Bug#965275: atril: slow scrolling for large documents
Package: atril
Version: 1.20.3-1+deb10u1
Severity: normal
Tags: patch
This issue is fixed in evince but currently not in upstream atril, please see:
https://bugzilla.gnome.org/show_bug.cgi?id=779614
https://gitlab.gnome.org/GNOME/evince/-/commit/c3de8e75d6d0920478af210ba19a2d94b0734917
The attached patch can be applied to current stable (buster).
From c3de8e75d6d0920478af210ba19a2d94b0734917 Mon Sep 17 00:00:00 2001
From: Benjamin Berg <bberg@redhat.com>
Date: Wed, 26 Apr 2017 23:06:01 +0200
Subject: [PATCH] ev-sidebar-links: Optimize reverse link lookup for a page
For large documents the linear search for the first link that is on a
certain page is really slow. Because of this scrolling becomes slow
whenever the page changes.
Replace the linear search with a search in a binary tree populated with
the first link on each page and the corresponding GtkTreePath. This way
a specialized binary tree lookup can be used to find the closest
matching link and select that in the treeview.
https://bugzilla.gnome.org/show_bug.cgi?id=779614
---
shell/ev-sidebar-links.c | 142 ++++++++++++++++++++++-----------------
1 file changed, 82 insertions(+), 60 deletions(-)
diff --git a/shell/ev-sidebar-links.c b/shell/ev-sidebar-links.c
index 230a96a0..c16e649e 100644
--- a/shell/ev-sidebar-links.c
+++ b/shell/ev-sidebar-links.c
@@ -47,6 +47,8 @@ struct _EvSidebarLinksPrivate {
GtkTreeModel *model;
EvDocument *document;
EvDocumentModel *doc_model;
+
+ GTree *page_link_tree;
};
enum {
@@ -152,6 +154,11 @@ ev_sidebar_links_dispose (GObject *object)
sidebar->priv->model = NULL;
}
+ if (sidebar->priv->page_link_tree) {
+ g_tree_unref (sidebar->priv->page_link_tree);
+ sidebar->priv->page_link_tree = NULL;
+ }
+
if (sidebar->priv->document) {
g_object_unref (sidebar->priv->document);
sidebar->priv->document = NULL;
@@ -470,40 +477,20 @@ ev_sidebar_links_new (void)
return ev_sidebar_links;
}
-static gboolean
-update_page_callback_foreach (GtkTreeModel *model,
- GtkTreePath *path,
- GtkTreeIter *iter,
- gpointer data)
-{
- EvSidebarLinks *sidebar_links = (data);
- EvLink *link;
+typedef struct EvSidebarLinkPageSearch {
+ gint page;
+ gint best_existing;
+} EvSidebarLinkPageSearch;
- gtk_tree_model_get (model, iter,
- EV_DOCUMENT_LINKS_COLUMN_LINK, &link,
- -1);
-
- if (link) {
- int current_page;
- int dest_page;
- EvDocumentLinks *document_links = EV_DOCUMENT_LINKS (sidebar_links->priv->document);
+static gint
+page_link_tree_search_best_page (gpointer page_ptr, EvSidebarLinkPageSearch* data)
+{
+ gint page = GPOINTER_TO_INT (page_ptr);
- dest_page = ev_document_links_get_link_page (document_links, link);
- g_object_unref (link);
-
- current_page = ev_document_model_get_page (sidebar_links->priv->doc_model);
-
- if (dest_page == current_page) {
- gtk_tree_view_expand_to_path (GTK_TREE_VIEW (sidebar_links->priv->tree_view),
- path);
- gtk_tree_view_set_cursor (GTK_TREE_VIEW (sidebar_links->priv->tree_view),
- path, NULL, FALSE);
-
- return TRUE;
- }
- }
+ if (page <= data->page && page > data->best_existing)
+ data->best_existing = page;
- return FALSE;
+ return data->page - page;
}
static void
@@ -511,45 +498,35 @@ ev_sidebar_links_set_current_page (EvSidebarLinks *sidebar_links,
gint current_page)
{
GtkTreeSelection *selection;
- GtkTreeModel *model;
- GtkTreeIter iter;
+ GtkTreePath *path;
+ EvSidebarLinkPageSearch search_data;
/* Widget is not currently visible */
- if (!gtk_widget_get_mapped (GTK_WIDGET (sidebar_links)))
+ if (!gtk_widget_is_visible (GTK_WIDGET (sidebar_links)))
return;
-
- selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (sidebar_links->priv->tree_view));
- if (gtk_tree_selection_get_selected (selection, &model, &iter)) {
- EvLink *link;
+ search_data.page = current_page;
+ search_data.best_existing = G_MININT;
- gtk_tree_model_get (model, &iter,
- EV_DOCUMENT_LINKS_COLUMN_LINK, &link,
- -1);
- if (link) {
- gint dest_page;
- EvDocumentLinks *document_links = EV_DOCUMENT_LINKS (sidebar_links->priv->document);
+ path = g_tree_search (sidebar_links->priv->page_link_tree, (GCompareFunc) page_link_tree_search_best_page, &search_data);
+ /* No direct hit, try a lookup on the best match. */
+ if (!path)
+ path = g_tree_lookup (sidebar_links->priv->page_link_tree, GINT_TO_POINTER (search_data.best_existing));
- dest_page = ev_document_links_get_link_page (document_links, link);
- g_object_unref (link);
-
- if (dest_page == current_page)
- return;
- }
- }
+ /* Still no hit, give up. */
+ if (!path)
+ return;
+
+ selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (sidebar_links->priv->tree_view));
- /* We go through the tree linearly looking for the first page that
- * matches. This is pretty inefficient. We can do something neat with
- * a GtkTreeModelSort here to make it faster, if it turns out to be
- * slow.
- */
g_signal_handler_block (selection, sidebar_links->priv->selection_id);
g_signal_handler_block (sidebar_links->priv->tree_view, sidebar_links->priv->row_activated_id);
- gtk_tree_model_foreach (model,
- update_page_callback_foreach,
- sidebar_links);
-
+ gtk_tree_view_expand_to_path (GTK_TREE_VIEW (sidebar_links->priv->tree_view),
+ path);
+ gtk_tree_view_set_cursor (GTK_TREE_VIEW (sidebar_links->priv->tree_view),
+ path, NULL, FALSE);
+
g_signal_handler_unblock (selection, sidebar_links->priv->selection_id);
g_signal_handler_unblock (sidebar_links->priv->tree_view, sidebar_links->priv->row_activated_id);
}
@@ -599,6 +576,42 @@ expand_open_links (GtkTreeView *tree_view, GtkTreeModel *model, GtkTreeIter *par
}
}
+
+static gint
+page_link_tree_sort (gconstpointer a, gconstpointer b, void *data)
+{
+ return GPOINTER_TO_INT (a) - GPOINTER_TO_INT (b);
+}
+
+static gboolean
+update_page_link_tree_foreach (GtkTreeModel *model,
+ GtkTreePath *path,
+ GtkTreeIter *iter,
+ gpointer data)
+{
+ EvSidebarLinks *sidebar_links = data;
+ EvSidebarLinksPrivate *priv = sidebar_links->priv;
+ EvDocumentLinks *document_links = EV_DOCUMENT_LINKS (priv->document);
+ EvLink *link;
+ int page;
+
+ gtk_tree_model_get (model, iter,
+ EV_DOCUMENT_LINKS_COLUMN_LINK, &link,
+ -1);
+
+ if (!link)
+ return FALSE;
+
+ page = ev_document_links_get_link_page (document_links, link);
+ g_object_unref (link);
+
+ /* Only save the first link we find per page. */
+ if (!g_tree_lookup (priv->page_link_tree, GINT_TO_POINTER (page)))
+ g_tree_insert (priv->page_link_tree, GINT_TO_POINTER (page), gtk_tree_path_copy (path));
+
+ return FALSE;
+}
+
static void
ev_sidebar_links_set_links_model (EvSidebarLinks *sidebar_links,
GtkTreeModel *model)
@@ -612,6 +625,15 @@ ev_sidebar_links_set_links_model (EvSidebarLinks *sidebar_links,
g_object_unref (priv->model);
priv->model = g_object_ref (model);
+ /* Rebuild the binary search tree for finding links on pages. */
+ if (priv->page_link_tree)
+ g_tree_unref (priv->page_link_tree);
+ priv->page_link_tree = g_tree_new_full (page_link_tree_sort, NULL, NULL, (GDestroyNotify) gtk_tree_path_free);
+
+ gtk_tree_model_foreach (model,
+ update_page_link_tree_foreach,
+ sidebar_links);
+
g_object_notify (G_OBJECT (sidebar_links), "model");
}
--
2.20.1
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