Linux: change Skia's fontconfig code to cache SkTypeface objects.

skia/ports/SkFontHost_fontconfig.cpp

 /* libs/graphics/ports/SkFontHost_fontconfig.cpp
 **
 ** Copyright 2008, Google Inc.
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
@@ skipping 37 matching lines @@
 // filenames to fileid numbers and back.
 //
 // Note that there's also a unique id in the SkTypeface. This is unique over
 // both filename and style. Thus we encode that id as (fileid << 8) | style.
 // Although truetype fonts can support multiple faces in a single file, at the
 // moment Skia doesn't.
 // -----------------------------------------------------------------------------
 static SkMutex global_fc_map_lock;
 static std::map<std::string, unsigned> global_fc_map;
 static std::map<unsigned, std::string> global_fc_map_inverted;
+static std::map<uint32_t, SkTypeface *> global_fc_typefaces;
 static unsigned global_fc_map_next_id = 0;
 
 // This is the maximum size of the font cache.
 static const unsigned kFontCacheMemoryBudget = 2 * 1024 * 1024;  // 2MB
 
 static unsigned UniqueIdToFileId(unsigned uniqueid)
 {
     return uniqueid >> 8;
 }
 
@@ skipping 207 matching lines @@
     if (FcPatternGetString(match, FC_FILE, 0, &filename) != FcResultMatch) {
         FcPatternDestroy(match);
         return NULL;
     }
     // Now @filename is pointing into @match
 
     const unsigned fileid = FileIdFromFilename(reinterpret_cast<char*>(filename));
     const unsigned id = FileIdAndStyleToUniqueId(fileid, style);
     SkTypeface* typeface = SkNEW_ARGS(FontConfigTypeface, (style, id));
     FcPatternDestroy(match);
+
+    {
+      SkAutoMutexAcquire ac(global_fc_map_lock);
+      global_fc_typefaces[id] = typeface;
+    }
+
     return typeface;
 }
 
 SkTypeface* SkFontHost::ResolveTypeface(uint32_t id)
 {
     SkAutoMutexAcquire ac(global_fc_map_lock);
-    const SkTypeface::Style style = UniqueIdToStyle(id);
-    const unsigned fileid = UniqueIdToFileId(id);
+    const std::map<uint32_t, SkTypeface *>::iterator
+      i = global_fc_typefaces.find(id);
 
-    std::map<unsigned, std::string>::const_iterator i =
-        global_fc_map_inverted.find(fileid);
-    if (i == global_fc_map_inverted.end())
-        return NULL;
-
-    return SkNEW_ARGS(FontConfigTypeface, (style, id));
+    if (i == global_fc_typefaces.end())
+      return NULL;
+    return i->second;
 }
 
 SkStream* SkFontHost::OpenStream(uint32_t id)
 {
     SkAutoMutexAcquire ac(global_fc_map_lock);
     const unsigned fileid = UniqueIdToFileId(id);
 
     std::map<unsigned, std::string>::const_iterator i =
         global_fc_map_inverted.find(fileid);
     if (i == global_fc_map_inverted.end())
@@ skipping 54 matching lines @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
 size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar)
 {
     if (sizeAllocatedSoFar > kFontCacheMemoryBudget)
         return sizeAllocatedSoFar - kFontCacheMemoryBudget;
     else
         return 0;   // nothing to do
 }