Merge pull request #11 from dwhitney/service-query-options

Service query options

lib/src/lib.rs

@@ -27,8 +27,9 @@
 //! assert_eq!(vec![quad], results.unwrap());
 //!
 //! // SPARQL query
-//! let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default()).unwrap();
+//! let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", None).unwrap();
-//! let results = prepared_query.exec().unwrap();
+//! let options = QueryOptions::default();
+//! let results = prepared_query.exec(&options).unwrap();
 //! if let QueryResult::Bindings(results) = results {
 //!     assert_eq!(results.into_values_iter().next().unwrap().unwrap()[0], Some(ex.into()));
 //! }

lib/src/repository.rs

@@ -1,5 +1,5 @@
 use crate::model::*;
-use crate::sparql::{PreparedQuery, QueryOptions};
+use crate::sparql::{GraphPattern, PreparedQuery};
 use crate::{DatasetSyntax, GraphSyntax, Result};
 use std::io::BufRead;
 
@@ -30,8 +30,9 @@ use std::io::BufRead;
 /// assert_eq!(vec![quad], results.unwrap());
 ///
 /// // SPARQL query
-/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default()).unwrap();
+/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", None).unwrap();
-/// let results = prepared_query.exec().unwrap();
+/// let options = QueryOptions::default();
+/// let results = prepared_query.exec(&options).unwrap();
 /// if let QueryResult::Bindings(results) = results {
 ///     assert_eq!(results.into_values_iter().next().unwrap().unwrap()[0], Some(ex.into()));
 /// }
@@ -75,13 +76,21 @@ pub trait RepositoryConnection: Clone {
     /// connection.insert(&Quad::new(ex.clone(), ex.clone(), ex.clone(), None));
     ///
     /// // SPARQL query
-    /// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default()).unwrap();
+    /// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", None).unwrap();
-    /// let results = prepared_query.exec().unwrap();
+    /// let options = QueryOptions::default();
+    /// let results = prepared_query.exec(&options).unwrap();
     /// if let QueryResult::Bindings(results) = results {
     ///     assert_eq!(results.into_values_iter().next().unwrap().unwrap()[0], Some(ex.into()));
     /// }
     /// ```
-    fn prepare_query(&self, query: &str, options: QueryOptions) -> Result<Self::PreparedQuery>;
+    fn prepare_query<'a>(&'a self, query: &str, base_iri: Option<&'a str>) -> Result<Self::PreparedQuery>;
+
+    /// This is similar to `prepare_query`, but useful if a SPARQL query has already been parsed, which is the case when building `ServiceHandler`s for federated queries with `SERVICE` clauses. For examples, look in the tests.
+    fn prepare_query_from_pattern<'a>(
+        &'a self,
+        graph_pattern: &'a GraphPattern,
+        base_iri: Option<&str>,
+    ) -> Result<Self::PreparedQuery>;
 
     /// Retrieves quads with a filter on each quad component
     ///

lib/src/sparql/mod.rs

@@ -9,6 +9,7 @@ mod plan;
 mod plan_builder;
 mod xml_results;
 
+use crate::model::NamedNode;
 use crate::sparql::algebra::QueryVariants;
 use crate::sparql::eval::SimpleEvaluator;
 use crate::sparql::parser::read_sparql_query;
@@ -17,8 +18,11 @@ use crate::sparql::plan::{DatasetView, PlanNode};
 use crate::sparql::plan_builder::PlanBuilder;
 use crate::store::StoreConnection;
 use crate::Result;
+use failure::format_err;
+use rio_api::iri::Iri;
 use std::fmt;
 
+pub use crate::sparql::algebra::GraphPattern;
 pub use crate::sparql::model::BindingsIterator;
 pub use crate::sparql::model::QueryResult;
 pub use crate::sparql::model::QueryResultSyntax;
@@ -27,7 +31,7 @@ pub use crate::sparql::model::Variable;
 /// A prepared [SPARQL query](https://www.w3.org/TR/sparql11-query/)
 pub trait PreparedQuery {
     /// Evaluates the query and returns its results
-    fn exec(&self) -> Result<QueryResult>;
+    fn exec<'a>(&'a self, options: &'a QueryOptions<'a>) -> Result<QueryResult<'a>>;
 }
 
