[gtksourceview/wip/search: 23/36] search: speed up the search (almost 2x faster)

[Sébastien Wilmet <swilmet src gnome org>]

commit 9f3c9a21bdf4fe0f0ed5ae690e4d152010e3c4d5
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Tue Jul 2 19:38:48 2013 +0200

    search: speed up the search (almost 2x faster)
    
    It was a known performance issue, not difficult to fix.

 gtksourceview/gtksourcesearch.c |   70 ++++++++++++++++++++++++++++++++-------
 1 files changed, 58 insertions(+), 12 deletions(-)
---
diff --git a/gtksourceview/gtksourcesearch.c b/gtksourceview/gtksourcesearch.c
index 7160f97..4242e5b 100644
--- a/gtksourceview/gtksourcesearch.c
+++ b/gtksourceview/gtksourcesearch.c
@@ -829,6 +829,58 @@ adjust_subregion (GtkSourceSearch *search,
        });
 }
 
+/* Do not take into account the scan_region. Search just with
+ * forward_to_tag_toggle(), and checks that it is not an old match.
+ */
+static gboolean
+smart_forward_search_without_scanning (GtkSourceSearch   *search,
+                                      const GtkTextIter *start_at,
+                                      GtkTextIter       *match_start,
+                                      GtkTextIter       *match_end,
+                                      const GtkTextIter *stop_at)
+{
+       GtkTextIter iter = *start_at;
+       GtkTextIter limit;
+
+       g_assert (start_at != NULL);
+       g_assert (stop_at != NULL);
+
+       if (gtk_text_iter_compare (stop_at, start_at) <= 0 ||
+           search->priv->text == NULL)
+       {
+               return FALSE;
+       }
+
+       if (search->priv->found_tag == NULL)
+       {
+               init_found_tag (search);
+       }
+
+       if (!gtk_text_iter_has_tag (&iter, search->priv->found_tag))
+       {
+               gtk_text_iter_forward_to_tag_toggle (&iter, search->priv->found_tag);
+       }
+
+       limit = iter;
+       gtk_text_iter_forward_to_tag_toggle (&limit, search->priv->found_tag);
+
+       if (gtk_text_iter_compare (stop_at, &limit) < 0)
+       {
+               limit = *stop_at;
+       }
+
+       if (basic_forward_search (search, &iter, match_start, match_end, &limit))
+       {
+               return TRUE;
+       }
+
+       return smart_forward_search_without_scanning (search,
+                                                     &limit,
+                                                     match_start,
+                                                     match_end,
+                                                     stop_at);
+}
+
 /* Remove the occurrences in the range. @start and @end may be adjusted, if they
  * are in a found_tag region.
  */
@@ -858,20 +910,9 @@ remove_occurrences_in_range (GtkSourceSearch *search,
                gtk_text_iter_forward_to_tag_toggle (end, search->priv->found_tag);
        }
 
-       gtk_text_buffer_remove_tag (search->priv->buffer,
-                                   search->priv->found_tag,
-                                   start,
-                                   end);
-
-       if (search->priv->text == NULL)
-       {
-               return;
-       }
-
        iter = *start;
 
-       /* TODO optimization: search with forward_to_tag_toggle() */
-       while (basic_forward_search (search, &iter, &match_start, &match_end, end))
+       while (smart_forward_search_without_scanning (search, &iter, &match_start, &match_end, end))
        {
                if (search->priv->scan_region == NULL)
                {
@@ -898,6 +939,11 @@ remove_occurrences_in_range (GtkSourceSearch *search,
 
                iter = match_end;
        }
+
+       gtk_text_buffer_remove_tag (search->priv->buffer,
+                                   search->priv->found_tag,
+                                   start,
+                                   end);
 }
 
 static void