[tracker/wip/carlosg/data-update-cleanups: 5/11] libtracker-data: Streamline deletion of all values in a multi-valued property

[Carlos Garnacho <carlosg src gnome org>]

commit d37fc03c8e17f404e91f7b29e71805a4ae033736
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Apr 25 16:24:27 2020 +0200

    libtracker-data: Streamline deletion of all values in a multi-valued property
    
    Instead of fetching all values, and deleting those one by one, we can flag
    the operation so that all values are deleted at once.

 src/libtracker-data/tracker-data-update.c | 177 ++++++++----------------------
 1 file changed, 46 insertions(+), 131 deletions(-)
---
diff --git a/src/libtracker-data/tracker-data-update.c b/src/libtracker-data/tracker-data-update.c
index 53abf4b19..dd3ea6401 100644
--- a/src/libtracker-data/tracker-data-update.c
+++ b/src/libtracker-data/tracker-data-update.c
@@ -85,8 +85,8 @@ struct _TrackerDataUpdateBufferProperty {
        const gchar *name;
        GValue value;
        guint date_time : 1;
-
        guint fts : 1;
+       guint delete_all_values : 1;
 };
 
 struct _TrackerDataUpdateBufferTable {
@@ -611,6 +611,27 @@ cache_delete_row (TrackerData  *data,
        table->delete_row = TRUE;
 }
 
+/* Use only for multi-valued properties */
+static void
+cache_delete_all_values (TrackerData *data,
+                         const gchar *table_name,
+                         const gchar *field_name,
+                         gboolean     fts,
+                         gboolean     date_time)
+{
+       TrackerDataUpdateBufferTable    *table;
+       TrackerDataUpdateBufferProperty  property = { 0 };
+
+       property.name = field_name;
+       property.fts = fts;
+       property.date_time = date_time;
+       property.delete_all_values = TRUE;
+
+       table = cache_ensure_table (data, table_name, TRUE);
+       table->delete_value = TRUE;
+       g_array_append_val (table->properties, property);
+}
+
 static void
 cache_delete_value (TrackerData *data,
                     const gchar *table_name,
@@ -778,7 +799,12 @@ tracker_data_resource_buffer_flush (TrackerData                      *data,
                        for (i = 0; i < table->properties->len; i++) {
                                property = &g_array_index (table->properties, 
TrackerDataUpdateBufferProperty, i);
 
-                               if (table->delete_value) {
+                               if (table->delete_value && property->delete_all_values) {
+                                       stmt = tracker_db_interface_create_statement (iface, 
TRACKER_DB_STATEMENT_CACHE_TYPE_UPDATE, &actual_error,
+                                                                                     "DELETE FROM 
\"%s\".\"%s\" WHERE ID = ?",
+                                                                                     database,
+                                                                                     table_name);
+                               } else if (table->delete_value) {
                                        /* delete rows for multiple value properties */
                                        stmt = tracker_db_interface_create_statement (iface, 
TRACKER_DB_STATEMENT_CACHE_TYPE_UPDATE, &actual_error,
                                                                                      "DELETE FROM 
\"%s\".\"%s\" WHERE ID = ? AND \"%s\" = ?",
@@ -801,7 +827,9 @@ tracker_data_resource_buffer_flush (TrackerData                      *data,
                                param = 0;
 
                                tracker_db_statement_bind_int (stmt, param++, resource->id);
-                               statement_bind_gvalue (stmt, &param, &property->value);
+
+                               if (!property->delete_all_values)
+                                       statement_bind_gvalue (stmt, &param, &property->value);
 
                                tracker_db_statement_execute (stmt, &actual_error);
                                g_object_unref (stmt);
@@ -1637,76 +1665,6 @@ cache_insert_metadata_decomposed (TrackerData      *data,
        return change;
 }
 