 /// An implementation of `PreparedQuery` for internal use
@@ -54,11 +58,11 @@ enum SimplePreparedQueryAction<S: StoreConnection> {
     },
 }
 
-impl<S: StoreConnection> SimplePreparedQuery<S> {
+impl<'a, S: StoreConnection + 'a> SimplePreparedQuery<S> {
-    pub(crate) fn new(connection: S, query: &str, options: QueryOptions) -> Result<Self> {
+    pub(crate) fn new(connection: S, query: &str, base_iri: Option<&'a str>) -> Result<Self> {
-        let dataset = DatasetView::new(connection, options.default_graph_as_union);
+        let dataset = DatasetView::new(connection);
         //TODO avoid inserting terms in the Repository StringStore
-        Ok(Self(match read_sparql_query(query, options.base_iri)? {
+        Ok(Self(match read_sparql_query(query, base_iri)? {
             QueryVariants::Select {
                 algebra,
                 dataset: _,
@@ -112,35 +116,67 @@ impl<S: StoreConnection> SimplePreparedQuery<S> {
             }
         }))
     }
+
+    /// Builds SimplePreparedQuery from an existing `GraphPattern`. This is used to support federated queries via `SERVICE` clauses
+    pub(crate) fn new_from_pattern(
+        connection: S,
+        pattern: &GraphPattern,
+        base_iri: Option<&'a str>
+    ) -> Result<Self> {
+        let dataset = DatasetView::new(connection);
+        let (plan, variables) = PlanBuilder::build(dataset.encoder(), pattern)?;
+        let base_iri = base_iri.map(|str_iri| Iri::parse(str_iri.to_string()));
+        match base_iri {
+            Some(Err(_)) => Err(format_err!("Failed to parse base_iri")),
+            Some(Ok(base_iri)) =>  
+                Ok(Self(SimplePreparedQueryAction::Select {
+                    plan,
+                    variables,
+                    evaluator: SimpleEvaluator::new(dataset, Some(base_iri)),
+                })),
+            None =>  
+                Ok(Self(SimplePreparedQueryAction::Select {
+                    plan,
+                    variables,
+                    evaluator: SimpleEvaluator::new(dataset, None),
+                }))
+        }
+        
+    }
 }
 
 impl<S: StoreConnection> PreparedQuery for SimplePreparedQuery<S> {
-    fn exec(&self) -> Result<QueryResult<'_>> {
+    fn exec<'a>(&'a self, options: &'a QueryOptions<'a>) -> Result<QueryResult<'a>> {
         match &self.0 {
             SimplePreparedQueryAction::Select {
                 plan,
                 variables,
                 evaluator,
-            } => evaluator.evaluate_select_plan(&plan, &variables),
+            } => evaluator.evaluate_select_plan(&plan, &variables, options),
             SimplePreparedQueryAction::Ask { plan, evaluator } => {
-                evaluator.evaluate_ask_plan(&plan)
+                evaluator.evaluate_ask_plan(&plan, options)
             }
             SimplePreparedQueryAction::Construct {
                 plan,
                 construct,
                 evaluator,
-            } => evaluator.evaluate_construct_plan(&plan, &construct),
+            } => evaluator.evaluate_construct_plan(&plan, &construct, &options),
             SimplePreparedQueryAction::Describe { plan, evaluator } => {
-                evaluator.evaluate_describe_plan(&plan)
+                evaluator.evaluate_describe_plan(&plan, &options)
             }
         }
     }
 }
 
