[SCM] WebKit Debian packaging branch, debian/experimental, updated. upstream/1.3.3-9427-gc2be6fc

[xji at chromium.org]

The following commit has been merged in the debian/experimental branch:
commit 5551cf9afbfe50acb9e8535139e3b74c95048da7
Author: xji at chromium.org <xji at chromium.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date:   Wed Sep 29 17:32:43 2010 +0000

    2010-09-29  Xiaomei Ji  <xji at chromium.org>
    
            Reviewed by David Levin.
    
            Performance improvement for FontLinux.
            https://bugs.webkit.org/show_bug.cgi?id=46374
    
            Reduce new/delete operations by storing the maximum capacity of the glyph
            array and use that value in subsequent HB_ShapeItem calls. (Note that a
            call to HB_ShapeItem may reduce the value of m_item.num_glyphs below the
            capacity.)
    
            Also be consistent with zero'ing the glyph arrays before calling
            HB_ShapeItem.
    
            There is no functionality changes so no new tests are added.
    
            * platform/graphics/chromium/FontLinux.cpp:
            (WebCore::TextRunWalker::createGlyphArrays):
            (WebCore::TextRunWalker::resetGlyphArrays):
            (WebCore::TextRunWalker::shapeGlyphs):
    
    git-svn-id: http://svn.webkit.org/repository/webkit/trunk@68660 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/WebCore/ChangeLog b/WebCore/ChangeLog
index 396afe0..d604bad 100644
--- a/WebCore/ChangeLog
+++ b/WebCore/ChangeLog
@@ -1,3 +1,25 @@
+2010-09-29  Xiaomei Ji  <xji at chromium.org>
+
+        Reviewed by David Levin.
+
+        Performance improvement for FontLinux.
+        https://bugs.webkit.org/show_bug.cgi?id=46374
+
+        Reduce new/delete operations by storing the maximum capacity of the glyph
+        array and use that value in subsequent HB_ShapeItem calls. (Note that a
+        call to HB_ShapeItem may reduce the value of m_item.num_glyphs below the
+        capacity.)
+
+        Also be consistent with zero'ing the glyph arrays before calling 
+        HB_ShapeItem.
+
+        There is no functionality changes so no new tests are added.
+ 
+        * platform/graphics/chromium/FontLinux.cpp:
+        (WebCore::TextRunWalker::createGlyphArrays):
+        (WebCore::TextRunWalker::resetGlyphArrays):
+        (WebCore::TextRunWalker::shapeGlyphs):
+
 2010-09-29  Pavel Podivilov  <podivilov at chromium.org>
 
         Reviewed by Pavel Feldman.
diff --git a/WebCore/platform/graphics/chromium/FontLinux.cpp b/WebCore/platform/graphics/chromium/FontLinux.cpp
index a242523..4d984c4 100644
--- a/WebCore/platform/graphics/chromium/FontLinux.cpp
+++ b/WebCore/platform/graphics/chromium/FontLinux.cpp
@@ -477,26 +477,40 @@ private:
     void createGlyphArrays(int size)
     {
         m_item.glyphs = new HB_Glyph[size];
-        memset(m_item.glyphs, 0, size * sizeof(HB_Glyph));
         m_item.attributes = new HB_GlyphAttributes[size];
-        memset(m_item.attributes, 0, size * sizeof(HB_GlyphAttributes));
         m_item.advances = new HB_Fixed[size];
-        memset(m_item.advances, 0, size * sizeof(HB_Fixed));
         m_item.offsets = new HB_FixedPoint[size];
-        memset(m_item.offsets, 0, size * sizeof(HB_FixedPoint));
 
         m_glyphs16 = new uint16_t[size];
         m_xPositions = new SkScalar[size];
 
         m_item.num_glyphs = size;
+        m_glyphsArrayCapacity = size; // Save the GlyphArrays size.
+        resetGlyphArrays();
     }
 
-    void shapeGlyphs()
+    void resetGlyphArrays()
     {
-        for (;;) {
-            if (HB_ShapeItem(&m_item))
-                break;
+        int size = m_item.num_glyphs;
+        // All the types here don't have pointers. It is safe to reset to
+        // zero unless Harfbuzz breaks the compatibility in the future.
+        memset(m_item.glyphs, 0, size * sizeof(HB_Glyph));
+        memset(m_item.attributes, 0, size * sizeof(HB_GlyphAttributes));
+        memset(m_item.advances, 0, size * sizeof(HB_Fixed));
+        memset(m_item.offsets, 0, size * sizeof(HB_FixedPoint));
+        memset(m_glyphs16, 0, size * sizeof(uint16_t));
+        memset(m_xPositions, 0, size * sizeof(SkScalar));
+    }
 
+    void shapeGlyphs()
+    {
+        // HB_ShapeItem() resets m_item.num_glyphs. If the previous call to
+        // HB_ShapeItem() used less space than was available, the capacity of
+        // the array may be larger than the current value of m_item.num_glyphs. 
+        // So, we need to reset the num_glyphs to the capacity of the array.
+        m_item.num_glyphs = m_glyphsArrayCapacity;
+        resetGlyphArrays();
+        while (!HB_ShapeItem(&m_item)) {
             // We overflowed our arrays. Resize and retry.
             // HB_ShapeItem fills in m_item.num_glyphs with the needed size.
             deleteGlyphArrays();
@@ -597,6 +611,7 @@ private:
     unsigned m_offsetX; // Offset in pixels to the start of the next script run.
     unsigned m_pixelWidth; // Width (in px) of the current script run.
     unsigned m_numCodePoints; // Code points in current script run.
+    unsigned m_glyphsArrayCapacity; // Current size of all the Harfbuzz arrays.
 
     OwnPtr<TextRun> m_normalizedRun;
     OwnArrayPtr<UChar> m_normalizedBuffer; // A buffer for normalized run.

-- 
WebKit Debian packaging