generated from coulomb/repo-seed
tegwick
b31e9bc337
Bootstrap registry/indexes/capabilities.yaml and migrate helix_forge capability entries owned by this repository for federation publishing.
103 lines
3.4 KiB
Markdown
103 lines
3.4 KiB
Markdown
---
|
|
id: capability.wiki.overlay
|
|
name: Overlay-Before-Mutation Write Path
|
|
summary: Non-destructive edits (draft -> patch -> apply-under-drift) that let read-only, rate-limited, or lossy backends be edited safely without silent remote mutation.
|
|
owner: shard-wiki
|
|
status: draft
|
|
domain: helix_forge
|
|
tags: [wiki, overlay, patch, write-path, conflict, shard-wiki]
|
|
|
|
maturity:
|
|
discovery:
|
|
current: D5
|
|
target: D6
|
|
confidence: high
|
|
rationale: >
|
|
Overlay lifecycle and apply-under-drift semantics are specified (ADR-05, blueprint
|
|
Section 8.6) and implemented as a single principled write path.
|
|
availability:
|
|
current: A2
|
|
target: A4
|
|
confidence: medium
|
|
rationale: >
|
|
OverlayEngine (draft/patch/apply), writable adapter, and InformationSpace.edit
|
|
exist as a source module; three-way merge is not (refuse-on-drift only).
|
|
|
|
external_evidence:
|
|
completeness:
|
|
level: C2
|
|
name: Partial
|
|
confidence: medium
|
|
basis: scope_vs_intent_and_consumer_expectations
|
|
satisfied_expectations:
|
|
- draft -> patch -> apply with fast-forward / refuse-on-drift / keep-draft outcomes
|
|
- no silent remote mutation; overlay_state surfaced in provenance
|
|
broken_expectations:
|
|
- three-way / auto merge not implemented (refuse-on-conflict only)
|
|
out_of_scope_expectations:
|
|
- federation propagation of applied overlays
|
|
reliability:
|
|
level: R1
|
|
confidence: low
|
|
basis: consumer_quality_signals
|
|
known_reliability_risks:
|
|
- early implementation; conflict handling is detect-and-refuse only
|
|
|
|
discovery:
|
|
intent: >
|
|
Make any sub-write-through backend editable safely: an edit is an overlay first, applied
|
|
only on explicit intent and only when the source has not drifted.
|
|
includes:
|
|
- overlay drafts recorded as coordination-canonical events
|
|
- patch rendering (unified diff)
|
|
- apply-under-drift (fast-forward / refuse / keep-draft)
|
|
excludes:
|
|
- destructive write without drift check
|
|
use_cases:
|
|
- "shard-wiki UseCaseCatalog UC-04, UC-26, UC-29 (remix primitives, overlay)"
|
|
|
|
availability:
|
|
current_level: A2
|
|
target_level: A4
|
|
current_artifacts:
|
|
- "shard-wiki/src/shard_wiki/coordination/overlay.py"
|
|
- "shard-wiki/src/shard_wiki/coordination/patch.py"
|
|
consumption_modes:
|
|
- source module
|
|
|
|
relations:
|
|
depends_on:
|
|
- capability.wiki.coordination-journal
|
|
- capability.wiki.adapter-contract
|
|
|
|
evidence:
|
|
documentation:
|
|
- "shard-wiki/spec/FederationRequirements.md (ADR-05)"
|
|
- "shard-wiki/spec/CoreArchitectureBlueprint.md (Section 8.2, 8.6)"
|
|
tests:
|
|
- "shard-wiki/tests/test_apply.py"
|
|
- "shard-wiki/tests/test_write_path_integration.py"
|
|
|
|
consumer_guidance:
|
|
recommended_for:
|
|
- safe editing over read-only / rate-limited / lossy backends
|
|
not_recommended_for:
|
|
- workflows needing automatic conflict resolution today
|
|
known_limitations:
|
|
- merge is detect-and-refuse; three-way merge is future work
|
|
---
|
|
|
|
# Overlay-Before-Mutation Write Path
|
|
|
|
One principled write path: every edit drafts an overlay (a coordination-canonical event),
|
|
renders as a patch, and applies under drift checks — fast-forwarding a writable target,
|
|
keeping a local draft on a read-only target, and refusing (never clobbering) on external drift.
|
|
|
|
## Assessment notes
|
|
|
|
### Discovery
|
|
Specified in FederationRequirements ADR-05 and CoreArchitectureBlueprint Section 8.2/8.6.
|
|
|
|
### Availability
|
|
`overlay.py` + `patch.py` + `InformationSpace.edit` ship the path; built in SHARD-WP-0008.
|