Git_Mirror/Terminal.Gui
1
0
Fork 0
mirror of https://github.com/gui-cs/Terminal.Gui.git synced 2025-12-26 15:57:56 +01:00
Code Issues Packages Projects Releases Wiki Activity

Fix TextFormatter.GetDrawRegion per-line allocations using ArrayPool

Browse Source 
Applied ArrayPool pattern to GetDrawRegion method:
- Use ArrayPool<string>.Shared.Rent() instead of .ToArray() for grapheme arrays
- Track actual grapheme count separately from rented array length
- Return array to pool in finally block for guaranteed cleanup
- Handle rare case where array needs to grow during enumeration

Impact: Eliminates allocations on layout calculations
- GetDrawRegion called before drawing for text region calculations
- Same allocation pattern as Draw() which was already fixed
- Complements the Draw() optimization for complete text rendering pipeline

All unit tests pass (12,055 parallelizable + 1,173 non-parallel)

Co-authored-by: tig <585482+tig@users.noreply.github.com>
This commit is contained in:
copilot-swe-agent[bot]
2025-12-03 20:46:45 +00:00
parent 12756a29d8
commit d425e4edbf
1 changed files with 39 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
Terminal.Gui/Text/TextFormatter.cs
View File

@@ -956,10 +956,30 @@ public class TextFormatter
}
string strings = linesFormatted [line];
string [] graphemes = GraphemeHelper.GetGraphemes (strings).ToArray ();
// Use ArrayPool to avoid per-line allocations
int estimatedCount = strings.Length + 10; // Add buffer for grapheme clusters
string [] graphemes = ArrayPool<string>.Shared.Rent (estimatedCount);
var graphemeCount = 0;
// When text is justified, we lost left or right, so we use the direction to align.
int x = 0, y = 0;
try
{
foreach (string grapheme in GraphemeHelper.GetGraphemes (strings))
{
if (graphemeCount >= graphemes.Length)
{
// Need larger array (rare case for complex text)
string [] larger = ArrayPool<string>.Shared.Rent (graphemes.Length * 2);
Array.Copy (graphemes, larger, graphemeCount);
ArrayPool<string>.Shared.Return (graphemes, clearArray: true);
graphemes = larger;
}
graphemes [graphemeCount++] = grapheme;
}
// When text is justified, we lost left or right, so we use the direction to align.
int x = 0, y = 0;
switch (Alignment)
{
@@ -1036,7 +1056,7 @@ public class TextFormatter
{
// Vertical Alignment
case Alignment.End when isVertical:
y = screen.Bottom - graphemes.Length;
y = screen.Bottom - graphemeCount;
break;
case Alignment.End:
@@ -1066,7 +1086,7 @@ public class TextFormatter
}
case Alignment.Center when isVertical:
{
int s = (screen.Height - graphemes.Length) / 2;
int s = (screen.Height - graphemeCount) / 2;
y = screen.Top + s;
break;
@@ -1106,22 +1126,22 @@ public class TextFormatter
continue;
}
if (!FillRemaining && idx > graphemes.Length - 1)
if (!FillRemaining && idx > graphemeCount - 1)
{
break;
}
if ((!isVertical
&& (current - start > maxScreen.Left + maxScreen.Width - screen.X + colOffset
|| (idx < graphemes.Length && graphemes [idx].GetColumns () > screen.Width)))
|| (idx < graphemeCount && graphemes [idx].GetColumns () > screen.Width)))
|| (isVertical
&& ((current > start + size + zeroLengthCount && idx > maxScreen.Top + maxScreen.Height - screen.Y)
|| (idx < graphemes.Length && graphemes [idx].GetColumns () > screen.Width))))
|| (idx < graphemeCount && graphemes [idx].GetColumns () > screen.Width))))
{
break;
}
string text = idx >= 0 && idx < graphemes.Length ? graphemes [idx] : " ";
string text = idx >= 0 && idx < graphemeCount ? graphemes [idx] : " ";
int runeWidth = GetStringWidth (text, TabWidth);
if (isVertical)
@@ -1141,20 +1161,25 @@ public class TextFormatter
current += isVertical && runeWidth > 0 ? 1 : runeWidth;
int nextStringWidth = idx + 1 > -1 && idx + 1 < graphemes.Length
int nextStringWidth = idx + 1 > -1 && idx + 1 < graphemeCount
? graphemes [idx + 1].GetColumns ()
: 0;
if (!isVertical && idx + 1 < graphemes.Length && current + nextStringWidth > start + size)
if (!isVertical && idx + 1 < graphemeCount && current + nextStringWidth > start + size)
{
break;
}
}
// Add the line's drawn region to the overall region
if (lineWidth > 0 && lineHeight > 0)
// Add the line's drawn region to the overall region
if (lineWidth > 0 && lineHeight > 0)
{
drawnRegion.Union (new Rectangle (lineX, lineY, lineWidth, lineHeight));
}
}
finally
{
drawnRegion.Union (new Rectangle (lineX, lineY, lineWidth, lineHeight));
ArrayPool<string>.Shared.Return (graphemes, clearArray: true);
}
}