Add fast lookup path for DxFontInfo (#10521)

Fixes the performance regression caused by DxFontInfo. DxFontInfo introduced in #9201
microsoft · Jul 9, 2021 · f339705 · f339705
1 parent f152573
commit f339705
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Showing 3 changed files with 30 additions and 53 deletions.
diff --git a/src/renderer/dx/DxFontInfo.h b/src/renderer/dx/DxFontInfo.h
@@ -79,30 +79,3 @@ namespace Microsoft::Console::Render
         bool _didFallback;
     };
 }
-
-namespace std
-{
-    template<>
-    struct hash<Microsoft::Console::Render::DxFontInfo>
-    {
-        size_t operator()(const Microsoft::Console::Render::DxFontInfo& fontInfo) const noexcept
-        {
-            const size_t h1 = std::hash<std::wstring_view>{}(fontInfo.GetFamilyName());
-            const size_t h2 = std::hash<DWRITE_FONT_WEIGHT>{}(fontInfo.GetWeight());
-            const size_t h3 = std::hash<DWRITE_FONT_STYLE>{}(fontInfo.GetStyle());
-            const size_t h4 = std::hash<DWRITE_FONT_STRETCH>{}(fontInfo.GetStretch());
-            const size_t h5 = std::hash<bool>{}(fontInfo.GetFallback());
-
-            static const auto combine = [](std::initializer_list<size_t> list) {
-                size_t seed = 0;
-                for (auto hash : list)
-                {
-                    seed ^= hash + 0x9e3779b9 + (seed << 6) + (seed >> 2);
-                }
-                return seed;
-            };
-
-            return combine({ h1, h2, h3, h4, h5 });
-        }
-    };
-}
diff --git a/src/renderer/dx/DxFontRenderData.cpp b/src/renderer/dx/DxFontRenderData.cpp
@@ -118,14 +118,14 @@ DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwr
                                                                                                   DWRITE_FONT_STYLE style,
                                                                                                   DWRITE_FONT_STRETCH stretch)
 {
-    DxFontInfo fontInfo = _defaultFontInfo;
-    fontInfo.SetWeight(weight);
-    fontInfo.SetStyle(style);
-    fontInfo.SetStretch(stretch);
-
-    const auto textFormatIt = _textFormatMap.find(fontInfo);
+    const auto textFormatIt = _textFormatMap.find(_ToMapKey(weight, style, stretch));
     if (textFormatIt == _textFormatMap.end())
     {
+        DxFontInfo fontInfo = _defaultFontInfo;
+        fontInfo.SetWeight(weight);
+        fontInfo.SetStyle(style);
+        fontInfo.SetStretch(stretch);
+
         // Create the font with the fractional pixel height size.
         // It should have an integer pixel width by our math.
         // Then below, apply the line spacing to the format to position the floating point pixel height characters
@@ -137,36 +137,36 @@ DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwr
         THROW_IF_FAILED(textFormat->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_NEAR));
         THROW_IF_FAILED(textFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP));
 
-        _textFormatMap.insert({ fontInfo, textFormat });
+        _textFormatMap.emplace(_ToMapKey(weight, style, stretch), textFormat);
         return textFormat;
     }
     else
     {
-        return (*textFormatIt).second;
+        return textFormatIt->second;
     }
 }
 
 [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::FontFaceWithAttribute(DWRITE_FONT_WEIGHT weight,
                                                                                                DWRITE_FONT_STYLE style,
                                                                                                DWRITE_FONT_STRETCH stretch)
 {
-    DxFontInfo fontInfo = _defaultFontInfo;
-    fontInfo.SetWeight(weight);
-    fontInfo.SetStyle(style);
-    fontInfo.SetStretch(stretch);
-
-    const auto fontFaceIt = _fontFaceMap.find(fontInfo);
+    const auto fontFaceIt = _fontFaceMap.find(_ToMapKey(weight, style, stretch));
     if (fontFaceIt == _fontFaceMap.end())
     {
+        DxFontInfo fontInfo = _defaultFontInfo;
+        fontInfo.SetWeight(weight);
+        fontInfo.SetStyle(style);
+        fontInfo.SetStretch(stretch);
+
         std::wstring fontLocaleName = UserLocaleName();
         Microsoft::WRL::ComPtr<IDWriteFontFace1> fontFace = fontInfo.ResolveFontFaceWithFallback(_dwriteFactory.Get(), fontLocaleName);
 
-        _fontFaceMap.insert({ fontInfo, fontFace });
+        _fontFaceMap.emplace(_ToMapKey(weight, style, stretch), fontFace);
         return fontFace;
     }
     else
     {
-        return (*fontFaceIt).second;
+        return fontFaceIt->second;
     }
 }
 

diff --git a/src/renderer/dx/DxFontRenderData.h b/src/renderer/dx/DxFontRenderData.h
@@ -75,26 +75,30 @@ namespace Microsoft::Console::Render
         [[nodiscard]] static HRESULT STDMETHODCALLTYPE s_CalculateBoxEffect(IDWriteTextFormat* format, size_t widthPixels, IDWriteFontFace1* face, float fontScale, IBoxDrawingEffect** effect) noexcept;
 
     private:
-        void _BuildFontRenderData(const FontInfoDesired& desired, FontInfo& actual, const int dpi);
-        Microsoft::WRL::ComPtr<IDWriteTextFormat> _BuildTextFormat(const DxFontInfo fontInfo, const std::wstring_view localeName);
+        using FontAttributeMapKey = uint32_t;
 
-        ::Microsoft::WRL::ComPtr<IDWriteFactory1> _dwriteFactory;
+        // We use this to identify font variants with different attributes.
+        static FontAttributeMapKey _ToMapKey(DWRITE_FONT_WEIGHT weight, DWRITE_FONT_STYLE style, DWRITE_FONT_STRETCH stretch) noexcept
+        {
+            return (weight << 16) | (style << 8) | stretch;
+        };
 
-        ::Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> _dwriteTextAnalyzer;
+        void _BuildFontRenderData(const FontInfoDesired& desired, FontInfo& actual, const int dpi);
+        Microsoft::WRL::ComPtr<IDWriteTextFormat> _BuildTextFormat(const DxFontInfo fontInfo, const std::wstring_view localeName);
 
-        std::unordered_map<DxFontInfo, ::Microsoft::WRL::ComPtr<IDWriteTextFormat>> _textFormatMap;
-        std::unordered_map<DxFontInfo, ::Microsoft::WRL::ComPtr<IDWriteFontFace1>> _fontFaceMap;
+        std::unordered_map<FontAttributeMapKey, ::Microsoft::WRL::ComPtr<IDWriteTextFormat>> _textFormatMap;
+        std::unordered_map<FontAttributeMapKey, ::Microsoft::WRL::ComPtr<IDWriteFontFace1>> _fontFaceMap;
 
         ::Microsoft::WRL::ComPtr<IBoxDrawingEffect> _boxDrawingEffect;
-
         ::Microsoft::WRL::ComPtr<IDWriteFontFallback> _systemFontFallback;
-        mutable ::Microsoft::WRL::ComPtr<IDWriteFontCollection1> _nearbyCollection;
+        ::Microsoft::WRL::ComPtr<IDWriteFactory1> _dwriteFactory;
+        ::Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> _dwriteTextAnalyzer;
+
         std::wstring _userLocaleName;
         DxFontInfo _defaultFontInfo;
-
-        float _fontSize;
         til::size _glyphCell;
         DWRITE_LINE_SPACING _lineSpacing;
         LineMetrics _lineMetrics;
+        float _fontSize;
     };
 }