Avoid extra FontRenderParams queries in RenderTextHarfBuzz.

ui/gfx/render_text_harfbuzz.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <limits>
 #include <map>
 
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 1052 matching lines @@
   const size_t num_runs = runs_.size();
   std::vector<UBiDiLevel> levels(num_runs);
   for (size_t i = 0; i < num_runs; ++i)
     levels[i] = runs_[i]->level;
   visual_to_logical_.resize(num_runs);
   ubidi_reorderVisual(&levels[0], num_runs, &visual_to_logical_[0]);
   logical_to_visual_.resize(num_runs);
   ubidi_reorderLogical(&levels[0], num_runs, &logical_to_visual_[0]);
 }
 
+bool RenderTextHarfBuzz::CompareFamily(
+    internal::TextRunHarfBuzz* run,
+    const std::string& family,
+    const gfx::FontRenderParams& render_params,
+    std::string* best_family,
+    gfx::FontRenderParams* best_render_params,
+    size_t* best_missing_glyphs) {
+  if (!ShapeRunWithFont(run, family, render_params))
+    return false;
+
+  const size_t missing_glyphs = run->CountMissingGlyphs();
+  if (missing_glyphs < *best_missing_glyphs) {
+    *best_family = family;
+    *best_render_params = render_params;
+    *best_missing_glyphs = missing_glyphs;
+  }
+  return missing_glyphs == 0;
+}
+
 void RenderTextHarfBuzz::ShapeRun(internal::TextRunHarfBuzz* run) {
   const Font& primary_font = font_list().GetPrimaryFont();
-  const std::string primary_font_name = primary_font.GetFontName();
   run->font_size = primary_font.GetFontSize();
 
-  size_t best_font_missing = std::numeric_limits<size_t>::max();
-  std::string best_font;
-  std::string current_font;
+  std::string best_family;
+  FontRenderParams best_render_params;
+  size_t best_missing_glyphs = std::numeric_limits<size_t>::max();
 
-  // Try shaping with |primary_font|.
-  if (ShapeRunWithFont(run, primary_font_name)) {
-    current_font = primary_font_name;
-    size_t current_missing = run->CountMissingGlyphs();
-    if (current_missing == 0)
-      return;
-    if (current_missing < best_font_missing) {
-      best_font_missing = current_missing;
-      best_font = current_font;
-    }
-  }
+  if (CompareFamily(run, primary_font.GetFontName(),
+                    primary_font.GetFontRenderParams(),
+                    &best_family, &best_render_params, &best_missing_glyphs))
+    return;
 
 #if defined(OS_WIN)
   Font uniscribe_font;
   const base::char16* run_text = &(GetLayoutText()[run->range.start()]);
   if (GetUniscribeFallbackFont(primary_font, run_text, run->range.length(),
                                &uniscribe_font) &&
-      ShapeRunWithFont(run, uniscribe_font.GetFontName())) {
-    current_font = uniscribe_font.GetFontName();
-    size_t current_missing = run->CountMissingGlyphs();
-    if (current_missing == 0)
-      return;
-    if (current_missing < best_font_missing) {
-      best_font_missing = current_missing;
-      best_font = current_font;
-    }
-  }
+      CompareFamily(run, uniscribe_font.GetFontName(),
+                    uniscribe_font.GetFontRenderParams(),
+                    &best_family, &best_render_params, &best_missing_glyphs))
+    return;
 #endif
 
-  // Try shaping with the fonts in the fallback list except the first, which is
-  // |primary_font|.
-  std::vector<std::string> fonts = GetFallbackFontFamilies(primary_font_name);
-  for (size_t i = 1; i < fonts.size(); ++i) {
-    if (!ShapeRunWithFont(run, fonts[i]))
-      continue;
-    current_font = fonts[i];
-    size_t current_missing = run->CountMissingGlyphs();
-    if (current_missing == 0)
+  // Skip the first fallback font, which is |primary_font|.
+  std::vector<std::string> fallback_families =
+      GetFallbackFontFamilies(primary_font.GetFontName());
+  for (size_t i = 1; i < fallback_families.size(); ++i) {
+    FontRenderParamsQuery query(false);
+    query.families.push_back(fallback_families[i]);
+    query.pixel_size = run->font_size;
+    query.style = run->font_style;
+    FontRenderParams fallback_render_params = GetFontRenderParams(query, NULL);
+    if (CompareFamily(run, fallback_families[i], fallback_render_params,
+                      &best_family, &best_render_params, &best_missing_glyphs))
       return;
-    if (current_missing < best_font_missing) {
-      best_font_missing = current_missing;
-      best_font = current_font;
-    }
   }
 
-  if (!best_font.empty() &&
-      (best_font == current_font || ShapeRunWithFont(run, best_font))) {
+  if (!best_family.empty() &&
+      (best_family == run->family ||
+       ShapeRunWithFont(run, best_family, best_render_params)))
     return;
-  }
 
   run->glyph_count = 0;
   run->width = 0.0f;
 }
 
 bool RenderTextHarfBuzz::ShapeRunWithFont(internal::TextRunHarfBuzz* run,
-                                          const std::string& font_family) {
+                                          const std::string& font_family,
+                                          const FontRenderParams& params) {
   const base::string16& text = GetLayoutText();
   skia::RefPtr<SkTypeface> skia_face =
       internal::CreateSkiaTypeface(font_family, run->font_style);
   if (skia_face == NULL)
     return false;
   run->skia_face = skia_face;
-  FontRenderParamsQuery query(false);
-  query.families.push_back(font_family);
-  query.pixel_size = run->font_size;
-  query.style = run->font_style;
-  run->render_params = GetFontRenderParams(query, NULL);
+  run->family = font_family;
+  run->render_params = params;
   hb_font_t* harfbuzz_font = CreateHarfBuzzFont(
       run->skia_face.get(), SkIntToScalar(run->font_size), run->render_params,
       background_is_transparent());
 
   // Create a HarfBuzz buffer and add the string to be shaped. The HarfBuzz
   // buffer holds our text, run information to be used by the shaping engine,
   // and the resulting glyph data.
   hb_buffer_t* buffer = hb_buffer_create();
   hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16*>(text.c_str()),
                       text.length(), run->range.start(), run->range.length());
@@ skipping 30 matching lines @@
       run->width = std::floor(run->width + 0.5f);
 #endif
   }
 
   hb_buffer_destroy(buffer);
   hb_font_destroy(harfbuzz_font);
   return true;
 }
 
 }  // namespace gfx