<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[173184] trunk</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/173184">173184</a></dd>
<dt>Author</dt> <dd>simon.fraser@apple.com</dd>
<dt>Date</dt> <dd>2014-09-02 13:20:25 -0700 (Tue, 02 Sep 2014)</dd>
</dl>
<h3>Log Message</h3>
<pre>Avoid backing store allocation with some combinations of replaced elements, masking and visibility:hidden
https://bugs.webkit.org/show_bug.cgi?id=136400
Reviewed by Tim Horton.
Source/WebCore:
RenderLayer::isVisuallyNonEmpty() would return true for replaced elements (e.g. images)
with visibility:hidden, and for layers with a mask, and both would cause additional
backing store in some cases.
We can move the hasVisibleContent() to the top of the function, since visibility:hidden
will always hide any content of this layer. The hasMask() check can also be removed;
a mask can only mask content that is already visible; it never contributes additional
pixels.
Tests: compositing/backing/masked-child-no-backing.html
compositing/backing/replaced-child-no-backing.html
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::calculateClipRects):
LayoutTests:
* compositing/backing/masked-child-no-backing-expected.txt: Added.
* compositing/backing/masked-child-no-backing.html: Added.
* compositing/backing/replaced-child-no-backing-expected.txt: Added.
* compositing/backing/replaced-child-no-backing.html: Added.</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkLayoutTestsChangeLog">trunk/LayoutTests/ChangeLog</a></li>
<li><a href="#trunkSourceWebCoreChangeLog">trunk/Source/WebCore/ChangeLog</a></li>
<li><a href="#trunkSourceWebCorerenderingRenderLayercpp">trunk/Source/WebCore/rendering/RenderLayer.cpp</a></li>
</ul>
<h3>Added Paths</h3>
<ul>
<li><a href="#trunkLayoutTestscompositingbackingmaskedchildnobackingexpectedtxt">trunk/LayoutTests/compositing/backing/masked-child-no-backing-expected.txt</a></li>
<li><a href="#trunkLayoutTestscompositingbackingmaskedchildnobackinghtml">trunk/LayoutTests/compositing/backing/masked-child-no-backing.html</a></li>
<li><a href="#trunkLayoutTestscompositingbackingreplacedchildnobackingexpectedtxt">trunk/LayoutTests/compositing/backing/replaced-child-no-backing-expected.txt</a></li>
<li><a href="#trunkLayoutTestscompositingbackingreplacedchildnobackinghtml">trunk/LayoutTests/compositing/backing/replaced-child-no-backing.html</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkLayoutTestsChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/LayoutTests/ChangeLog (173183 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/ChangeLog        2014-09-02 20:14:31 UTC (rev 173183)
+++ trunk/LayoutTests/ChangeLog        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -1,5 +1,17 @@
</span><span class="cx"> 2014-09-02 Simon Fraser <simon.fraser@apple.com>
</span><span class="cx">
</span><ins>+ Avoid backing store allocation with some combinations of replaced elements, masking and visibility:hidden
+ https://bugs.webkit.org/show_bug.cgi?id=136400
+
+ Reviewed by Tim Horton.
+
+ * compositing/backing/masked-child-no-backing-expected.txt: Added.
+ * compositing/backing/masked-child-no-backing.html: Added.
+ * compositing/backing/replaced-child-no-backing-expected.txt: Added.
+ * compositing/backing/replaced-child-no-backing.html: Added.
