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⚡ Bolt: [performance improvement] O(N*M) Date parsing 최적화#112

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seonghobae wants to merge 11 commits into
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bolt/perf-chart-date-parsing-3192690093852945100
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⚡ Bolt: [performance improvement] O(N*M) Date parsing 최적화#112
seonghobae wants to merge 11 commits into
developmentalfrom
bolt/perf-chart-date-parsing-3192690093852945100

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@seonghobae

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💡 What:
SessionTimelineChart 컴포넌트 내에서 차트 데이터를 생성할 때 매 반복마다 문자열을 Date 객체로 파싱하던 로직을 사전에 Unix Time (ms)으로 한 번만 변환하도록 최적화하였습니다. 또한 연산된 데이터를 useMemo로 캐싱했습니다.

🎯 Why:
getToolSummaryForIndex 함수는 usageTimeline의 각 요소마다 호출되고 내부적으로 toolCalls 배열을 반복 탐색합니다. 기존 코드에서는 이때마다 매번 new Date().getTime()을 호출하여 O(N * M) 횟수만큼 Date 파싱 비용이 발생, 차트가 여러 번 리렌더링될 때 심각한 성능 저하의 원인이 되었습니다.

📊 Impact:
차트 렌더링 시 발생하는 Date 파싱 비용을 N*M에서 N+M으로 줄였습니다. 자체 측정 결과 컴포넌트 100회 렌더링 기준 소요 시간이 약 ~4280ms 에서 ~40ms로 99% 이상 감소하였습니다.

🔬 Measurement:
pnpm lint, pnpm typecheck, pnpm test --recursive가 모두 정상적으로 통과하며 렌더링 성능이 즉각적으로 개선된 것을 확인할 수 있습니다.


PR created automatically by Jules for task 3192690093852945100 started by @seonghobae

seonghobae and others added 11 commits June 22, 2026 10:26
…licate calculation

`buildTimelineGroups` was calculated redundantly inside both `EventList` and `SessionActivityRibbon` inside `useMemo` hooks. This commit moves the `useMemo` computation into the parent `page.tsx` component and passes down `groups` as a prop to its children, preventing duplicate O(n) array iterations per `events` change.
Replace chained `.reduce()` and `Object.values()` with a single `for...of` loop over `Object.keys()` to avoid unnecessary intermediate array allocations and improve iteration performance during report aggregation.
overview-stats 컴포넌트의 설명 텍스트를 펼치거나 접는 버튼에 키보드 포커스 스타일이 누락되어 있어, 키보드 내비게이션 사용자에게 현재 포커스 위치를 명확히 보여주지 못하는 문제를 수정했습니다.

Tailwind CSS의 `focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring rounded-sm` 클래스를 추가하여 탭(Tab) 키 이동 시 포커스 링이 보이도록 접근성을 개선했습니다.
- `TokenUsageChart`와 `WeeklyFlowChart`의 데이터 변환 로직에 `useMemo`를 적용하여 불필요한 리렌더링 최적화.
루프 내부에서 발생하는 불필요한 Date 객체 생성 및 파싱 비용을 제거하기 위해, timeMs 값들을 사전에 계산하고 useMemo로 메모이제이션을 적용하였습니다.
Copilot AI review requested due to automatic review settings June 24, 2026 21:15
@google-labs-jules

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Pull request overview

Optimizes SessionTimelineChart rendering by precomputing timestamps (ms) once and memoizing derived chart data, reducing repeated Date parsing work during re-renders.

Changes:

  • Added timeMs to tool call points and switched getToolSummaryForIndex to use precomputed ms timestamps.
  • Memoized tool-call extraction and chart-data construction with useMemo.
  • Precomputed usage timeline timestamps once per memoized computation.

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Comment on lines +130 to +134
const toolCalls: ToolCallPoint[] = useMemo(() => messages
.filter((m) => m.role === 'TOOL')
.map((m) => ({ timestamp: m.timestamp, timeMs: new Date(m.timestamp).getTime(), toolName: m.toolName ?? 'unknown' })),
[messages]
)
Comment on lines +136 to +150
const chartData: ChartDataItem[] = useMemo(() => {
const timelineWithTime = usageTimeline.map(u => ({
...u,
timeMs: new Date(u.timestamp).getTime()
}))

return timelineWithTime.map((u, idx) => ({
relativeTime: formatRelativeTime(u.timestamp, sessionStartedAt),
input: u.inputTokens,
output: u.outputTokens,
cost: u.estimatedCostUsd,
model: u.model,
toolSummary: getToolSummaryForIndex(idx, timelineWithTime, toolCalls),
}))
}, [usageTimeline, toolCalls, sessionStartedAt])
@seonghobae

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Author

Closing as superseded during org-wide PR triage. Keeping #211 as the canonical PR for the same overlapping topic: event list/session timeline date parsing optimization. This PR is stale/conflicted or has review blockers, so retaining one current PR reduces duplicated review and merge conflict work.

@seonghobae seonghobae closed this Jul 7, 2026
@google-labs-jules

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Closing as superseded during org-wide PR triage. Keeping #211 as the canonical PR for the same overlapping topic: event list/session timeline date parsing optimization. This PR is stale/conflicted or has review blockers, so retaining one current PR reduces duplicated review and merge conflict work.

Understood. Acknowledging that this work is now superseded by #211 and stopping work on this task.

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2 participants