Files
taskgraph_ts/docs/architecture/decisions/002-rebuild-vs-incremental.md
glm-5.1 e592caed57 Add architecture review findings and address documentation issues
Review of all ADR documents (001-007) and peripheral architecture docs
identified 3 critical, 10 warning, and 7 suggestion issues.

Addressed in this commit:
- W-1: Add draft qualifier to ADR-002 reference to incremental exploration
- W-2: Add Alternatives Considered section to ADR-001
- W-3: Add Document Lifecycle section to README.md (draft/stable/deprecated)
- W-4: Clarify includeCompleted semantics (only 'completed' status triggers exclusion)
- W-5: Document file I/O runtime constraints in frontmatter.md
- W-6: Add ADR reference to architecture.md redirect
- W-7: Verify CVE-2025-64718 (confirmed real, improved description)
- W-9: Convert workspace-absolute paths to relative/monorepo references
- S-7: Add future ADR-008 note to incremental-update-exploration.md

Critical issues (C-1, C-2, C-3) and remaining warnings (W-8, W-10, S-4, S-5)
were addressed by a parallel agent in a prior commit.

All 16 review tasks created and resolved.
2026-04-26 09:41:05 +00:00

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ADR-002: Rebuild graph on change, not incremental updates

Status: Accepted

Context

When task data changes (file edits, DB updates), the in-memory graph needs to reflect the new state. Two approaches: incremental updates (add/remove individual nodes/edges) or full rebuild from source data.

Decision

Rebuild. For our graph sizes (10200 nodes), graph.import() from a serialized blob is sub-millisecond. Both consumers (alkhub builds from DB query results; OpenCode plugin rebuilds from directory on file change) are well-served by rebuild.

Consequences

Positive

  • No change-detection layer needed — no tracking ID renames, dependency removals, edge reconciliation
  • Simpler codebase — no diff algorithm, no incremental update logic
  • Always consistent — rebuild guarantees the graph matches the source data exactly

Negative

  • Technically wasteful for small changes (rebuilding entire graph when one task changed)
  • Not suitable for very large graphs or extremely frequent updates

Mitigation

If a future use case requires incremental updates, add it as an optimization then. The API surface (construction methods) supports both patterns — incremental construction exists via addTask/addDependency.

An incremental update architecture has been explored (draft, not yet a decision) in incremental-update-exploration.md. The key finding is that the win is reactivity (fine-grained event notifications), not performance. For <200 node graphs, rebuild is always sub-millisecond. If a consumer needs reactive updates, they can use graphology's event system directly via graph.raw and implement change detection at the consumer layer, without the library taking on the complexity of diff-based updates.