llm-wiki/docs/graph/performance/2026-06-18-phase-0-2-baseline.md

Phase 0.2 Existing Graph Baseline

Date: 2026-06-18 Branch: codex/large-graph-performance-experience Task: 0.2

Scope

This report captures the current graph behavior and performance baseline before changing graph behavior for the large-graph performance plan.

Verification

Check	Result	Evidence
Graph engine test	Pass	npm run test --workspace=@llm-wiki/graph-engine: 274 tests, 58 suites, 0 failures
Graph engine typecheck	Pass	npm run typecheck --workspace=@llm-wiki/graph-engine
Graph engine build	Pass	npm run build --workspace=@llm-wiki/graph-engine
Workbench web test	Pass	npm run test --workspace=@llm-wiki-agent/web: 29 tests, 12 suites, 0 failures
Workbench web typecheck	Pass	npm run typecheck --workspace=@llm-wiki-agent/web
Stage 4.5 offline browser regression	Pass	GRAPH_STAGE_4_5_CHROME_EXECUTABLE=<Playwright Chromium> bash tests/graph-browser-stage-4-5.regression-1.sh --target offline

Browser Artifact

Dense wheel artifact:

• JSON: docs/graph/performance/artifacts/2026-06-18-phase-0-2/stage-4.5-offline-dense-wheel.json
• Screenshot: docs/graph/performance/artifacts/2026-06-18-phase-0-2/stage-4.5-offline-dense-wheel.png
• Navigation screenshot: docs/graph/performance/artifacts/2026-06-18-phase-0-2/stage-4.5-offline-navigation.png

Recorded sample:

Viewport	Duration	Frames	Idle FPS	Wheel FPS	Minimum FPS	Transform changed
1440x960	3004 ms	157	13.6	52.3	12.0	true

Important limitation: the current dense fixture has 200 nodes and 231 edges. This is useful as a regression baseline, but it does not prove 1000, 5000, or 10000 node smoothness.

Current Rendering Behavior

• The current graph renderer is DOM/SVG.
• Nodes are DOM button elements in a node layer.
• Edges are SVG path elements in an edge layer.
• Community washes are SVG ellipses.
• Pan and zoom are applied through one content-layer transform.
• Motion frames update node positions, edge paths, community wash geometry, and minimap points.
• Search, type filters, community hover, node selection, reader state, and selection panels are all currently coupled to the same DOM/SVG renderer path.

Current Interaction Semantics

The current behavior remains the pre-new-design behavior:

• Plain node click opens the reader-style node detail state.
• Shift-click builds a multi-node selection.
• Community legend click selects/focuses community nodes.
• Blank double-click fits the graph.
• Escape closes reader/selection state and clears graph highlights.
• Offline graph uses an in-graph reader panel; workbench graph opens the right drawer.

This is intentionally recorded as baseline behavior, not as the desired final interaction model.

Baseline Bottleneck Class

The obvious large-graph risk is DOM/SVG update volume.

Reasons:

• Every visible node is a live DOM element.
• Every visible edge is a live SVG path.
• Rebuild/paint replaces the graph root and remounts controls.
• Motion frames recompute renderable graph state and update many DOM/SVG attributes.
• Hover, search, filter, community emphasis, and selection use DOM state/class updates across visible graph elements.

For small and medium scoped views, this is still appropriate. For 5000+ or 10000+ global views, the likely bottleneck is not one single function; it is the total cost of DOM node count, SVG path count, repeated attribute/class writes, and full repaint/remount paths.

Test Harness Note

The first run of tests/graph-browser-stage-4-5.regression-1.sh --target offline exposed two harness issues:

• Playwright's normal click waited indefinitely for the offline theme button to become stable even though the button was visible, stationary, and not covered.
• The script's default system Chrome path failed in this environment during launch/cleanup. Installing Playwright Chromium and setting GRAPH_STAGE_4_5_CHROME_EXECUTABLE to the Playwright browser path produced a passing run.

The theme-button step was adjusted in the test harness to use forced click for this specific control. Product behavior was not changed.

Next Baseline Gap

Phase 1 must add deterministic 1000, 5000, 10000, oversized-community, many-small-communities, many-search-hits, and many-Pin fixtures. Until those measurements exist, this report should be treated as the current small/dense-fixture baseline only.