Avoiding multiple text/string parsing while creating TextRun

Source/core/rendering/RenderText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 38 matching lines @@
 using namespace WTF;
 using namespace Unicode;
 
 namespace WebCore {
 
 struct SameSizeAsRenderText : public RenderObject {
     uint32_t bitfields : 16;
     float widths[4];
     String text;
     void* pointers[2];
+    CodePath someCodePath;

[eseidel, 2013/12/27 04:36:45]

nit: I would have called this "codePath".

 };
 
 COMPILE_ASSERT(sizeof(RenderText) == sizeof(SameSizeAsRenderText), RenderText_should_stay_small);
 
 class SecureTextTimer;
 typedef HashMap<RenderText*, SecureTextTimer*> SecureTextTimerMap;
 static SecureTextTimerMap* gSecureTextTimers = 0;
 
 class SecureTextTimer : public TimerBase {
 public:
@@ skipping 691 matching lines @@
         return w;
     }
 
     TextRun run = RenderBlockFlow::constructTextRun(const_cast<RenderText*>(this), f, this, start, len, style());
     run.setCharactersLength(textLength() - start);
     ASSERT(run.charactersLength() >= run.length());
 
     run.setCharacterScanForCodePath(!canUseSimpleFontCodePath());
     run.setTabSize(!style()->collapseWhiteSpace(), style()->tabSize());
     run.setXPos(xPos);
+
     return f.width(run, fallbackFonts, glyphOverflow);
 }
 
 void RenderText::trimmedPrefWidths(float leadWidth,
     float& firstLineMinWidth, bool& hasBreakableStart,
     float& lastLineMinWidth, bool& hasBreakableEnd,
     bool& hasBreakableChar, bool& hasBreak,
     float& firstLineMaxWidth, float& lastLineMaxWidth,
     float& minWidth, float& maxWidth, bool& stripFrontSpaces)
 {
@@ skipping 1018 matching lines @@
     if (!iterator)
         return current + 1;
 
     long result = iterator->following(current);
     if (result == TextBreakDone)
         result = current + 1;
 
     return result;
 }
 
-bool RenderText::computeCanUseSimpleFontCodePath() const
+bool RenderText::computeCanUseSimpleFontCodePath()

[eseidel, 2013/12/27 04:36:45]

We could also just have made codepath mutable. Unclear which is better.

 {

[eae, 2013/12/30 19:29:14]

This method didn't use to have a side effect and now it does, have you ensured
that this is _always_ called now (to set m_textCodePath) and that additional
calls use the new codePath getter instead?

[h.joshi, 2013/12/31 06:07:43]

This method is always called when RenderText is created and this does not have
issue. It just with new changes we are storing the value returned by the
CodePath search which we were not.

+    m_textCodePath = AutoPath;
     if (isAllASCII() || m_text.is8Bit())
         return true;
-    return Font::characterRangeCodePath(characters16(), length()) == Font::Simple;
+    m_textCodePath = Font::characterRangeCodePath(characters16(), length());
+    return (m_textCodePath == SimplePath);
 }
 
 #ifndef NDEBUG
 
 void RenderText::checkConsistency() const
 {
 #ifdef CHECK_CONSISTENCY
     const InlineTextBox* prev = 0;
     for (const InlineTextBox* child = m_firstTextBox; child != 0; child = child->nextTextBox()) {
         ASSERT(child->renderer() == this);
@@ skipping 18 matching lines @@
     }
     secureTextTimer->restartWithNewText(lastTypedCharacterOffset);
 }
 
 PassRefPtr<AbstractInlineTextBox> RenderText::firstAbstractInlineTextBox()
 {
     return AbstractInlineTextBox::getOrCreate(this, m_firstTextBox);
 }
 
 } // namespace WebCore