+
+2014-09-02 Simon Fraser <simon.fraser@apple.com>
+
</ins><span class="cx"> Non-composited child RenderLayers cause allocation of unncessary backing store
</span><span class="cx"> https://bugs.webkit.org/show_bug.cgi?id=136375
</span><span class="cx">
</span></span></pre></div>
<a id="trunkLayoutTestscompositingbackingmaskedchildnobackingexpectedtxt"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/compositing/backing/masked-child-no-backing-expected.txt (0 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/compositing/backing/masked-child-no-backing-expected.txt         (rev 0)
+++ trunk/LayoutTests/compositing/backing/masked-child-no-backing-expected.txt        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -0,0 +1,22 @@
</span><ins>+(GraphicsLayer
+ (anchor 0.00 0.00)
+ (bounds 800.00 600.00)
+ (children 1
+ (GraphicsLayer
+ (bounds 800.00 600.00)
+ (contentsOpaque 1)
+ (children 2
+ (GraphicsLayer
+ (position 18.00 10.00)
+ (bounds 200.00 200.00)
+ )
+ (GraphicsLayer
+ (position 18.00 220.00)
+ (bounds 200.00 200.00)
+ (drawsContent 1)
+ )
+ )
+ )
+ )
+)
+
</ins></span></pre></div>
<a id="trunkLayoutTestscompositingbackingmaskedchildnobackinghtml"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/compositing/backing/masked-child-no-backing.html (0 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/compositing/backing/masked-child-no-backing.html         (rev 0)
+++ trunk/LayoutTests/compositing/backing/masked-child-no-backing.html        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -0,0 +1,57 @@
</span><ins>+<!DOCTYPE html>
+
+<html>
+<head>
+ <style>
+ .container {
+ position: relative;
+ height: 200px;
+ width: 200px;
+ margin: 10px;
+ }
+
+ .composited {
+ -webkit-transform: translateZ(0);
+ }
+
+ .child {
+ position: absolute;
+ height: 180px;
+ width: 180px;
+ margin: 10px;
+ }
+
+ .masked {
+ -webkit-mask: linear-gradient(black, transparent);
+ }
+
+ .grandchild {
+ position: absolute;
+ top: 10px;
+ left: 10px;
+ width: 150px;
+ height: 150px;
+ background-color: silver;
+ }
+ </style>
+ <script>
+ if (window.testRunner)
+ testRunner.dumpAsText();
+
+ function dumpLayers()
+ {
+ var layersResult = document.getElementById('layers');
+ if (window.testRunner)
+ layersResult.innerText = window.internals.layerTreeAsText(document);
+ }
+
+ window.addEventListener('load', dumpLayers, false)
+ </script>
+</head>
+<body>
+ <div class="composited container"><div class="masked child"></div></div>
+ <div class="composited container"><div class="masked child"><div class="grandchild"></div></div></div>
+
+<pre id="layers">Layer tree goes here in DRT</pre>
+</body>
+</html>
</ins></span></pre></div>
<a id="trunkLayoutTestscompositingbackingreplacedchildnobackingexpectedtxt"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/compositing/backing/replaced-child-no-backing-expected.txt (0 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/compositing/backing/replaced-child-no-backing-expected.txt         (rev 0)
+++ trunk/LayoutTests/compositing/backing/replaced-child-no-backing-expected.txt        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -0,0 +1,25 @@
</span><ins>+
+(GraphicsLayer
+ (anchor 0.00 0.00)
+ (bounds 800.00 600.00)
+ (children 1
+ (GraphicsLayer
+ (bounds 800.00 600.00)
+ (contentsOpaque 1)
+ (children 2
+ (GraphicsLayer
+ (position 18.00 10.00)
+ (anchor 0.50 0.49)
+ (bounds 200.00 204.00)
+ (drawsContent 1)
+ )
+ (GraphicsLayer
+ (position 18.00 220.00)
+ (anchor 0.50 0.49)
+ (bounds 200.00 204.00)
+ )
+ )
+ )
+ )
+)
+
</ins></span></pre></div>
<a id="trunkLayoutTestscompositingbackingreplacedchildnobackinghtml"></a>
<div class="addfile"><h4>Added: trunk/LayoutTests/compositing/backing/replaced-child-no-backing.html (0 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/LayoutTests/compositing/backing/replaced-child-no-backing.html         (rev 0)
