Use glyph-ids for lookups of SVG font kerning-pairs

Source/core/svg/SVGGlyphMap.h

Index: Source/core/svg/SVGGlyphMap.h
diff --git a/Source/core/svg/SVGGlyphMap.h b/Source/core/svg/SVGGlyphMap.h
index 8e20f0644ca99495c52a663c0d664ab0c063bafb..d46489cfd722eeb4238e3d77ac5e67a8893ea63e 100644
--- a/Source/core/svg/SVGGlyphMap.h
+++ b/Source/core/svg/SVGGlyphMap.h
@@ -21,6 +21,7 @@
 #define SVGGlyphMap_h
 
 #if ENABLE(SVG_FONTS)
+#include "core/svg/SVGParserUtilities.h"
 #include "platform/fonts/Latin1TextIterator.h"
 #include "platform/fonts/SVGGlyph.h"
 #include "platform/text/SurrogatePairAwareTextIterator.h"
@@ -49,16 +50,16 @@ class SVGGlyphMap {
 public:
     SVGGlyphMap() : m_currentPriority(0) { }
 
-    void addGlyph(const String& glyphName, const String& unicodeString, SVGGlyph glyph)
+    void addGlyph(const String& glyphIdentifier, const String& unicodeString, SVGGlyph glyph)
     {
-        ASSERT(!glyphName.isEmpty() || !unicodeString.isEmpty());
+        ASSERT(!glyphIdentifier.isEmpty() || !unicodeString.isEmpty());
 
-        bool hasGlyphName = !glyphName.isEmpty();
+        bool hasGlyphIdentifier = !glyphIdentifier.isEmpty();
         if (unicodeString.isEmpty()) {
-            // Register named glyph in the named glyph map and in the glyph table.
-            ASSERT(hasGlyphName);
+            // Register glyphs with 'id's in the id glyph map and in the glyph table.
+            ASSERT(hasGlyphIdentifier);
             appendToGlyphTable(glyph);
-            m_namedGlyphs.add(glyphName, glyph.tableEntry);
+            m_idGlyphs.add(glyphIdentifier, glyph.tableEntry);
             return;
         }
 
@@ -83,8 +84,10 @@ public:
 
         // If the glyph is named, also add it to the named glyph name, and to the glyph table in both cases.
         appendToGlyphTable(lastGlyph);
-        if (hasGlyphName)
-            m_namedGlyphs.add(glyphName, lastGlyph.tableEntry);
+        if (!lastGlyph.glyphName.isEmpty())
+            m_namedGlyphs.add(lastGlyph.glyphName, lastGlyph.tableEntry);
+        if (hasGlyphIdentifier)
+            m_idGlyphs.add(glyphIdentifier, lastGlyph.tableEntry);
     }
 
     void appendToGlyphTable(SVGGlyph& glyph)
@@ -120,13 +123,48 @@ public:
         std::sort(glyphs.begin(), glyphs.end(), compareGlyphPriority);
     }
 
+    void collectGlyphsForStringExact(const String& string, Vector<SVGGlyph>& glyphs) const
+    {
+        unsigned length = string.length();
+
+        if (!length)
+            return;
+
+        RefPtr<GlyphMapNode> node;
+        if (string.is8Bit()) {
+            Latin1TextIterator textIterator(string.characters8(), 0, length, length);
+            node = findNode(textIterator);
+        } else {
+            SurrogatePairAwareTextIterator textIterator(string.characters16(), 0, length, length);
+            node = findNode(textIterator);
+        }
+
+        if (node)
+            glyphs.appendVector(node->glyphs);
+    }
+
+    void collectGlyphsForUnicodeRange(const UnicodeRange& unicodeRange, Vector<SVGGlyph>& glyphs) const
+    {
+        for (unsigned character = unicodeRange.first; character <= unicodeRange.second; ++character) {
+            if (RefPtr<GlyphMapNode> node = m_rootLayer.get(character))
+                glyphs.appendVector(node->glyphs);
+        }
+    }
+
     void clear()
     {
         m_rootLayer.clear();
         m_glyphTable.clear();
+        m_idGlyphs.clear();
+        m_namedGlyphs.clear();
         m_currentPriority = 0;
     }
 
+    void dropNamedGlyphMap()
+    {
+        m_namedGlyphs.clear();
+    }
+
     const SVGGlyph& svgGlyphForGlyph(Glyph glyph) const
     {
         if (!glyph || glyph > m_glyphTable.size()) {
@@ -136,6 +174,11 @@ public:
         return m_glyphTable[glyph - 1];
     }
 
+    const SVGGlyph& glyphIdentifierForAltGlyphReference(const String& glyphIdentifier) const
+    {
+        return svgGlyphForGlyph(m_idGlyphs.get(glyphIdentifier));
+    }
+
     const SVGGlyph& glyphIdentifierForGlyphName(const String& glyphName) const
     {
         return svgGlyphForGlyph(m_namedGlyphs.get(glyphName));
@@ -164,6 +207,25 @@ private:
     }
 
     template<typename Iterator>
+    PassRefPtr<GlyphMapNode> findNode(Iterator& textIterator) const
+    {
+        const GlyphMapLayer* currentLayer = &m_rootLayer;
+
+        RefPtr<GlyphMapNode> node;
+        UChar32 character = 0;
+        unsigned clusterLength = 0;
+        while (textIterator.consume(character, clusterLength)) {
+            node = currentLayer->get(character);
+            if (!node)
+                break;
+            currentLayer = &node->children;
+            textIterator.advance(clusterLength);
+        }
+
+        return node.release();
+    }
+
+    template<typename Iterator>
     void collectGlyphsForIterator(Iterator& textIterator, Vector<SVGGlyph>& glyphs)
     {
         GlyphMapLayer* currentLayer = &m_rootLayer;
@@ -183,6 +245,7 @@ private:
     GlyphMapLayer m_rootLayer;
     Vector<SVGGlyph> m_glyphTable;
     HashMap<String, Glyph> m_namedGlyphs;
+    HashMap<String, Glyph> m_idGlyphs;
     int m_currentPriority;
 };