+pub trait ServiceHandler {
+    fn handle<'a>(&'a self, node: NamedNode) -> Option<(fn(GraphPattern) -> Result<BindingsIterator<'a>>)>;
+}
+
 /// Options for SPARQL query parsing and evaluation like the query base IRI
 pub struct QueryOptions<'a> {
     pub(crate) base_iri: Option<&'a str>,
     pub(crate) default_graph_as_union: bool,
+    pub(crate) service_handler: Option<Box<dyn ServiceHandler>>,
 }
 
 impl<'a> Default for QueryOptions<'a> {
@@ -148,6 +184,7 @@ impl<'a> Default for QueryOptions<'a> {
         Self {
             base_iri: None,
             default_graph_as_union: false,
+            service_handler: None as Option<Box<dyn ServiceHandler>>,
         }
     }
 }
@@ -164,6 +201,12 @@ impl<'a> QueryOptions<'a> {
         self.default_graph_as_union = true;
         self
     }
+
+    /// Consider the union of all graphs in the repository as the default graph
+    pub fn with_service_handler(mut self, service_handler: Box<dyn ServiceHandler>) -> Self {
+        self.service_handler = Some(service_handler);
+        self
+    }
 }
 
 /// A parsed [SPARQL query](https://www.w3.org/TR/sparql11-query/)

lib/src/sparql/model.rs

@@ -116,7 +116,7 @@ pub struct BindingsIterator<'a> {
 }
 
 impl<'a> BindingsIterator<'a> {
-    pub(crate) fn new(
+    pub fn new(
         variables: Vec<Variable>,
         iter: Box<dyn Iterator<Item = Result<Vec<Option<Term>>>> + 'a>,
     ) -> Self {

lib/src/sparql/plan.rs

@@ -1,3 +1,5 @@
+use crate::sparql::GraphPattern;
+use crate::sparql::model::Variable;
 use crate::sparql::eval::StringOrStoreString;
 use crate::store::numeric_encoder::{
     EncodedQuad, EncodedTerm, Encoder, MemoryStrStore, StrContainer, StrLookup,
@@ -16,6 +18,13 @@ pub enum PlanNode {
     StaticBindings {
         tuples: Vec<EncodedTuple>,
     },
+    Service {
+        service_name: PatternValue,
+        variables: Vec<Variable>,
+        child: Box<PlanNode>,
+        graph_pattern: GraphPattern,
+        silent: bool,
+    },
     QuadPatternJoin {
         child: Box<PlanNode>,
         subject: PatternValue,
@@ -161,6 +170,7 @@ impl PlanNode {
                 set.insert(*position);
                 child.add_variables(set);
             }
+            PlanNode::Service { child, .. } => child.add_variables(set),
             PlanNode::Sort { child, .. } => child.add_variables(set),
             PlanNode::HashDeduplicate { child } => child.add_variables(set),
             PlanNode::Skip { child, .. } => child.add_variables(set),
@@ -463,15 +473,13 @@ pub enum TripleTemplateValue {
 pub struct DatasetView<S: StoreConnection> {
     store: S,
     extra: RefCell<MemoryStrStore>,
-    default_graph_as_union: bool,
 }
 
 impl<S: StoreConnection> DatasetView<S> {
-    pub fn new(store: S, default_graph_as_union: bool) -> Self {
+    pub fn new(store: S) -> Self {
         Self {
             store,
             extra: RefCell::new(MemoryStrStore::default()),
-            default_graph_as_union,
         }
     }
 
@@ -481,6 +489,7 @@ impl<S: StoreConnection> DatasetView<S> {
         predicate: Option<EncodedTerm>,
         object: Option<EncodedTerm>,
         graph_name: Option<EncodedTerm>,
+        default_graph_as_union: bool,
     ) -> Box<dyn Iterator<Item = Result<EncodedQuad>> + 'a> {
         if graph_name == None {
             Box::new(
@@ -491,7 +500,7 @@ impl<S: StoreConnection> DatasetView<S> {
                         Ok(quad) => quad.graph_name != ENCODED_DEFAULT_GRAPH,
                     }),
             )
-        } else if graph_name == Some(ENCODED_DEFAULT_GRAPH) && self.default_graph_as_union {
+        } else if graph_name == Some(ENCODED_DEFAULT_GRAPH) && default_graph_as_union {
             Box::new(
                 self.store
                     .quads_for_pattern(subject, predicate, object, None)

