[tracker/wip/carlosg/fixes: 1/8] libtracker-sparql: Refactor code writing cursor to a fd

[Carlos Garnacho <carlosg src gnome org>]

commit 611cb952372c48763b13210277cb7aa01c0a9dbe
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Mar 1 14:09:32 2020 +0100

    libtracker-sparql: Refactor code writing cursor to a fd
    
    Just move it to a separate function, as we'll be using it in more
    than one place.

 src/libtracker-sparql/tracker-endpoint-dbus.c | 69 +++++++++++++++++++--------
 1 file changed, 48 insertions(+), 21 deletions(-)
---
diff --git a/src/libtracker-sparql/tracker-endpoint-dbus.c b/src/libtracker-sparql/tracker-endpoint-dbus.c
index c9ef380b0..89e12fa98 100644
--- a/src/libtracker-sparql/tracker-endpoint-dbus.c
+++ b/src/libtracker-sparql/tracker-endpoint-dbus.c
@@ -206,33 +206,21 @@ update_request_free (UpdateRequest *request)
        g_free (request);
 }
 
-static void
-query_cb (GObject      *object,
-          GAsyncResult *res,
-          gpointer      user_data)
+static gboolean
+write_cursor (QueryRequest          *request,
+              TrackerSparqlCursor   *cursor,
+              GError               **error)
 {
-       QueryRequest *request = user_data;
-       TrackerSparqlCursor *cursor;
-       GError *error = NULL;
        const gchar **values = NULL;
-       const gchar **variable_names = NULL;
        glong *offsets = NULL;
        gint i, n_columns = 0;
-
-       cursor = tracker_sparql_connection_query_finish (TRACKER_SPARQL_CONNECTION (object),
-                                                        res, &error);
-       if (!cursor)
-               goto error;
+       GError *inner_error = NULL;
 
        n_columns = tracker_sparql_cursor_get_n_columns (cursor);
-       variable_names = g_new0 (const gchar *, n_columns + 1);
        values = g_new0 (const char *, n_columns);
        offsets = g_new0 (glong, n_columns);
 
-       for (i = 0; i < n_columns; i++)
-               variable_names[i] = tracker_sparql_cursor_get_variable_name (cursor, i);
-
-       while (tracker_sparql_cursor_next (cursor, NULL, &error)) {
+       while (tracker_sparql_cursor_next (cursor, NULL, &inner_error)) {
                glong cur_offset = -1;
 
                g_data_output_stream_put_int32 (request->data_stream, n_columns, NULL, NULL);
@@ -262,17 +250,56 @@ query_cb (GObject      *object,
                }
        }
 
-error:
+       g_free (values);
+       g_free (offsets);
+
+       if (inner_error) {
+               g_propagate_error (error, inner_error);
+               return FALSE;
+       } else {
+               return TRUE;
+       }
+}
+
+/* Takes ownership on both cursor and error */
+static void
+handle_cursor_reply (QueryRequest        *request,
+                     TrackerSparqlCursor *cursor,
+                     GError              *error)
+{
+       const gchar **variable_names = NULL;
+       gint i, n_columns;
+
+       if (!error) {
+               n_columns = tracker_sparql_cursor_get_n_columns (cursor);
+               variable_names = g_new0 (const gchar *, n_columns + 1);
+               for (i = 0; i < n_columns; i++)
+                       variable_names[i] = tracker_sparql_cursor_get_variable_name (cursor, i);
+
+               write_cursor (request, cursor, &error);
+       }
+
        if (error)
                g_dbus_method_invocation_return_gerror (request->invocation, error);
        else
                g_dbus_method_invocation_return_value (request->invocation, g_variant_new ("(^as)", 
variable_names));
 
        g_free (variable_names);
-       g_free (values);
-       g_free (offsets);
        g_clear_object (&cursor);
+}
 
+static void
+query_cb (GObject      *object,
+          GAsyncResult *res,
+          gpointer      user_data)
+{
+       QueryRequest *request = user_data;
+       TrackerSparqlCursor *cursor;
+       GError *error = NULL;
+
+       cursor = tracker_sparql_connection_query_finish (TRACKER_SPARQL_CONNECTION (object),
+                                                        res, &error);
+       handle_cursor_reply (request, cursor, error);
        query_request_free (request);
 }