-static gboolean
-delete_first_object (TrackerData      *data,
-                     TrackerProperty  *field,
-                     GArray           *old_values,
-                     GError          **error)
-{
-       gint pred_id = 0;
-       gint object_id = 0;
-       gboolean change = FALSE;
-
-       if (old_values->len == 0) {
-               return change;
-       }
-
-       pred_id = tracker_property_get_id (field);
-
-       if (tracker_property_get_data_type (field) == TRACKER_PROPERTY_TYPE_RESOURCE) {
-               GError *new_error = NULL;
-               GValue *v, copy = G_VALUE_INIT;
-
-               v = &g_array_index (old_values, GValue, 0);
-               g_value_init (&copy, G_VALUE_TYPE (v));
-               g_value_copy (v, &copy);
-
-               /* This influences old_values, which is a reference, not a copy */
-               change = delete_metadata_decomposed (data, field, &copy, &new_error);
-               g_value_unset (&copy);
-
-               if (new_error) {
-                       g_propagate_error (error, new_error);
-                       return change;
-               }
-       } else {
-               GValue *v, copy = G_VALUE_INIT;
-               GError *new_error = NULL;
-
-               object_id = 0;
-               v = &g_array_index (old_values, GValue, 0);
-               g_value_init (&copy, G_VALUE_TYPE (v));
-               g_value_copy (v, &copy);
-
-               /* This influences old_values, which is a reference, not a copy */
-               change = delete_metadata_decomposed (data, field, &copy, &new_error);
-               g_value_unset (&copy);
-
-               if (new_error) {
-                       g_propagate_error (error, new_error);
-                       return change;
-               }
-
-               if (data->delete_callbacks && change) {
-                       guint n;
-                       for (n = 0; n < data->delete_callbacks->len; n++) {
-                               TrackerStatementDelegate *delegate;
-
-                               delegate = g_ptr_array_index (data->delete_callbacks, n);
-                               delegate->callback (data->resource_buffer->graph->id,
-                                                   data->resource_buffer->graph->graph,
-                                                   data->resource_buffer->id,
-                                                   data->resource_buffer->subject,
-                                                   pred_id, object_id, NULL, /* FIXME */
-                                                   data->resource_buffer->types,
-                                                   delegate->user_data);
-                       }
-               }
-       }
-
-       return change;
-}
-
 static gboolean
 delete_metadata_decomposed (TrackerData      *data,
                             TrackerProperty  *property,
@@ -2130,62 +2088,6 @@ tracker_data_delete_statement (TrackerData  *data,
        }
 }
 
-static void
-delete_all_objects (TrackerData  *data,
-                    const gchar  *graph,
-                    const gchar  *subject,
-                    const gchar  *predicate,
-                    GError      **error)
-{
-       gint subject_id = 0;
-       gboolean change = FALSE;
-       GError *new_error = NULL;
-       TrackerProperty *field;
-       TrackerOntologies *ontologies;
-
-       g_return_if_fail (subject != NULL);
-       g_return_if_fail (predicate != NULL);
-       g_return_if_fail (data->in_transaction);
-
-       subject_id = query_resource_id (data, subject);
-
-       if (subject_id == 0) {
-               /* subject not in database */
-               return;
-       }
-
-       if (!resource_buffer_switch (data, graph, subject, subject_id, error))
-               return;
-
-       ontologies = tracker_data_manager_get_ontologies (data->manager);
-
-       field = tracker_ontologies_get_property_by_uri (ontologies, predicate);
-       if (field != NULL) {
-               GArray *old_values;
-
-               data->has_persistent = TRUE;
-               old_values = get_old_property_values (data, field, &new_error);
-               if (new_error) {
-                       g_propagate_error (error, new_error);
-                       return;
-               }
-
-               while (old_values->len > 0) {
-                       GError *new_error = NULL;
-
-                       change |= delete_first_object (data, field, old_values, &new_error);
-
-                       if (new_error) {
-                               g_propagate_error (error, new_error);
-                               return;
-                       }
-               }
-       } else {
-               g_set_error (error, TRACKER_SPARQL_ERROR, TRACKER_SPARQL_ERROR_UNKNOWN_PROPERTY,
-                            "Property '%s' not found in the ontology", predicate);
-       }
-}
-
 static gboolean
 delete_single_valued (TrackerData  *data,
                       const gchar  *graph,
@@ -2204,7 +2106,11 @@ delete_single_valued (TrackerData  *data,
        multiple_values = tracker_property_get_multiple_values (field);
 
        if (super_is_single_valued && multiple_values) {
-               delete_all_objects (data, graph, subject, predicate, error);
+               cache_delete_all_values (data,
+                                        tracker_property_get_table_name (field),
+                                        tracker_property_get_name (field),
+                                        tracker_property_get_fulltext_indexed (field),
+                                        tracker_property_get_data_type (field) == 
TRACKER_PROPERTY_TYPE_DATETIME);
        } else if (!multiple_values) {
                GError *inner_error = NULL;
                GArray *old_values;
@@ -2491,7 +2397,16 @@ tracker_data_update_statement (TrackerData  *data,
                                return;
                        }
 
-                       delete_all_objects (data, graph, subject, predicate, error);
+                       if (!resource_buffer_switch (data, graph, subject,
+                                                    ensure_resource_id (data, subject, NULL),
+                                                    error))
+                               return;
+
+                       cache_delete_all_values (data,
+                                                tracker_property_get_table_name (property),
+                                                tracker_property_get_name (property),
+                                                tracker_property_get_fulltext_indexed (property),
+                                                tracker_property_get_data_type (property) == 
TRACKER_PROPERTY_TYPE_DATETIME);
                } else {
                        if (!resource_buffer_switch (data, graph, subject,
                                                     ensure_resource_id (data, subject, NULL),