lib/src/sparql/plan_builder.rs

@@ -103,11 +103,17 @@ impl<E: Encoder> PlanBuilder<E> {
                 left: Box::new(self.build_for_graph_pattern(a, variables, graph_name)?),
                 right: Box::new(self.build_for_graph_pattern(b, variables, graph_name)?),
             },
-            GraphPattern::Service(_n, _p, _s) => {
+            GraphPattern::Service(n, p, s) => {
-                return Err(format_err!(
+                let service_name = self.pattern_value_from_named_node_or_variable(n, variables)?;
-                    "SPARQL SERVICE clauses are not implemented yet"
+                let graph_pattern = *p.clone();
-                ))
+                PlanNode::Service {
+                    service_name,
+                    variables: variables.clone(),
+                    child: Box::new(self.build_for_graph_pattern(p, variables, service_name)?),
+                    graph_pattern,
+                    silent: *s,
                 }
+            },
             GraphPattern::AggregateJoin(GroupPattern(key, p), aggregates) => {
                 let mut inner_variables = key.clone();
                 let inner_graph_name =

lib/src/store/memory.rs

@@ -29,8 +29,9 @@ use std::sync::{PoisonError, RwLock, RwLockReadGuard, RwLockWriteGuard};
 /// assert_eq!(vec![quad], results.unwrap());
 ///
 /// // SPARQL query
-/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default()).unwrap();
+/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", None).unwrap();
-/// let results = prepared_query.exec().unwrap();
+/// let options = QueryOptions::default();
+/// let results = prepared_query.exec(&options).unwrap();
 /// if let QueryResult::Bindings(results) = results {
 ///     assert_eq!(results.into_values_iter().next().unwrap().unwrap()[0], Some(ex.into()));
 /// }

lib/src/store/mod.rs

@@ -5,12 +5,13 @@ pub(crate) mod numeric_encoder;
 #[cfg(feature = "rocksdb")]
 mod rocksdb;
 
+pub use crate::sparql::GraphPattern;
 pub use crate::store::memory::MemoryRepository;
 #[cfg(feature = "rocksdb")]
 pub use crate::store::rocksdb::RocksDbRepository;
 
 use crate::model::*;
-use crate::sparql::{QueryOptions, SimplePreparedQuery};
+use crate::sparql::{SimplePreparedQuery};
 use crate::store::numeric_encoder::*;
 use crate::{DatasetSyntax, GraphSyntax, RepositoryConnection, Result};
 use rio_api::parser::{QuadsParser, TriplesParser};
@@ -71,8 +72,8 @@ impl<S: StoreConnection> From<S> for StoreRepositoryConnection<S> {
 impl<S: StoreConnection> RepositoryConnection for StoreRepositoryConnection<S> {
     type PreparedQuery = SimplePreparedQuery<S>;
 
-    fn prepare_query(&self, query: &str, options: QueryOptions) -> Result<SimplePreparedQuery<S>> {
+    fn prepare_query<'a>(&self, query: &str, base_iri: Option<&'a str>) -> Result<SimplePreparedQuery<S>> {
-        SimplePreparedQuery::new(self.inner.clone(), query, options) //TODO: avoid clone
+        SimplePreparedQuery::new(self.inner.clone(), query, base_iri) //TODO: avoid clone
     }
 
     fn quads_for_pattern<'a>(
@@ -96,6 +97,15 @@ impl<S: StoreConnection> RepositoryConnection for StoreRepositoryConnection<S> {
         )
     }
 
+
+    fn prepare_query_from_pattern<'a>(
+        &'a self,
+        pattern: &GraphPattern,
+        base_iri: Option<&'a str>
+    ) -> Result<Self::PreparedQuery> {
+        SimplePreparedQuery::new_from_pattern(self.inner.clone(), pattern, base_iri) //TODO: avoid clone
+    }
+
     fn load_graph(
         &mut self,
         reader: impl BufRead,

lib/src/store/rocksdb.rs

@@ -40,8 +40,9 @@ use std::str;
 /// assert_eq!(vec![quad], results.unwrap());
 ///
 /// // SPARQL query
-/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default()).unwrap();
+/// let options = QueryOptions::default();
-/// let results = prepared_query.exec().unwrap();
+/// let prepared_query = connection.prepare_query("SELECT ?s WHERE { ?s ?p ?o }", None).unwrap();
+/// let results = prepared_query.exec(&options).unwrap();
 /// if let QueryResult::Bindings(results) = results {
 ///     assert_eq!(results.into_values_iter().next().unwrap().unwrap()[0], Some(ex.into()));
 /// }

lib/tests/service_test_cases.rs

@@ -0,0 +1,240 @@
+use rudf::model::*;
+use rudf::{GraphSyntax, Repository, RepositoryConnection, MemoryRepository, Result};
+use rudf::sparql::{BindingsIterator, GraphPattern, PreparedQuery, QueryOptions, QueryResult, ServiceHandler};
+use failure::format_err;
+use std::io::BufRead;
+
+
+
+#[test]
+fn simple_service_test() {
+
+  struct TestServiceHandler;
+  impl ServiceHandler for TestServiceHandler {
+    fn handle<'a>(&'a self, _named_node: NamedNode) -> Option<(fn(GraphPattern) -> Result<BindingsIterator<'a>>)> {
+      fn pattern_handler<'a>(graph_pattern: GraphPattern) -> Result<BindingsIterator<'a>> {
+        let triples = b"<http://example.com/s> <http://example.com/p> <http://example.com/o> .".as_ref();
+        do_pattern(triples, graph_pattern, QueryOptions::default())
+      };
+      Some(pattern_handler)
+    }
+  }
+
+  let query = r#"
+  SELECT ?s ?p ?o
+  WHERE
+    { 
+      SERVICE <http://service1.org>
+      { ?s ?p ?o
+      }
+   }
+  "#.to_string();
+
+
+  let options = QueryOptions::default().with_service_handler(Box::new(TestServiceHandler));
+  let results = do_query(b"".as_ref(), query, options).unwrap();
+  let collected = results.into_values_iter().map(move |b| b.unwrap()).collect::<Vec<_>>();
+  let solution = vec![
+      vec![ Some(ex(String::from("s"))), Some(ex(String::from("p"))), Some(ex(String::from("o"))) ],
+  ];
+  assert_eq!(collected, solution);
+  
+}
+
+
+#[test]
+fn two_service_test() {
+
+  #[derive(Clone,Copy)]
+  struct TwoServiceTest;
+  impl ServiceHandler for TwoServiceTest {
+      fn handle<'a>(&'a self, named_node: NamedNode) -> Option<(fn(GraphPattern) -> Result<BindingsIterator<'a>>)> {
+          let service1 = NamedNode::parse("http://service1.org").unwrap();
+          let service2 = NamedNode::parse("http://service2.org").unwrap();
+          if named_node == service1 { Some(TwoServiceTest::handle_service1) }
+          else if named_node == service2 { Some(TwoServiceTest::handle_service2) }
+          else { None } 
+      }
+  }
+
+
+  impl TwoServiceTest {
+
+    fn handle_service1<'a>(graph_pattern: GraphPattern) -> Result<BindingsIterator<'a>> {
+      let triples = br#"
+        <http://example.com/bob> <http://xmlns.com/foaf/0.1/name> "Bob" .
+        <http://example.com/alice> <http://xmlns.com/foaf/0.1/name> "Alice" .
+        "#.as_ref();
+      do_pattern(triples, graph_pattern, QueryOptions::default())
+    }
+
+    fn handle_service2<'a>(graph_pattern: GraphPattern) -> Result<BindingsIterator<'a>> {
+      let triples = br#"
+        <http://example.com/bob> <http://xmlns.com/foaf/0.1/mbox> <mailto:bob@example.com> .
+        <http://example.com/alice> <http://xmlns.com/foaf/0.1/mbox> <mailto:alice@example.com> .
+        "#.as_ref();
+      do_pattern(triples, graph_pattern, QueryOptions::default())
+    }
+
+  }
+
+  let query = r#"
+  PREFIX foaf: <http://xmlns.com/foaf/0.1/>
+  SELECT ?name ?mbox 
+  WHERE
+    { 
+      SERVICE <http://service1.org>
+      { ?s foaf:name ?name
+      }
+
+      SERVICE <http://service2.org>
+      { ?s foaf:mbox ?mbox
+      }
+    }
+  ORDER BY ?name
+  "#.to_string();
+
+  let options = QueryOptions::default().with_service_handler(Box::new(TwoServiceTest));
+  let results = do_query(b"".as_ref(), query, options).unwrap();
+  let collected = results.into_values_iter().map(move |b| b.unwrap()).collect::<Vec<_>>();
+  let solution = vec![
+      vec![ Some(literal("Alice".to_string())), Some(mailto("alice@example.com".to_string())) ],
+      vec![ Some(literal("Bob".to_string())), Some(mailto("bob@example.com".to_string())) ],
