[tracker/wip/carlosg/sparql1.1: 181/201] libtracker-data: Update union views selectively

[Carlos Garnacho <carlosg src gnome org>]

commit 6510a14025856d2477f5c5dc74866fbb00570dbe
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Sep 7 13:13:40 2019 +0200

    libtracker-data: Update union views selectively
    
    Keep track of the union views required by a query, and update those
    specifically (if the database generation bumped in between).

 src/libtracker-data/tracker-data-manager.c |  9 +--------
 src/libtracker-data/tracker-sparql.c       | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 8 deletions(-)
---
diff --git a/src/libtracker-data/tracker-data-manager.c b/src/libtracker-data/tracker-data-manager.c
index 2c62c5cb6..70c7a2845 100644
--- a/src/libtracker-data/tracker-data-manager.c
+++ b/src/libtracker-data/tracker-data-manager.c
@@ -4362,15 +4362,8 @@ update_interface_cb (TrackerDBManager   *db_manager,
                        /* This is where we bump the generation for the readonly case, in response to
                         * tables being attached or detached due to graph changes.
                         */
-                       if (readonly && changed) {
+                       if (readonly && changed)
                                data_manager->generation++;
-                               if (!tracker_data_manager_update_union_views (data_manager, iface,
-                                                                             NULL, &error)) {
-                                       g_critical ("Could not update union views: %s\n",
-                                                   error->message);
-                                       g_error_free (error);
-                               }
-                       }
                } else {
                        g_critical ("Could not update attached databases: %s\n",
                                    error->message);
diff --git a/src/libtracker-data/tracker-sparql.c b/src/libtracker-data/tracker-sparql.c
index 26e852969..4e507d99c 100644
--- a/src/libtracker-data/tracker-sparql.c
+++ b/src/libtracker-data/tracker-sparql.c
@@ -132,6 +132,7 @@ struct _TrackerSparql
        gboolean cacheable;
 
        GHashTable *parameters;
+       GHashTable *union_views;
 
        GPtrArray *anon_graphs;
        GPtrArray *named_graphs;
@@ -179,6 +180,7 @@ tracker_sparql_finalize (GObject *object)
        g_hash_table_destroy (sparql->prefix_map);
        g_hash_table_destroy (sparql->parameters);
        g_hash_table_destroy (sparql->cached_bindings);
+       g_clear_pointer (&sparql->union_views, g_hash_table_unref);
 
        if (sparql->sql)
                tracker_string_builder_free (sparql->sql);
@@ -577,6 +579,11 @@ _prepend_path_element (TrackerSparql      *sparql,
                        table_name = g_strdup_printf ("\"unionGraph_%s\"",
                                                      tracker_property_get_table_name 
(path_elem->data.property));
                        graph_column = g_strdup ("graph");
+
+                       if (sparql->union_views) {
+                               g_hash_table_add (sparql->union_views,
+                                                 g_strdup (tracker_property_get_table_name 
(path_elem->data.property)));
+                       }
                } else {
                        const gchar *graph;
 
@@ -688,6 +695,7 @@ _prepend_path_element (TrackerSparql      *sparql,
                }
 
                _append_string (sparql, ") ");
+               g_clear_pointer (&sparql->union_views, g_hash_table_unref);
                break;
        case TRACKER_PATH_OPERATOR_INTERSECTION:
                _append_string_printf (sparql,
@@ -1830,6 +1838,7 @@ _end_triples_block (TrackerSparql  *sparql,
                        _append_string (sparql,
                                        "(SELECT subject AS ID, predicate, "
                                        "object, object_type, graph FROM tracker_triples ");
+                       g_clear_pointer (&sparql->union_views, g_hash_table_unref);
 
                        if (table->graph) {
                                _append_graph_checks (sparql, "graph",
@@ -1882,6 +1891,9 @@ _end_triples_block (TrackerSparql  *sparql,
                                }
 
                                _append_string (sparql, ") ");
+
+                               if (sparql->union_views)
+                                       g_hash_table_add (sparql->union_views, g_strdup 
(table->sql_db_tablename));
                        }
                }
 
@@ -2509,6 +2521,8 @@ translate_DescribeQuery (TrackerSparql  *sparql,
                        "FROM tracker_triples "
                        "WHERE object IS NOT NULL AND subject IN (");
 
+       g_clear_pointer (&sparql->union_views, g_hash_table_unref);
+
        if (_accept (sparql, RULE_TYPE_LITERAL, LITERAL_GLOB)) {
                glob = TRUE;
        } else {
@@ -6580,6 +6594,10 @@ handle_property_function (TrackerSparql    *sparql,
        if (tracker_token_is_empty (&sparql->current_state.graph)) {
                _append_string_printf (sparql, "FROM \"unionGraph_%s\" ",
                                       tracker_property_get_table_name (property));
+               if (sparql->union_views) {
+                       g_hash_table_add (sparql->union_views,
+                                         g_strdup (tracker_property_get_table_name (property)));
+               }
        } else {
                _append_string_printf (sparql, "FROM \"%s\".\"%s\" ",
                                       tracker_token_get_idstring (&sparql->current_state.graph),
@@ -8325,6 +8343,8 @@ tracker_sparql_init (TrackerSparql *sparql)
                                                         g_free, g_object_unref);
        sparql->parameters = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                    g_free, g_object_unref);
+       sparql->union_views = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                                    g_free, NULL);
        sparql->var_names = g_ptr_array_new_with_free_func (g_free);
        sparql->var_types = g_array_new (FALSE, FALSE, sizeof (TrackerPropertyType));
        sparql->anon_graphs = g_ptr_array_new_with_free_func (g_free);
@@ -8370,6 +8390,10 @@ prepare_query (TrackerSparql         *sparql,
        gchar *query;
        guint i;
 
+       if (!tracker_data_manager_update_union_views (sparql->data_manager, iface,
+                                                     sparql->union_views, error))
+               return NULL;
+
        query = tracker_string_builder_to_string (str);
        stmt = tracker_db_interface_create_statement (iface,
                                                      cached ?