[tracker/wip/carlosg/sparql1.1: 14/80] libtracker-data: Set up union views

[Carlos Garnacho <carlosg src gnome org>]

commit 7ef42cb1c6bca8b50e89a7727c9d813b9e2afa6e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jul 7 23:45:32 2019 +0200

    libtracker-data: Set up union views

 src/libtracker-data/tracker-data-manager.c | 120 +++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
---
diff --git a/src/libtracker-data/tracker-data-manager.c b/src/libtracker-data/tracker-data-manager.c
index 15f4d976b..806a4e29a 100644
--- a/src/libtracker-data/tracker-data-manager.c
+++ b/src/libtracker-data/tracker-data-manager.c
@@ -3898,6 +3898,121 @@ tracker_data_manager_get_data_location (TrackerDataManager *manager)
        return manager->data_location ? g_object_ref (manager->data_location) : NULL;
 }
 
+static gboolean
+tracker_data_manager_update_union_views (TrackerDataManager  *manager,
+                                         TrackerDBInterface  *iface,
+                                         GError             **error)
+{
+       TrackerOntologies *ontologies = manager->ontologies;
+       TrackerClass **classes;
+       TrackerProperty **properties;
+       TrackerDBStatement *stmt;
+       guint i, n_classes, n_properties;
+       GError *inner_error = NULL;
+       GHashTableIter iter;
+       GHashTable *graphs;
+       gpointer graph_name, graph_id;
+       GString *str;
+
+       classes = tracker_ontologies_get_classes (ontologies, &n_classes);
+       properties = tracker_ontologies_get_properties (ontologies, &n_properties);
+       graphs = tracker_data_manager_get_graphs (manager, iface, error);
+
+       if (!graphs)
+               return FALSE;
+
+       for (i = 0; !inner_error && i < n_classes; i++) {
+               if (g_str_has_prefix (tracker_class_get_name (classes[i]), "xsd:"))
+                       continue;
+
+               stmt = tracker_db_interface_create_statement (iface, TRACKER_DB_STATEMENT_CACHE_TYPE_NONE, 
&inner_error,
+                                                             "DROP VIEW IF EXISTS temp.\"unionGraph_%s\"",
+                                                             tracker_class_get_name (classes[i]));
+               if (!stmt)
+                       break;
+
+               tracker_db_statement_execute (stmt, NULL);
+               g_object_unref (stmt);
+
+               str = g_string_new (NULL);
+               g_string_append_printf (str,
+                                       "CREATE VIEW temp.\"unionGraph_%s\" AS "
+                                       "SELECT 0 AS graph, * FROM \"main\".\"%s\" ",
+                                       tracker_class_get_name (classes[i]),
+                                       tracker_class_get_name (classes[i]));
+
+               g_hash_table_iter_init (&iter, graphs);
+               while (g_hash_table_iter_next (&iter, &graph_name, &graph_id)) {
+                       g_string_append_printf (str, "UNION ALL SELECT %d AS graph, * FROM \"%s\".\"%s\" ",
+                                               GPOINTER_TO_INT (graph_id),
+                                               (gchar *) graph_name,
+                                               tracker_class_get_name (classes[i]));
+               }
+
+               stmt = tracker_db_interface_create_statement (iface, TRACKER_DB_STATEMENT_CACHE_TYPE_NONE, 
&inner_error,
+                                                             "%s", str->str);
+               g_string_free (str, TRUE);
+               if (!stmt)
+                       break;
+
+               tracker_db_statement_execute (stmt, &inner_error);
+               g_object_unref (stmt);
+       }
+
+       for (i = 0; !inner_error && i < n_properties; i++) {
+               TrackerClass *service;
+
+               if (!tracker_property_get_multiple_values (properties[i]))
+                       continue;
+
+               service = tracker_property_get_domain (properties[i]);
+               stmt = tracker_db_interface_create_statement (iface, TRACKER_DB_STATEMENT_CACHE_TYPE_NONE, 
&inner_error,
+                                                             "DROP VIEW IF EXISTS temp.\"unionGraph_%s_%s\"",
+                                                             tracker_class_get_name (service),
+                                                             tracker_property_get_name (properties[i]));
+               if (!stmt)
+                       break;
+
+               tracker_db_statement_execute (stmt, NULL);
+               g_object_unref (stmt);
+
+               str = g_string_new (NULL);
+               g_string_append_printf (str,
+                                       "CREATE VIEW temp.\"unionGraph_%s_%s\" AS "
+                                       "SELECT 0 AS graph, * FROM \"main\".\"%s_%s\" ",
+                                       tracker_class_get_name (service),
+                                       tracker_property_get_name (properties[i]),
+                                       tracker_class_get_name (service),
+                                       tracker_property_get_name (properties[i]));
+
+               g_hash_table_iter_init (&iter, graphs);
+               while (g_hash_table_iter_next (&iter, &graph_name, &graph_id)) {
+                       g_string_append_printf (str, "UNION ALL SELECT %d AS graph, * FROM \"%s\".\"%s_%s\" ",
+                                               GPOINTER_TO_INT (graph_id),
+                                               (gchar *) graph_name,
+                                               tracker_class_get_name (service),
+                                               tracker_property_get_name (properties[i]));
+               }
+
+               stmt = tracker_db_interface_create_statement (iface, TRACKER_DB_STATEMENT_CACHE_TYPE_NONE, 
&inner_error,
+                                                             "%s", str->str);
+               g_string_free (str, TRUE);
+
+               if (!stmt)
+                       break;
+
+               tracker_db_statement_execute (stmt, &inner_error);
+               g_object_unref (stmt);
+       }
+
+       if (inner_error) {
+               g_propagate_error (error, inner_error);
+               return FALSE;
+       }
+
+       return TRUE;
+}
+
 TrackerDataManager *
 tracker_data_manager_new (TrackerDBManagerFlags   flags,
                           GFile                  *cache_location,
@@ -3985,6 +4100,11 @@ setup_interface_cb (TrackerDBManager   *db_manager,
                        }
                }
        }
+
+       if (!tracker_data_manager_update_union_views (data_manager, iface, &error)) {
+               g_critical ("Could not update union views: %s\n", error->message);
+               g_error_free (error);
+       }
 }
 
 static gboolean