+    ];
+  assert_eq!(collected, solution);
+}
+
+#[test]
+fn silent_service_empty_set_test() {
+
+  #[derive(Clone,Copy)]
+  struct ServiceTest;
+  impl ServiceHandler for ServiceTest {
+      fn handle<'a>(&'a self, _named_node: NamedNode) -> Option<(fn(GraphPattern) -> Result<BindingsIterator<'a>>)> {
+         Some(ServiceTest::handle_service) 
+      }
+  }
+
+  impl ServiceTest {
+    fn handle_service<'a>(_graph_pattern: GraphPattern) -> Result<BindingsIterator<'a>> {
+      Err(format_err!("This is supposed to fail"))
+    }
+  }
+
+  let query = r#"
+  PREFIX foaf: <http://xmlns.com/foaf/0.1/>
+  SELECT ?name ?mbox 
+  WHERE
+    { 
+      SERVICE SILENT <http://service1.org>
+      { ?s foaf:name ?name
+      }
+      
+    }
+  ORDER BY ?name
+  "#.to_string();
+  
+  let triples = b"".as_ref();
+  let options = QueryOptions::default().with_service_handler(Box::new(ServiceTest));
+  let results = do_query(triples, query, options).unwrap();
+  let collected = results.into_values_iter().map(move |b| b.unwrap()).collect::<Vec<_>>();
+  println!("Collected: {:?}", collected);
+  assert_eq!(collected.len(), 0);
+}
+
+#[test]
+fn non_silent_service_test() {
+
+  #[derive(Clone,Copy)]
+  struct ServiceTest;
+  impl ServiceHandler for ServiceTest {
+      fn handle<'a>(&'a self, _named_node: NamedNode) -> Option<(fn(GraphPattern) -> Result<BindingsIterator<'a>>)> {
+         Some(ServiceTest::handle_service) 
+      }
+  }
+
+  impl ServiceTest {
+    fn handle_service<'a>(_graph_pattern: GraphPattern) -> Result<BindingsIterator<'a>> {
+      Err(format_err!("This is supposed to fail"))
+    }
+  }
+
+  let query = r#"
+  PREFIX foaf: <http://xmlns.com/foaf/0.1/>
+  SELECT ?name
+  WHERE
+    { 
+      SERVICE <http://service1.org>
+      { ?s foaf:name ?name
+      }
+      
+    }
+  ORDER BY ?name
+  "#.to_string();
+  
+  let triples = b"".as_ref();
+  let options = QueryOptions::default().with_service_handler(Box::new(ServiceTest));
+  let results = do_query(triples, query, options).unwrap();
+  let result = results.into_values_iter().next();
+  match result {
+    Some(Err(_)) => assert_eq!(true, true),
+    _ => assert_eq!(true, false, "This should have been an error since the service fails"),
+  }
+}
+
+fn ex(id: String) -> Term {
+  Term::NamedNode(NamedNode::parse(format!("http://example.com/{}", &id)).unwrap())
+}
+
+fn mailto(id: String) -> Term {
+  Term::NamedNode(NamedNode::parse(format!("mailto:{}", &id)).unwrap())
+}
+
+fn literal(str: String) -> Term {
+  Term::Literal(Literal::new_simple_literal(str))
+}
+
+fn make_repository(reader: impl BufRead) -> Result<MemoryRepository> {
+  let repository = MemoryRepository::default();
+  let mut connection = repository.connection()?;
+  connection.load_graph(reader, GraphSyntax::NTriples, None, None).unwrap();
+  Ok(repository)
+}
+
+fn query_repository<'a>(repository: MemoryRepository, query: String, options: QueryOptions<'a>) -> Result<BindingsIterator<'a>> {
+  let connection = repository.connection()?;
+  let prepared_query = connection.prepare_query(&query, None)?;
+  let result = prepared_query.exec(&options)?;
+  match result {
+    QueryResult::Bindings(iterator) => {
+      let (varaibles, iter) = iterator.destruct();
+      let collected = iter.collect::<Vec<_>>();
+      Ok(BindingsIterator::new(varaibles, Box::new(collected.into_iter())))
+    },
+    _ => Err(format_err!("Excpected bindings but got another QueryResult"))
+  }
+} 
+
+fn pattern_repository<'a>(repository: MemoryRepository, pattern: GraphPattern, options: QueryOptions<'a>) -> Result<BindingsIterator<'a>> {
+  let connection = repository.connection()?;
+  let prepared_query = connection.prepare_query_from_pattern(&pattern, None)?;
+  let result = prepared_query.exec(&options)?;
+  match result {
+    QueryResult::Bindings(iterator) => {
+      let (varaibles, iter) = iterator.destruct();
+      let collected = iter.collect::<Vec<_>>();
+      Ok(BindingsIterator::new(varaibles, Box::new(collected.into_iter())))
+    }
+    _ => Err(format_err!("Excpected bindings but got another QueryResult"))
+  }
+}
+
+fn do_query<'a>(reader: impl BufRead, query: String, options: QueryOptions<'a>) -> Result<BindingsIterator<'a>> {
+  let repository = make_repository(reader)?;
+  query_repository(repository, query, options)
+}
+
+fn do_pattern<'a>(reader: impl BufRead, pattern: GraphPattern, options: QueryOptions<'a>) -> Result<BindingsIterator<'a>> {
+  let repository = make_repository(reader)?;
+  pattern_repository(repository, pattern, options)
+}

