# Phase 7 Performance Final Validation

Date: 2026-06-02

Branch: `codex/perf-phase-4-5-7-renderer-eventlog-final`

## Scope

This report closes the local Phase 7 review for the first performance optimization track. It validates the local implementation state for Phase 0 through Phase 7, records remaining gaps, and decides whether DB or heavy event processing must move to a worker in this stage.

## Local Phase Status

| Phase | Local status | Commit(s) | Notes |
|---|---|---|---|
| Phase 0 - Metrics baseline | Completed | `7e412c0`, `dfd9c39` | Startup, IPC, DB, settings-capable metrics and log export snapshot. |
| Phase 1 - Startup staging | Completed | `56ce52f` | T0/T1/T2 split and background services. |
| Phase 2 - IPC subscribe and coalescing | Completed | `ad7fe54`, `fdc6c71`, `abe4496` | Session subscriptions and stream message coalescing. |
| Phase 3 - DB split and batching | Completed | `070adda`, `60569c3` | Session meta/recent message split, paging, indexes, config transaction. |
| Phase 4 - Renderer heavy rendering | Completed | `1b6b61b` | Long content, long code, tool logs, and large diffs are deferred or collapsed. |
| Phase 5 - Event Log MVP | Completed | `395cd65` | Append-only `cowork_events`, replay helpers, event timeline export summary. |
| Phase 6 - Settings performance | Completed locally | `b8198e5`, `a9d8cae` | Settings lazy diagnostics and slow settings IPC channel attribution. |
| Phase 7 - Final validation | Completed locally | this commit | This report. |

## Verification Run Locally

- `npm test -- renderingGuards`
- `npm test -- coworkEventStore`
- `npm run compile:electron`
- `npm run build`
- Targeted ESLint checks for Phase 4 and Phase 5 changed files

Results:

- Renderer guard tests passed.
- Event log store tests passed.
- Electron main/preload TypeScript compilation passed.
- Production build passed.
- Targeted ESLint checks had no new errors. Existing warnings in large legacy files remain outside this phase.

## Requirement Alignment

Startup:

- Phase 0 added timing capture.
- Phase 1 split foreground startup from background services.
- Remaining validation: measure cold startup and first interactive time after all phase branches are merged into the same base.

IPC and streaming:

- Phase 0 records IPC event rate and payload size.
- Phase 2 adds session subscriptions and coalesces message updates.
- Remaining validation: run a high-frequency stream fixture and confirm per-session IPC rate and payload size in `performance-snapshot.json`.

Database:

- Phase 0 records slow DB operations.
- Phase 3 splits full session loading into meta and paged messages, adds indexes, and batches config saves.
- Phase 5 adds append-only events without switching UI loading to event replay.
- Remaining validation: confirm no main-process DB operation over 100ms during long-session open and streaming fixture runs.

Renderer:

- Phase 4 defers long markdown, long code blocks, large diffs, and long tool output.
- Full list virtualization was not implemented in Phase 4 because recent-window loading plus heavy-content deferral is lower risk and covers the primary blocker first.
- Remaining validation: run the 1000-message fixture and long diff fixture in `electron:dev`.

Settings:

- Phase 6 adds settings performance attribution and reduces eager loading.
- Remaining validation: measure settings open and first tab load timings after merge, especially with OpenClaw missing.

Event log:

- Phase 5 adds append-only event storage, idempotent source event IDs, replay helpers, and a redacted timeline summary in log export.
- UI still reads the existing message view by default, preserving old-session compatibility.

## Deviations

- Full message-list virtualization is not implemented. This is acceptable for the local Phase 4 scope because the current session already uses paged recent messages and the heavy-rendering blockers are now deferred.
- Mermaid-specific viewport lazy rendering is not implemented separately. It remains covered indirectly by long markdown collapse and should move to P1 only if fixture testing still shows Mermaid-specific stalls.
- Permission and runtime metric event types exist in the Event Log API, but not every runtime adapter emits every event type yet. This keeps Phase 5 low risk and leaves broader telemetry wiring for follow-up work.
- The remote PR workflow is not complete in this local branch: per-phase PR creation, six-minute review polling, merging, and pulling latest `main` still need to happen.
- Final numeric P0 performance targets cannot be marked globally complete until all phase branches are merged and measured in one unified codebase.

## Workerization Decision

Decision: do not move DB or event reduction to a worker in this first stage.

Rationale:

- Phase 3 removed the primary synchronous full-session hot path for normal session open by adding meta and paged message reads.
- Phase 5 event replay is available for debug and migration, but the UI is not using raw event reduction as a hot-path renderer input.
- Phase 0 metrics can already identify DB operations over 100ms after merge, so workerization can be triggered by measured regressions rather than added speculatively.

P1 trigger:

- If `performance-snapshot.json` shows repeated DB operations over 100ms during startup, settings open, long-session open, or streaming, create a utility-process DB service design.
- If event replay or timeline reduction becomes a user-facing hot path and blocks the main process, move reducer work to a worker or utility process.

## Required Follow-Up Before Final Merge

- Create PRs directly on `origin` for the phase branches.
- Wait six minutes after each PR, then read all review comments, review threads, PR comments, and check annotations.
- Fix actionable review feedback and push.
- Merge PRs in order and pull latest `main`.
- Re-run `npm run compile:electron`, `npm run build`, and targeted tests on merged `main`.
- Run `npm run electron:dev` with startup, stream, 1000-message, long diff, and settings scenarios.
- Export logs and inspect `performance-snapshot.json` plus `event-timeline-summary.json`.
