private SparqlQuery CreateSparqlQuery(IQuery sparqlQuery, out SparqlQueryVariables variables)
{
SparqlQueryParser parser = new SparqlQueryParser();
bool isQueryOptimized = false;
return(parser.ParseFromString(ParseQuery(sparqlQuery, out variables, ref isQueryOptimized)));
}
private string ParseQuery(IQuery sparqlQuery, out SparqlQueryVariables variables, ref bool isQueryOptimized)
{
var queryVisitor = new SparqlQueryVisitor(isQueryOptimized);
queryVisitor.MetaGraphUri = MetaGraphUri;
queryVisitor.VisitQuery(sparqlQuery);
variables = queryVisitor.Variables;
isQueryOptimized = queryVisitor.IsQueryOptimized;
return(queryVisitor.CommandText);
}
/// <inheritdoc />
public virtual SparqlQuery GetSparqlQuery(IQuery sparqlQuery, out SparqlQueryVariables variables)
{
GenericSparqlQueryVisitor queryVisitor = new GenericSparqlQueryVisitor()
{
MetaGraphUri = MetaGraphUri
};
queryVisitor.VisitQuery(sparqlQuery);
variables = queryVisitor.Variables;
SparqlQueryParser parser = new SparqlQueryParser();
return(parser.ParseFromString(queryVisitor.CommandText));
}
/// <inheritdoc />
public override SparqlResultSet ExecuteSelect(IQuery sparqlQuery, out SparqlQueryVariables variables)
{
bool isQueryOptimized = Math.Pow(Store.Triples.Count(), 2) > QueryOptimizationTriplesCountThreshold;
string commandText = ParseQuery(sparqlQuery, out variables, ref isQueryOptimized);
var parser = new SparqlQueryParser();
if (!isQueryOptimized)
{
return((SparqlResultSet)_processor.ProcessQuery(parser.ParseFromString(commandText)));
}
return(ExecuteOptimizedSelect(commandText, variables, parser));
}
private SparqlResultSet ExecuteOptimizedSelect(string commandText, SparqlQueryVariables variables, SparqlQueryParser parser)
{
var parametrizedCommandText = new SparqlParameterizedString(commandText);
var metaGraphQuery = new SparqlQueryParser().ParseFromString(
String.Format(
"SELECT ?{0} WHERE {{ GRAPH <{2}> {{ ?{0} <http://xmlns.com/foaf/0.1/primaryTopic> ?{1} . }} }}",
variables.MetaGraph,
variables.Entity,
MetaGraphUri));
IEnumerable <SparqlResult> result = new List <SparqlResult>();
SparqlQueryVariables queryVariables = variables;
Parallel.ForEach(
((SparqlResultSet)_processor.ProcessQuery(metaGraphQuery)).Results,
(row, state) => ProcessPartialResult(parametrizedCommandText, queryVariables, parser, (List <SparqlResult>)result, row, state));
return(new SparqlResultSet(result));
}
private void ProcessPartialResult(
SparqlParameterizedString parametrizedCommandText,
SparqlQueryVariables queryVariables,
SparqlQueryParser parser,
List <SparqlResult> result,
SparqlResult row,
ParallelLoopState state)
{
if (state.IsStopped)
{
return;
}
SparqlQuery query;
lock (parametrizedCommandText)
{
parametrizedCommandText.SetUri("graph", ((IUriNode)row[queryVariables.MetaGraph]).Uri);
query = parser.ParseFromString(parametrizedCommandText);
}
query.Timeout = Timeout;
try
{
var graphResult = ((SparqlResultSet)_processor.ProcessQuery(query)).Results;
lock (result)
{
result.AddRange(graphResult);
}
}
catch (RdfQueryTimeoutException)
{
state.Stop();
lock (result)
{
result.Clear();
}
}
}
/// <inheritdoc />
public virtual SparqlResultSet ExecuteSelect(IQuery sparqlQuery, out SparqlQueryVariables variables)
{
return((SparqlResultSet)((INativelyQueryableStore)Store).ExecuteQuery(GetSparqlQuery(sparqlQuery, out variables).ToString()));
}
