
BaseMultiset

this[string]

Gets/Sets a Object that should be persisted over the entire Evaluation Context.

Declaration

public object this[string key] { get; set; }

Parameters

Type	Name	Description
string	key	Key.

Property Value

Type	Description
object

Remarks

May be used by parts of the Evaluation Process that need to ensure a persistent state across the entire Evaluation Query (e.g. the implementation of the BNODE() function).

NodeComparer

Get the comparer to use when ordering nodes during query processing.

Declaration

public ISparqlNodeComparer NodeComparer { get; }

Property Value

Type	Description
ISparqlNodeComparer

Options

Get the configured query options for this evaluation context.

Declaration

public LeviathanQueryOptions Options { get; }

Property Value

Type	Description
LeviathanQueryOptions

OrderingComparer

Get the comparer to use when sorting query results.

Declaration

public SparqlOrderingComparer OrderingComparer { get; }

Property Value

Type	Description
SparqlOrderingComparer

OutputMultiset

Gets/Sets the Output Multiset.

Declaration

public BaseMultiset OutputMultiset { get; set; }

Property Value

Type	Description
BaseMultiset

Processor

Gets the custom query processor that is in use (if any).

Declaration

public ISparqlQueryAlgebraProcessor<BaseMultiset, SparqlEvaluationContext> Processor { get; }

Property Value

Type	Description
ISparqlQueryAlgebraProcessor<BaseMultiset, SparqlEvaluationContext>

Query

Gets the Query that is being evaluated.

Declaration

public SparqlQuery Query { get; }

Property Value

Type	Description
SparqlQuery

QueryTime

Retrieves the Time in milliseconds the query took to evaluate.

Declaration

public long QueryTime { get; }

Property Value

Type	Description
long

QueryTimeTicks

Retrieves the Time in ticks the query took to evaluate.

Declaration

public long QueryTimeTicks { get; }

Property Value

Type	Description
long

QueryTimeout

Gets the Query Timeout used for the Query.

Declaration

public long QueryTimeout { get; }

Property Value

Type	Description
long

Remarks

This is taken either from the Timeout property of the SparqlQuery to which this evaluation context pertains (if any) or from the the processor-defined timeout value passed as a parameter to StartExecution(long) method. You cannot set the Query Timeout to be higher than the processor-defined timeout unless the processor-defined timeout is set to zero (i.e. no processor-defined timeout).

RemainingTimeout

Gets the Remaining Timeout i.e. the Timeout taking into account time already elapsed.

Declaration

public long RemainingTimeout { get; }

Property Value

Type	Description
long

Remarks

If there is no timeout then this is always zero, if there is a timeout this is always >= 1 since any operation that wants to respect the timeout must have a non-zero timeout to actually timeout properly.

RigorousEvaluation

Gets whether pattern evaluation should use rigorous evaluation mode.

Declaration

public bool RigorousEvaluation { get; }

Property Value

Type	Description
bool

TrimTemporaryVariables

Gets/Sets whether BGPs should trim temporary variables.

Declaration

public bool TrimTemporaryVariables { get; set; }

Property Value

Type	Description
bool

TripleIndex

Get the index that provides access to the underlying data being queried.

Declaration

public ITripleIndex TripleIndex { get; }

Property Value

Type	Description
ITripleIndex

UriFactory

Get the factory to use when creating URI instances.

Declaration

public IUriFactory UriFactory { get; }

Property Value

Type	Description
IUriFactory

Methods

CalculateTimeout(long)

Return the execution timeout to be applied to this evaluation context given the specified processor-defined maximum execution timeout.

Declaration

public long CalculateTimeout(long maxTimeout)

Parameters

Type	Name	Description
long	maxTimeout

Returns

Type	Description
long	The execution timeout for the query in this context (if any).

CheckTimeout()

Checks whether Execution should Time out.

Declaration

public void CheckTimeout()

Exceptions

Type	Condition
RdfQueryTimeoutException	Thrown if the Query has exceeded the Execution Timeout.

ContainsValue(string, INode)

Gets whether the evaluation context contains a binding of the specified value to the specified variable.

Declaration

public bool ContainsValue(string varName, INode value)

Parameters

Type	Name	Description
string	varName	The name of the variable to look for.
INode	value	The expected value.

Returns

Type	Description
bool	True if the evaluation context contains a binding for varName to value, false otherwise.

ContainsVariable(string)

Get whether the specified variable is found in the evaluation context.

Declaration

public bool ContainsVariable(string varName)

Parameters

Type	Name	Description
string	varName	The name of the variable to look for.

Returns

Type	Description
bool	True if the evaluation context contains a whose name matches varName, false otherwise.

EndExecution()

Ends the Execution Timer.

Declaration

public void EndExecution()

Evaluate(ISparqlAlgebra)

Evaluates an Algebra Operator in this Context using the current Query Processor (if any) or the default query processor.

Declaration

public BaseMultiset Evaluate(ISparqlAlgebra algebra)

Parameters

Type	Name	Description
ISparqlAlgebra	algebra	Algebra.

Returns

Type	Description
BaseMultiset

Evaluate(TriplePattern)

Evaluate a triple pattern.

Declaration

public void Evaluate(TriplePattern triplePattern)

Parameters

Type	Name	Description
TriplePattern	triplePattern

GetHttpClient(Uri)

Return an HttpClient instance to use when connecting to a specific URI endpoint.

Declaration

public HttpClient GetHttpClient(Uri endpointUri)

Parameters

Type	Name	Description
Uri	endpointUri	The endpoint to connect to.

Returns

Type	Description
HttpClient	An HttpClient instance to use for connections to the specified endpoint.

GetNodes(INodeFactory)

Get the nodes to be described.

Declaration

public IEnumerable<INode> GetNodes(INodeFactory factory)

Parameters

Type	Name	Description
INodeFactory	factory

Returns

Type	Description
IEnumerable<INode>

GetQuotedTriples(QuotedTriplePattern)

Return all quoted triples in the dataset that match the specified pattern.

Declaration

public IEnumerable<ITripleNode> GetQuotedTriples(QuotedTriplePattern qtp)

Parameters

Type	Name	Description
QuotedTriplePattern	qtp

Returns

Type	Description
IEnumerable<ITripleNode>

GetTriples(IMatchTriplePattern)

Gets the Enumeration of Triples that should be assessed for matching the pattern.

Declaration

public IEnumerable<Triple> GetTriples(IMatchTriplePattern triplePattern)

Parameters

Type	Name	Description
IMatchTriplePattern	triplePattern	The pattern to be matched.

Returns

Type	Description
IEnumerable<Triple>

StartExecution(long)

Starts the Execution Timer.

Declaration

public void StartExecution(long maxTimeout)

Parameters

Type	Name	Description
long	maxTimeout	The maximum time (in milliseconds) to allow the query to run for. This may be overridden by the timeout specified in the query itself.

Remarks

A value of zero or less for maxTimeout indicates no timeout. If a finite timeout is specified both by maxTimeout and in the query, then the shorter of these two timeout values will be used.

Implements

IPatternEvaluationContext

ISparqlDescribeContext

Extension Methods

Extensions.ToSafeString(object)

Extensions.AsEnumerable<T>(T)