[tracker/wip/carlosg/update-perf: 71/72] core: Avoid query for subclasses of a resource

[Carlos Garnacho <carlosg src gnome org>]

commit 7ddec5883982350fe5ac3baf593ad2196ae593b4
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Aug 20 17:35:54 2022 +0200

    core: Avoid query for subclasses of a resource
    
    In the slow paths of deleting a class, we must recursively delete
    all subclasses prior to the deletion of this class. We figure out
    the existing subclasses of a class for a given resource through a
    query, but we have this information right there.
    
    Use the types array, and recursively handle direct subclasses of
    the class being handled for deletion, so that things cascade properly
    and it mostly consists of a couple of array lookups as opposed to
    a database query.
    
    This should make these slow paths faster.

 src/libtracker-sparql/core/tracker-data-update.c | 54 ++++++------------------
 1 file changed, 13 insertions(+), 41 deletions(-)
---
diff --git a/src/libtracker-sparql/core/tracker-data-update.c 
b/src/libtracker-sparql/core/tracker-data-update.c
index fb2d071a8..0347877b9 100644
--- a/src/libtracker-sparql/core/tracker-data-update.c
+++ b/src/libtracker-sparql/core/tracker-data-update.c
@@ -2321,21 +2321,13 @@ cache_delete_resource_type_full (TrackerData   *data,
                                  gboolean       single_type,
                                  GError       **error)
 {
-       TrackerDBInterface *iface;
-       TrackerDBStatement *stmt;
-       TrackerProperty   **properties, *prop;
-       gboolean            found;
-       guint               i, p, n_props;
-       GError             *inner_error = NULL;
-       TrackerOntologies  *ontologies;
-       const gchar        *database;
-       GArray *res = NULL;
+       TrackerProperty **properties, *prop;
+       gboolean found;
+       guint i, j, p, n_props;
+       TrackerOntologies *ontologies;
        GValue gvalue = G_VALUE_INIT;
 
-       iface = tracker_data_manager_get_writable_db_interface (data->manager);
        ontologies = tracker_data_manager_get_ontologies (data->manager);
-       database = data->resource_buffer->graph->graph ?
-               data->resource_buffer->graph->graph : "main";
 
        if (!single_type) {
                if (strcmp (tracker_class_get_uri (class), TRACKER_PREFIX_RDFS "Resource") == 0) {
@@ -2369,42 +2361,22 @@ cache_delete_resource_type_full (TrackerData   *data,
 
                /* retrieve all subclasses we need to remove from the subject
                 * before we can remove the class specified as object of the statement */
-               stmt = tracker_db_interface_create_vstatement (iface, TRACKER_DB_STATEMENT_CACHE_TYPE_SELECT, 
&inner_error,
-                                                              "SELECT (SELECT Uri FROM Resource WHERE ID = 
subclass.ID) "
-                                                              "FROM \"%s\".\"rdfs:Resource_rdf:type\" AS 
type INNER JOIN \"%s\".\"rdfs:Class_rdfs:subClassOf\" AS subclass ON (type.\"rdf:type\" = subclass.ID) "
-                                                              "WHERE type.ID = ? AND 
subclass.\"rdfs:subClassOf\" = (SELECT ID FROM Resource WHERE Uri = ?)",
-                                                              database, database);
+               for (i = 0; i < data->resource_buffer->types->len; i++) {
+                       TrackerClass *type, **super_classes;
 
-               if (stmt) {
-                       tracker_db_statement_bind_int (stmt, 0, data->resource_buffer->id);
-                       tracker_db_statement_bind_text (stmt, 1, tracker_class_get_uri (class));
-                       res = tracker_db_statement_get_values (stmt,
-                                                              TRACKER_PROPERTY_TYPE_STRING,
-                                                              &inner_error);
-                       g_object_unref (stmt);
-               }
+                       type = g_ptr_array_index (data->resource_buffer->types, i);
+                       super_classes = tracker_class_get_super_classes (type);
 
-               if (res) {
-                       for (i = 0; i < res->len; i++) {
-                               const gchar *class_uri;
+                       for (j = 0; super_classes[j]; j++) {
+                               if (super_classes[j] != class)
+                                       continue;
 
-                               class_uri = g_value_get_string (&g_array_index (res, GValue, i));
-                               if (!cache_delete_resource_type_full (data, 
tracker_ontologies_get_class_by_uri (ontologies, class_uri),
-                                                                     FALSE, error)) {
-                                       g_array_unref (res);
+                               if (!cache_delete_resource_type_full (data, type, FALSE, error))
                                        return FALSE;
-                               }
                        }
-
-                       g_array_unref (res);
                }
 
-               if (inner_error) {
-                       g_propagate_prefixed_error (error,
-                                                   inner_error,
-                                                   "Deleting resource:");
-                       return FALSE;
-               }
+               /* Once done deleting subclasses, fall through */
        }
 
        /* Delete property values, only properties that: