diff rdf/SimpleSPARQLQuery.h @ 489:82ab61fa9223

* Reorganise our sparql queries on the basis that Redland must be
  available, not only optional.  So for anything querying the pool
  of data about plugins, we use a single datastore and model which
  is initialised at the outset by PluginRDFIndexer and then queried
  directly; for anything that "reads from a file" (e.g. loading
  annotations) we query directly using Rasqal, going to the
  datastore when we need additional plugin-related information.

  This may improve performance, but mostly it simplifies the code
  and fixes a serious issue with RDF import in the previous versions
  (namely that multiple sequential RDF imports would end up sharing
  the same RDF data pool!)

--- a/rdf/SimpleSPARQLQuery.h	Fri Nov 21 14:25:33 2008 +0000
+++ b/rdf/SimpleSPARQLQuery.h	Fri Nov 21 16:12:29 2008 +0000
@@ -37,9 +37,16 @@
     typedef std::map<QString, Value> KeyValueMap;
     typedef std::vector<KeyValueMap> ResultList;
 
-    SimpleSPARQLQuery(QString fromUri, QString query);
+    enum QueryType {
+        QueryFromModel,
+        QueryFromSingleSource
+    };
+
+    SimpleSPARQLQuery(QueryType type, QString query);
     ~SimpleSPARQLQuery();
 
+    static bool addSourceToModel(QString sourceUri);
+
     void setProgressReporter(ProgressReporter *reporter);
     bool wasCancelled() const;
     
@@ -50,21 +57,10 @@
 
     // Do a query and return the value for the given binding, from the
     // first result that has a value for it
-    static Value singleResultQuery(QString fromUri,
+    static Value singleResultQuery(QueryType type,
                                    QString query,
                                    QString binding);
 
-    enum BackEndPreference {
-        AutoSelectBackEnd,   // pick based on likely speed of available storage
-        DirectParserBackEnd, // use rasqal (simpler if seldom used)
-        DatastoreBackEnd,    // use redland (faster if version not too old)
-    };
-    /**
-     * Select the preferred query back end.  This should be called
-     * before any queries are made.  The default is AutoSelectBackEnd.
-     */
-    static void setBackEnd(BackEndPreference);
-
 protected:
     class Impl;
     Impl *m_impl;