From 824e6d69bf4c337976e3cd3798857d2c6132fd30 Mon Sep 17 00:00:00 2001
From: Will Thompson <will@willthompson.co.uk>
Date: Thu, 30 Apr 2015 21:36:48 +0100
Subject: [PATCH 1/2] highlighter: remove redundant (?) call to $.show()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I don't understand why this would be necessary -- the element's just
been created, no style is (presumably) changing its display to anything
other than the default... -- and when highlighting all text in a 5000×3
table, $.show() accounts for 10s out of the 14s it takes to draw the
highlights.

$.show() being absurdly slow is a known problem:
https://github.com/jquery/jquery.com/issues/88
---
 src/ui/highlighter.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ui/highlighter.js b/src/ui/highlighter.js
index 0d10cca6e..e8fcfe837 100644
--- a/src/ui/highlighter.js
+++ b/src/ui/highlighter.js
@@ -34,7 +34,7 @@ function highlightRange(normedRange, cssClass) {
         var node = nodes[i];
         if (!white.test(node.nodeValue)) {
             results.push(
-                $(node).wrapAll(hl).parent().show()[0]
+                $(node).wrapAll(hl).parent()[0]
             );
         }
     }

From 2b2700eb251d6f96d18452e1d84dc8105fa949bc Mon Sep 17 00:00:00 2001
From: Will Thompson <will@willthompson.co.uk>
Date: Thu, 30 Apr 2015 22:07:11 +0100
Subject: [PATCH 2/2] Add span.annotator-hl wrappers without jQuery
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

This funtion accounted for ~1 second of the remaining time in my 5000×3
table test case. With this change it's more like 200ms, which is still
not ideal but a lot better.

$.wrapAll seems relatively expensive. I suppose it has to do lots of
extra work that's not necessary when we know we have exactly one element
to wrap at a time.
---
 src/ui/highlighter.js | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/ui/highlighter.js b/src/ui/highlighter.js
index e8fcfe837..b1e93dc5b 100644
--- a/src/ui/highlighter.js
+++ b/src/ui/highlighter.js
@@ -21,8 +21,6 @@ function highlightRange(normedRange, cssClass) {
     }
     var white = /^\s*$/;
 
-    var hl = $("<span class='" + cssClass + "'></span>");
-
     // Ignore text nodes that contain only whitespace characters. This prevents
     // spans being injected between elements that can only contain a restricted
     // subset of nodes such as table rows and lists. This does mean that there
@@ -33,9 +31,11 @@ function highlightRange(normedRange, cssClass) {
     for (var i = 0, len = nodes.length; i < len; i++) {
         var node = nodes[i];
         if (!white.test(node.nodeValue)) {
-            results.push(
-                $(node).wrapAll(hl).parent()[0]
-            );
+            var hl = document.createElement('span');
+            hl.className = cssClass;
+            node.parentNode.replaceChild(hl, node);
+            hl.appendChild(node);
+            results.push(hl);
         }
     }
     return results;