Perf: save text buffer size to prevent frequent vector access

microsoft · Oct 28, 2019 · dd10a15 · dd10a15
1 parent 634687b
commit dd10a15
Show file tree

Hide file tree

Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/src/buffer/out/textBuffer.cpp b/src/buffer/out/textBuffer.cpp
@@ -33,13 +33,16 @@ TextBuffer::TextBuffer(const COORD screenBufferSize,
     _cursor{ cursorSize, *this },
     _storage{},
     _unicodeStorage{},
+    _size{ Viewport::Empty() },
     _renderTarget{ renderTarget }
 {
     // initialize ROWs
     for (size_t i = 0; i < static_cast<size_t>(screenBufferSize.Y); ++i)
     {
         _storage.emplace_back(static_cast<SHORT>(i), screenBufferSize.X, _currentAttributes, this);
     }
+
+    _UpdateSize();
 }
 
 // Routine Description:
@@ -651,9 +654,10 @@ const SHORT TextBuffer::GetFirstRowIndex() const noexcept
 {
     return _firstRow;
 }
+
 const Viewport TextBuffer::GetSize() const
 {
-    return Viewport::FromDimensions({ 0, 0 }, { gsl::narrow<SHORT>(_storage.at(0).size()), gsl::narrow<SHORT>(_storage.size()) });
+    return _size;
 }
 
 void TextBuffer::_SetFirstRowIndex(const SHORT FirstRowIndex) noexcept
@@ -844,6 +848,9 @@ void TextBuffer::Reset()
         // Also take advantage of the row ID refresh loop to resize the rows in the X dimension
         // and cleanup the UnicodeStorage characters that might fall outside the resized buffer.
         _RefreshRowIDs(newSize.X);
+
+        // Update the buffer size.
+        _UpdateSize();
     }
     CATCH_RETURN();
 
@@ -896,6 +903,11 @@ void TextBuffer::_RefreshRowIDs(std::optional<SHORT> newRowWidth)
     _unicodeStorage.Remap(rowMap, newRowWidth);
 }
 
+void TextBuffer::_UpdateSize()
+{
+    _size = Viewport::FromDimensions({ 0, 0 }, { gsl::narrow<SHORT>(_storage.at(0).size()), gsl::narrow<SHORT>(_storage.size()) });
+}
+
 void TextBuffer::_NotifyPaint(const Viewport& viewport) const
 {
     _renderTarget.TriggerRedraw(viewport);

diff --git a/src/buffer/out/textBuffer.hpp b/src/buffer/out/textBuffer.hpp
@@ -156,13 +156,17 @@ class TextBuffer final
 
     SHORT _firstRow; // indexes top row (not necessarily 0)
 
+    Microsoft::Console::Types::Viewport _size;
+
     TextAttribute _currentAttributes;
 
     // storage location for glyphs that can't fit into the buffer normally
     UnicodeStorage _unicodeStorage;
 
     void _RefreshRowIDs(std::optional<SHORT> newRowWidth);
 
+    void _UpdateSize();
+
     Microsoft::Console::Render::IRenderTarget& _renderTarget;
 
     void _SetFirstRowIndex(const SHORT FirstRowIndex) noexcept;