Restore gfxPangoFontCache to see if this resolves Tp slip from previous change.

gfx/thebes/public/gfxPangoFonts.h

@@ -54,6 +54,9 @@
 // anything other than simple Latin work though!
 //#define ENABLE_FAST_PATH_ALWAYS
 
+#include "nsDataHashtable.h"
+#include "nsClassHashtable.h"
+
 class gfxPangoTextRun;
 
 class gfxPangoFont : public gfxFont {
@@ -156,4 +159,43 @@ protected:
                                 void *closure);
 };
 
+class gfxPangoFontWrapper {
+public:
+    gfxPangoFontWrapper(PangoFont *aFont) {
+        mFont = aFont;
+        g_object_ref(mFont);
+    }
+    ~gfxPangoFontWrapper() {
+        if (mFont)
+            g_object_unref(mFont);
+    }
+    PangoFont* Get() { return mFont; }
+private:
+    PangoFont *mFont;
+};
+
+class gfxPangoFontCache
+{
+public:
+    gfxPangoFontCache();
+    ~gfxPangoFontCache();
+
+    static gfxPangoFontCache* GetPangoFontCache() {
+        if (!sPangoFontCache)
+            sPangoFontCache = new gfxPangoFontCache();
+        return sPangoFontCache;
+    }
+    static void Shutdown() {
+        if (sPangoFontCache)
+            delete sPangoFontCache;
+        sPangoFontCache = nsnull;
+    }
+
+    void Put(const PangoFontDescription *aFontDesc, PangoFont *aPangoFont);
+    PangoFont* Get(const PangoFontDescription *aFontDesc);
+private:
+    static gfxPangoFontCache *sPangoFontCache;
+    nsClassHashtable<nsUint32HashKey,  gfxPangoFontWrapper> mPangoFonts;
+};
+
 #endif /* GFX_PANGOFONTS_H */

gfx/thebes/src/gfxPangoFonts.cpp

@@ -94,6 +94,8 @@
 
 static PangoLanguage *GetPangoLanguage(const nsACString& aLangGroup);
 
+/* static */ gfxPangoFontCache* gfxPangoFontCache::sPangoFontCache = nsnull;
+
 /**
  ** gfxPangoFontGroup
  **/
@@ -207,6 +209,8 @@ gfxPangoFont::~gfxPangoFont()
 /* static */ void
 gfxPangoFont::Shutdown()
 {
+    gfxPangoFontCache::Shutdown();
+
     // This just cleans up memory used by Pango's caches and may cause an
     // assert and crash in cairo (Bug 399556), so only do this when we care
     // about cleaning up memory on shutdown.
@@ -280,6 +284,22 @@ ThebesStyleToPangoWeight (const gfxFontStyle *fs)
     return (PangoWeight)fcWeights[fcWeight];
 }
 
+static PangoFont*
+LoadPangoFont(PangoContext *aPangoCtx, const PangoFontDescription *aPangoFontDesc)
+{
+    gfxPangoFontCache *cache = gfxPangoFontCache::GetPangoFontCache();
+    if (!cache)
+        return nsnull; // Error
+    PangoFont* pangoFont = cache->Get(aPangoFontDesc);
+    if (!pangoFont) {
+        pangoFont = pango_context_load_font(aPangoCtx, aPangoFontDesc);
+        if (pangoFont) {
+            cache->Put(aPangoFontDesc, pangoFont);
+        }
+    }
+    return pangoFont;
+}
+
 void
 gfxPangoFont::RealizePangoFont()
 {
@@ -302,24 +322,23 @@ gfxPangoFont::RealizePangoFont()
             pango_context_set_language(pangoCtx, lang);
     }
 
-
     gfxFloat size = GetStyle()->size;
     pango_font_description_set_absolute_size(pangoFontDesc, size * PANGO_SCALE);
-    mPangoFont = pango_context_load_font(pangoCtx, pangoFontDesc);
+    mPangoFont = LoadPangoFont(pangoCtx, pangoFontDesc);
 
     // Checking mPangoFont to avoid infinite recursion through GetCharSize
     if (size != 0.0 && GetStyle()->sizeAdjust != 0.0 && mPangoFont) {
         // Could try xHeight from TrueType/OpenType fonts.
-        gfxSize isz, lsz;
-        GetCharSize('x', isz, lsz);
+    gfxSize isz, lsz;
+    GetCharSize('x', isz, lsz);
         if (isz.height != 0.0) {
             gfxFloat aspect = isz.height / size;
             size = GetStyle()->GetAdjustedSize(aspect);
 
             pango_font_description_set_absolute_size(pangoFontDesc,
                                                      size * PANGO_SCALE);
-            g_object_unref(mPangoFont);
-            mPangoFont = pango_context_load_font(pangoCtx, pangoFontDesc);
+        g_object_unref(mPangoFont);
+            mPangoFont = LoadPangoFont(pangoCtx, pangoFontDesc);
         }
     }
 
@@ -1447,3 +1466,36 @@ static const MozPangoLangGroup PangoAllLangGroup[] = {
 };
 
 #define NUM_PANGO_ALL_LANG_GROUPS (G_N_ELEMENTS (PangoAllLangGroup))
+
+gfxPangoFontCache::gfxPangoFontCache()
+{
+    mPangoFonts.Init(500);
+}
+
+gfxPangoFontCache::~gfxPangoFontCache()
+{
+}
+
+void
+gfxPangoFontCache::Put(const PangoFontDescription *aFontDesc, PangoFont *aPangoFont)
+{
+    if (mPangoFonts.Count() > 5000)
+        mPangoFonts.Clear();
+    PRUint32 key = pango_font_description_hash(aFontDesc);
+    gfxPangoFontWrapper *value = new gfxPangoFontWrapper(aPangoFont);
+    if (!value)
+        return;
+    mPangoFonts.Put(key, value);
+}
+
+PangoFont*
+gfxPangoFontCache::Get(const PangoFontDescription *aFontDesc)
+{
+    PRUint32 key = pango_font_description_hash(aFontDesc);
+    gfxPangoFontWrapper *value;
+    if (!mPangoFonts.Get(key, &value))
+        return nsnull;
+    PangoFont *font = value->Get();
+    g_object_ref(font);
+    return font;
+}