Fix: suppress didSet observer during incremental token merge

In mergeTokensByRowId, each tokensByRowId[rowId] = tokens assignment triggered the didSet observer (Swift Dictionary is a value type), causing tokenAttributedStringsByRowId.removeAll(), clampHorizontalOffsets(), and setNeedsDisplayForVisibleBounds() to fire N times — once per patched row. This defeated the incremental cache invalidation the method intended and multiplied layout work for large token patches. Add a _suppressTokensByRowIdDidSet flag so the didSet observer is skipped during the merge loop. The method already performs its own targeted cache invalidation (removeValue per row) and calls clampHorizontalOffsets() and setNeedsDisplayForVisibleBounds() once at the end.

Cursor Agent committed 6 months ago

Commit e72d3641 parent 9b9fe0d1 file · +4 −0Browse files

Unified · Split

apps/mobile/modules/t3-review-diff/ios/T3ReviewDiffView.swift+4−0

       setNeedsDisplayForVisibleBounds()
     }
   }
+  private var _suppressTokensByRowIdDidSet = false
   var tokensByRowId: [String: [ReviewDiffNativeToken]] = [:] {
     didSet {
+      guard !_suppressTokensByRowIdDidSet else { return }
       tokenAttributedStringsByRowId.removeAll()
       clampHorizontalOffsets()
       setNeedsDisplayForVisibleBounds()
   }
   func mergeTokensByRowId(_ tokensPatch: [String: [ReviewDiffNativeToken]]) {
+    _suppressTokensByRowIdDidSet = true
     tokensPatch.forEach { rowId, tokens in
       tokensByRowId[rowId] = tokens
       tokenAttributedStringsByRowId.removeValue(forKey: rowId)
     }
+    _suppressTokensByRowIdDidSet = false
     clampHorizontalOffsets()
     setNeedsDisplayForVisibleBounds()
   }