lib/tests/sparql_test_cases.rs

@@ -158,13 +158,13 @@ fn sparql_w3c_query_evaluation_testsuite() -> Result<()> {
             }
             match repository
                 .connection()?
-                .prepare_query(&read_file_to_string(&test.query)?, QueryOptions::default().with_base_iri(&test.query))
+                .prepare_query(&read_file_to_string(&test.query)?, Some(&test.query))
             {
                 Err(error) => Err(format_err!(
                     "Failure to parse query of {} with error: {}",
                     test, error
                 )),
-                Ok(query) => match query.exec() {
+                Ok(query) => match query.exec(&QueryOptions::default()) {
                     Err(error) => Err(format_err!(
                         "Failure to execute query of {} with error: {}",
                         test, error

server/src/main.rs

@@ -148,9 +148,10 @@ fn evaluate_sparql_query<R: RepositoryConnection>(
     request: &Request,
 ) -> Response {
     //TODO: stream
-    match connection.prepare_query(query, QueryOptions::default()) {
+    let options = QueryOptions::default();
+    match connection.prepare_query(query, None) {
         Ok(query) => {
-            let results = query.exec().unwrap();
+            let results = query.exec(&options).unwrap();
             if let QueryResult::Graph(_) = results {
                 let supported_formats = [
                     GraphSyntax::NTriples.media_type(),