file-undo-operations: use queue for storing sources and destinations

When copying, moving or linking files, original sources and their destinations
are stored in an information structure used for undoing the operation. The
sources and destinations were appended at the end of a list. Due to append
taking linear time, these file operations would have a resulting quadratic
complexity depending on the number of files. When operating on thousands of
files, this would lead to a significant decrease in speed. In order to fix
this, the sources and destinations are stored in a queue that allows appending
in constant time.

https://bugzilla.gnome.org/show_bug.cgi?id=757747

1 files changed, 43 insertions, 26 deletions

diff --git a/libnautilus-private/nautilus-file-undo-operations.c b/libnautilus-private/nautilus-file-undo-operations.c
index 9e96b35ed..01f27f343 100644
--- a/libnautilus-private/nautilus-file-undo-operations.c
+++ b/libnautilus-private/nautilus-file-undo-operations.c
@@ -322,8 +322,8 @@ G_DEFINE_TYPE (NautilusFileUndoInfoExt, nautilus_file_undo_info_ext, NAUTILUS_TY
 struct _NautilusFileUndoInfoExtDetails {
 	GFile *src_dir;
 	GFile *dest_dir;
-	GList *sources;	     /* Relative to src_dir */
-	GList *destinations; /* Relative to dest_dir */
+        GQueue *sources;      /* Relative to src_dir */
+        GQueue *destinations; /* Relative to dest_dir */
 };
 
 static char *
@@ -332,7 +332,7 @@ ext_get_first_target_short_name (NautilusFileUndoInfoExt *self)
 	GList *targets_first;
 	char *file_name = NULL;
 
-	targets_first = g_list_first (self->priv->destinations);
+        targets_first = g_queue_peek_head_link (self->priv->destinations);
 
 	if (targets_first != NULL &&
 	    targets_first->data != NULL) {
@@ -471,35 +471,47 @@ static void
 ext_create_link_redo_func (NautilusFileUndoInfoExt *self,
 			   GtkWindow *parent_window)
 {
-	nautilus_file_operations_link (self->priv->sources, NULL,
-				       self->priv->dest_dir, parent_window,
-				       file_undo_info_transfer_callback, self);
+        nautilus_file_operations_link (g_queue_peek_head_link (self->priv->sources),
+                                       NULL,
+                                       self->priv->dest_dir,
+                                       parent_window,
+                                       file_undo_info_transfer_callback,
+                                       self);
 }
 
 static void
 ext_duplicate_redo_func (NautilusFileUndoInfoExt *self,
 			 GtkWindow *parent_window)
 {
-	nautilus_file_operations_duplicate (self->priv->sources, NULL, parent_window,
-					    file_undo_info_transfer_callback, self);
+        nautilus_file_operations_duplicate (g_queue_peek_head_link (self->priv->sources),
+                                            NULL,
+                                            parent_window,
+                                            file_undo_info_transfer_callback,
+                                            self);
 }
 
 static void
 ext_copy_redo_func (NautilusFileUndoInfoExt *self,
 		    GtkWindow *parent_window)
 {
-	nautilus_file_operations_copy (self->priv->sources, NULL,
-				       self->priv->dest_dir, parent_window,
-				       file_undo_info_transfer_callback, self);
+        nautilus_file_operations_copy (g_queue_peek_head_link (self->priv->sources),
+                                       NULL,
+                                       self->priv->dest_dir,
+                                       parent_window,
+                                       file_undo_info_transfer_callback,
+                                       self);
 }
 
 static void
 ext_move_restore_redo_func (NautilusFileUndoInfoExt *self,
 			    GtkWindow *parent_window)
 {
-	nautilus_file_operations_move (self->priv->sources, NULL,
-				       self->priv->dest_dir, parent_window,
-				       file_undo_info_transfer_callback, self);
+        nautilus_file_operations_move (g_queue_peek_head_link (self->priv->sources),
+                                       NULL,
+                                       self->priv->dest_dir,
+                                       parent_window,
+                                       file_undo_info_transfer_callback,
+                                       self);
 }
 
 static void
@@ -527,8 +539,10 @@ static void
 ext_restore_undo_func (NautilusFileUndoInfoExt *self,
 		       GtkWindow *parent_window)
 {
-	nautilus_file_operations_trash_or_delete (self->priv->destinations, parent_window,
-						  file_undo_info_delete_callback, self);
+        nautilus_file_operations_trash_or_delete (g_queue_peek_head_link (self->priv->destinations),
+                                                  parent_window,
+                                                  file_undo_info_delete_callback,
+                                                  self);
 }
 
 
@@ -536,9 +550,12 @@ static void
 ext_move_undo_func (NautilusFileUndoInfoExt *self,
 		    GtkWindow *parent_window)
 {
-	nautilus_file_operations_move (self->priv->destinations, NULL,
-				       self->priv->src_dir, parent_window,
-				       file_undo_info_transfer_callback, self);
+        nautilus_file_operations_move (g_queue_peek_head_link (self->priv->destinations),
+                                       NULL,
+                                       self->priv->src_dir,
+                                       parent_window,
+                                       file_undo_info_transfer_callback,
+                                       self);
 }
 
 static void
@@ -547,7 +564,7 @@ ext_copy_duplicate_undo_func (NautilusFileUndoInfoExt *self,
 {
 	GList *files;
 
-	files = g_list_copy (self->priv->destinations);
+        files = g_list_copy (g_queue_peek_head_link (self->priv->destinations));
 	files = g_list_reverse (files); /* Deleting must be done in reverse */
 
 	nautilus_file_operations_delete (files, parent_window,
@@ -589,11 +606,11 @@ nautilus_file_undo_info_ext_finalize (GObject *obj)
 	NautilusFileUndoInfoExt *self = NAUTILUS_FILE_UNDO_INFO_EXT (obj);
 
 	if (self->priv->sources) {
-		g_list_free_full (self->priv->sources, g_object_unref);
+                g_queue_free_full (self->priv->sources, g_object_unref);
 	}
 
 	if (self->priv->destinations) {
-		g_list_free_full (self->priv->destinations, g_object_unref);
+                g_queue_free_full (self->priv->destinations, g_object_unref);
 	}
 
 	g_clear_object (&self->priv->src_dir);
@@ -632,6 +649,8 @@ nautilus_file_undo_info_ext_new (NautilusFileUndoOp op_type,
 
 	retval->priv->src_dir = g_object_ref (src_dir);
 	retval->priv->dest_dir = g_object_ref (target_dir);
+        retval->priv->sources = g_queue_new ();
+        retval->priv->destinations = g_queue_new ();
 
 	return NAUTILUS_FILE_UNDO_INFO (retval);
 }
@@ -641,10 +660,8 @@ nautilus_file_undo_info_ext_add_origin_target_pair (NautilusFileUndoInfoExt *sel
 						    GFile                   *origin,
 						    GFile                   *target)
 {
-	self->priv->sources =
-		g_list_append (self->priv->sources, g_object_ref (origin));
-	self->priv->destinations =
-		g_list_append (self->priv->destinations, g_object_ref (target));
+        g_queue_push_tail (self->priv->sources, g_object_ref (origin));
+        g_queue_push_tail (self->priv->destinations, g_object_ref (target));
 }
 
 /* create new file/folder */