fix: coalesce rapid viewport scrolling redraws

2026-10-16 10:15:24 +02:00
parent 08fdf2bd0f
commit 5a8c37b2f2
3 changed files with 90 additions and 0 deletions
@@ -76,6 +76,7 @@ Diff styling checks cover independent snapshot language/shebang/injection detect

 - Undo uses full-buffer snapshots and movement scans the current line. This favors straightforward correctness over large-file performance.
 - Rapid-wheel verification must replay bursts against the running editor and measure arrival at the final viewport after input stops, not just individual frame duration. Cheap frames can still accumulate a visible backlog if each queued report requires its own redraw.
+- Keyboard viewport scrolling coalesces up to 64 consecutive inputs for the same resolved scroll action into one redraw. Reversals, changes between row/half-page scrolling, and cursor motions end the batch so boundary clamping and caret reveal happen before the next action. Burst checks must include direction changes at the start/end of the buffer, not just throughput.
 - PTY throughput alone cannot prove terminal presentation stays smooth: capture the editor and terminal while the user reproduces a pause. Synchronized-output commands must not reach the terminal during frame computation, even when individual frames and queued-input catch-up appear fast.
 - Annotation coordinate validation fast-paths ASCII grapheme lengths using byte lengths with CRLF pair accounting, retaining Unicode segmentation for non-ASCII text. Validation remains atomic and still checks every token; large Unicode buffers or diagnostic batches can require foreground work.
 - Legacy synchronous plugin invocation may pause input for up to 500 ms before a host timeout. Async plugins opt into background replies; pending requests and transport queues are bounded. Config/plugin startup has a 2-second deadline per host. Buffer context/document snapshots must fit within a 4 MiB JSON frame; a too-large frame disables that plugin, not editing.