From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Mon, 7 Nov 2022 05:38:43 +0000 (-0500)
Subject: (itree_insert_gap, itree_delete_gap): Minor optimization
X-Git-Tag: emacs-29.0.90~1616^2~252
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=35221a7bd55e18244604376497097f4259c7351b;p=emacs.git

(itree_insert_gap, itree_delete_gap): Minor optimization

`limit` can get smaller in either of the two children of a node.
It can also happen that the root node itself has a low enough limit
that the loop can be interrupted right away.

The previous code only checked `limit` when going down to a left
child, which is not wrong, but tests suggest that it is also very
common to reach this limit when going to a right child, so move the
test accordingly.

* src/itree.c (itree_insert_gap, itree_delete_gap): Check `limit` for
all nodes, rather than only when following a `left` pointer.
---

diff --git a/src/itree.c b/src/itree.c
index d73fbffd2b6..989173db4e5 100644
--- a/src/itree.c
+++ b/src/itree.c
@@ -1240,6 +1240,8 @@ itree_insert_gap (struct itree_tree *tree,
 	{
 	  /* Process in pre-order. */
 	  interval_tree_inherit_offset (tree->otick, node);
+	  if (pos > node->limit)
+	    continue;
 	  if (node->right != NULL)
 	    {
 	      if (node->begin > pos)
@@ -1251,8 +1253,7 @@ itree_insert_gap (struct itree_tree *tree,
 	      else
 		interval_stack_push (stack, node->right);
 	    }
-	  if (node->left != NULL
-	      && pos <= node->left->limit + node->left->offset)
+	  if (node->left != NULL)
 	    interval_stack_push (stack, node->left);
 
 	  if (before_markers
@@ -1312,6 +1313,8 @@ itree_delete_gap (struct itree_tree *tree,
     {
       node = nav_nodeptr (nav);
       interval_tree_inherit_offset (tree->otick, node);
+      if (pos > node->limit)
+	continue;
       if (node->right != NULL)
 	{
 	  if (node->begin > pos + length)
@@ -1323,8 +1326,7 @@ itree_delete_gap (struct itree_tree *tree,
 	  else
 	    interval_stack_push (stack, node->right);
 	}
-      if (node->left != NULL
-	  && pos <= node->left->limit + node->left->offset)
+      if (node->left != NULL)
 	interval_stack_push (stack, node->left);
 
       if (pos < node->begin)