umputun / revdiff / 25685776438

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Build Type

push

github

Committed by web-flow

Commit Message

fix: coalesce diff-pane wheel events to unblock reverse scroll (#179) (#180)

* fix: coalesce diff-pane wheel events to unblock reverse scroll (#179)

Rapid wheel events on large diffs previously triggered an O(cursor) pin
plus a full SetContent(renderDiff()) per event, so a trackpad flick
queued ~50 expensive Update+View cycles. A subsequent reverse-direction
wheel event sat at the back of that queue and only took effect once it
drained.

The diff-pane wheel path now only shifts YOffset synchronously and
defers the cursor pin + renderDiff to a single in-flight tea.Tick.
A new wheelState.tickInFlight gate guarantees one debounce goroutine
per burst regardless of event count (the first wheel schedules a tick;
subsequent wheels just bump gen). When the tick fires, handleWheelDebounce
either reschedules for the current gen (burst still going) or flushes
(burst settled). handleKey and handleResize call flushWheelPending up-front
so cursor-relative actions and post-resize scroll see a fresh cursor.

Measured on a 4700-event trackpad burst: debounce messages dropped from
4201 to 560, View() calls 9144 to 5469, total View time 21s to 12.6s.

* fix(review-loop): iteration 1 addressed 11 findings

- [major] loaders.go:364 handleBlameLoaded flushes wheel state before syncViewportToCursor (codex)
- [major] mouse.go:300 handleWheelDebounce godoc — replaced "stale ticks no-op" with accurate three-branch description
- [major] mouse.go:381 flushWheelPending godoc — listed actual callers (handleKey, handleResize, handleBlameLoaded, handleWheelDebounce); dropped false "non-wheel handleMouse" claim
- [major] mouse_test.go RendersOnMatchingGen — now exercises real pin + verifies cursor + tickInFlight transitions
- [major] mouse_test.go NoopWhenRenderNotPending — seeds tickInFlight=true and verifies cleanup
- [major] new test TestModel_HandleKey_FlushesPendingWheelBeforeAction — pins the handleKey flush contract
- [major] new test TestModel_HandleResize_FlushesPendingWhe... (continued)

Coverage Stats

61 of 62 new or added lines in 3 files covered. (98.39%)

1 existing line in 1 file now uncovered.

9752 of 10864 relevant lines covered (89.76%)

3193.43 hits per line