protected override RdfBindingSet runTripleConstraints(java.util.List tripleConstraints,
name.levering.ryan.sparql.model.logic.ConstraintLogic.CallParams p)
{
if (DisableQuery)
return null;
RdfSourceWrapper s = (RdfSourceWrapper)p.source;
if (s.source is QueryableSource) {
QueryableSource qs = (QueryableSource)s.source;
QueryOptions opts = new QueryOptions();
opts.Limit = p.limit;
VariableList distinguishedVars = new VariableList();
VariableList undistinguishedVars = new VariableList();
opts.VariableKnownValues = new VarKnownValuesType();
Statement[] graph = new Statement[tripleConstraints.size()];
Hashtable varMap1 = new Hashtable();
Hashtable varMap2 = new Hashtable();
Entity metaField;
// In this case, we want to treat the meta fields of all of the statements
// in this group as bound by a single variable.
if (p.graphVariable != null) {
metaField = ToRes(p.graphVariable, p.knownValues, true, varMap1, varMap2, s, opts, distinguishedVars, undistinguishedVars, p.distinguishedVariables) as Entity;
// Otherwise, we are told what graph to use. If sourceDatasets is null,
// we are looking in the default graph.
} else if (p.sourceDatasets == null) {
/*if (p.defaultDatasets.size() == 0) {
metaField = Statement.DefaultMeta;
} else if (p.defaultDatasets.size() == 1) {
metaField = s.ToEntity((Value)p.defaultDatasets.iterator().next());
} else {
metaField = new SemWebVariable();
opts.VariableKnownValues[(Variable)metaField] = s.ToEntities((Value[])p.defaultDatasets.toArray(new Value[0]));
}*/
// For the default Graph, we always pass DefaultMeta.
metaField = Statement.DefaultMeta;
// Otherwise, we are looking in the indicated graphs.
} else {
if (p.sourceDatasets.size() == 0) {
metaField = new SemWebVariable();
} else if (p.sourceDatasets.size() == 1) {
metaField = s.ToEntity((Value)p.sourceDatasets.iterator().next());
} else {
metaField = new SemWebVariable();
opts.VariableKnownValues[(Variable)metaField] = s.ToEntities((Value[])p.sourceDatasets.toArray(new Value[0]));
}
}
for (int i = 0; i < tripleConstraints.size(); i++) {
TripleConstraintData triple = tripleConstraints.get(i) as TripleConstraintData;
if (triple == null) return null;
graph[i] = new Statement(null, null, null, null); // I don't understand why this should be necessary for a struct, but I get a null reference exception otherwise (yet, that didn't happen initially)
graph[i].Subject = ToRes(triple.getSubjectExpression(), p.knownValues, true, varMap1, varMap2, s, opts, distinguishedVars, undistinguishedVars, p.distinguishedVariables) as Entity;
graph[i].Predicate = ToRes(triple.getPredicateExpression(), p.knownValues, true, varMap1, varMap2, s, opts, distinguishedVars, undistinguishedVars, p.distinguishedVariables) as Entity;
graph[i].Object = ToRes(triple.getObjectExpression(), p.knownValues, false, varMap1, varMap2, s, opts, distinguishedVars, undistinguishedVars, p.distinguishedVariables);
graph[i].Meta = metaField;
if (graph[i].AnyNull) return new RdfBindingSetImpl();
if (!(graph[i].Subject is Variable) && !(graph[i].Predicate is Variable) && !(graph[i].Object is Variable) && !(graph[i].Meta is Variable))
return null; // we could use Contains(), but we'll just abandon the Query() path altogether
}
if (p.distinguishedVariables == null) {
opts.DistinguishedVariables = null;
} else if (distinguishedVars.Count > 0) {
opts.DistinguishedVariables = distinguishedVars;
} else if (undistinguishedVars.Count > 0) {
// we don't mean to make it distinguished, but we need at least one,
// and for now we'll just take the first
opts.DistinguishedVariables = new VariableList();
((VariableList)opts.DistinguishedVariables).Add(undistinguishedVars[0]);
} else {
// no variables!
return null;
}
opts.VariableLiteralFilters = new LitFilterMap();
foreach (DictionaryEntry kv in varMap1) {
if (p.knownFilters != null && p.knownFilters.containsKey(kv.Key)) {
LitFilterList filters = new LitFilterList();
for (java.util.Iterator iter = ((java.util.List)p.knownFilters.get(kv.Key)).iterator(); iter.hasNext(); )
filters.Add((LiteralFilter)iter.next());
opts.VariableLiteralFilters[(Variable)kv.Value] = filters;
}
}
// too expensive to do...
//if (!qs.MetaQuery(graph, opts).QuerySupported)
// return null; // TODO: We could also check if any part has NoData, we can abandon the query entirely
QueryResultBuilder builder = new QueryResultBuilder();
builder.varMap = varMap2;
builder.source = s;
qs.Query(graph, opts, builder);
return builder.bindings;
}
return null;
}
public override void Run(SelectableSource source, QueryResultSink resultsink)
{
if (!(query is SelectQuery))
throw new InvalidOperationException("Only SELECT queries are supported by this method (" + query.GetType() + ").");
// Perform the query
SelectQuery squery = (SelectQuery)query;
RdfSourceWrapper sourcewrapper = BindLogic(source);
RdfBindingSet results;
try {
results = squery.execute(sourcewrapper);
} catch (name.levering.ryan.sparql.common.QueryException e) {
throw new QueryExecutionException("Error executing query: " + e.Message, e);
}
// Prepare binding objects
java.util.List vars = results.getVariables();
SparqlVariable[] svars = new SparqlVariable[vars.size()];
SemWebVariable[] vars2 = new SemWebVariable[vars.size()];
for (int i = 0; i < svars.Length; i++) {
svars[i] = (SparqlVariable)vars.get(i);
vars2[i] = new SemWebVariable(svars[i].getName());
}
// Initialize the result sink
resultsink.Init(vars2); // set distinct and ordered
// Set the comments
resultsink.AddComments(queryString + "\n");
resultsink.AddComments(sourcewrapper.GetLog());
// Iterate the bindings
java.util.Iterator iter = results.iterator();
long ctr = -1, ctr2 = 0;
while (iter.hasNext()) {
RdfBindingRow row = (RdfBindingRow)iter.next();
// Since SPARQL processing may be lazy-delayed,
// add any new comments that might have been logged.
resultsink.AddComments(sourcewrapper.GetLog());
ctr++;
if (ctr < ReturnStart && ReturnStart != -1) continue;
Resource[] bindings = new Resource[vars2.Length];
for (int i = 0; i < bindings.Length; i++) {
Resource r = sourcewrapper.ToResource(row.getValue(svars[i]));
r = sourcewrapper.Persist(r);
bindings[i] = r;
}
resultsink.AddComments(sourcewrapper.GetLog());
resultsink.Add(new VariableBindings(vars2, bindings));
ctr2++;
if (ctr2 >= ReturnLimit && ReturnLimit != -1) break;
}
resultsink.AddComments(sourcewrapper.GetLog());
// Close the result sink.
resultsink.Finished();
}