+++ trunk/LayoutTests/compositing/backing/replaced-child-no-backing.html        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -0,0 +1,51 @@
</span><ins>+<!DOCTYPE html>
+
+<html>
+<head>
+ <style>
+ .container {
+ height: 200px;
+ width: 200px;
+ margin: 10px;
+ }
+
+ .composited {
+ -webkit-transform: translateZ(0);
+ }
+
+ .child {
+ position: relative;
+ height: 100%;
+ width: 100%;
+ }
+
+ .grandchild {
+ position: absolute;
+ top: 10px;
+ left: 10px;
+ width: 150px;
+ height: 150px;
+ background-color: silver;
+ }
+ </style>
+ <script>
+ if (window.testRunner)
+ testRunner.dumpAsText();
+
+ function dumpLayers()
+ {
+ var layersResult = document.getElementById('layers');
+ if (window.testRunner)
+ layersResult.innerText = window.internals.layerTreeAsText(document);
+ }
+
+ window.addEventListener('load', dumpLayers, false)
+ </script>
+</head>
+<body>
+ <div class="composited container"><img class="child" src="../resources/apple.jpg"></div>
+ <div class="composited container"><img class="child" src="../resources/apple.jpg" style="visibility:hidden"></div>
+
+<pre id="layers">Layer tree goes here in DRT</pre>
+</body>
+</html>
</ins></span></pre></div>
<a id="trunkSourceWebCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/ChangeLog (173183 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/ChangeLog        2014-09-02 20:14:31 UTC (rev 173183)
+++ trunk/Source/WebCore/ChangeLog        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -1,3 +1,25 @@
</span><ins>+2014-09-02 Simon Fraser <simon.fraser@apple.com>
+
+ Avoid backing store allocation with some combinations of replaced elements, masking and visibility:hidden
+ https://bugs.webkit.org/show_bug.cgi?id=136400
+
+ Reviewed by Tim Horton.
+
+ RenderLayer::isVisuallyNonEmpty() would return true for replaced elements (e.g. images)
+ with visibility:hidden, and for layers with a mask, and both would cause additional
+ backing store in some cases.
+
+ We can move the hasVisibleContent() to the top of the function, since visibility:hidden
+ will always hide any content of this layer. The hasMask() check can also be removed;
+ a mask can only mask content that is already visible; it never contributes additional
+ pixels.
+
+ Tests: compositing/backing/masked-child-no-backing.html
+ compositing/backing/replaced-child-no-backing.html
+
+ * rendering/RenderLayer.cpp:
+ (WebCore::RenderLayer::calculateClipRects):
+
</ins><span class="cx"> 2014-09-02 Joseph Pecoraro <pecoraro@apple.com>
</span><span class="cx">
</span><span class="cx"> Use jsNontrivialString for strings we know are more than a single character
</span></span></pre></div>
<a id="trunkSourceWebCorerenderingRenderLayercpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/WebCore/rendering/RenderLayer.cpp (173183 => 173184)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/WebCore/rendering/RenderLayer.cpp        2014-09-02 20:14:31 UTC (rev 173183)
+++ trunk/Source/WebCore/rendering/RenderLayer.cpp        2014-09-02 20:20:25 UTC (rev 173184)
</span><span class="lines">@@ -6316,11 +6316,13 @@
</span><span class="cx"> {
</span><span class="cx"> ASSERT(!m_visibleDescendantStatusDirty);
</span><span class="cx">
</span><del>- if (hasVisibleContent() && hasNonEmptyChildRenderers())
</del><ins>+ if (!hasVisibleContent())
+ return false;
+
+ if (hasNonEmptyChildRenderers())
</ins><span class="cx"> return true;
</span><span class="cx">
</span><del>- // FIXME: a visibility:hidden replaced element should return false here.
- if (renderer().isReplaced() || renderer().hasMask())
</del><ins>+ if (renderer().isReplaced())
</ins><span class="cx"> return true;
</span><span class="cx">
</span><span class="cx"> if (hasVisibleBoxDecorations())
</span></span></pre>
</div>
</div>
</body>
</html>