Add keep/do-not-delete flag for snapshots #144

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opened 2026-08-12 07:25:48 +00:00 by agent-pi · 1 comment

agent-pi commented

2026-08-12 07:25:48 +00:00

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The web UI should allow marking snapshots or events as "keep" / "do not delete". This requires:

A keep boolean column in the snapshots table (or a separate protected_snapshots table)
A web UI toggle (button or checkbox) on the day view and/or scrubber view
The cleanup daemon must skip protected snapshots during retention deletion
Requires DB write access from cangjian (connection is already read-write per the process split design)

This was intentionally deferred during the process split (#143) to keep scope tight.

The web UI should allow marking snapshots or events as "keep" / "do not delete". This requires: - A `keep` boolean column in the snapshots table (or a separate protected_snapshots table) - A web UI toggle (button or checkbox) on the day view and/or scrubber view - The cleanup daemon must skip protected snapshots during retention deletion - Requires DB write access from cangjian (connection is already read-write per the process split design) This was intentionally deferred during the process split (#143) to keep scope tight.

agent-pi commented

2026-09-07 04:46:14 +00:00

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Findings from exploration

src/cang/web/templates/_keep_btn.html is orphaned scaffolding from the original app commit (8b032bf) — it references a defunct clips concept (/clips/{id}/keep); no route renders it. It will be replaced with the real button.
Every motion snapshot belongs to exactly one journey (the group_events_* grouping is total over motion snapshots), so keep semantics are deterministic: motion frame → keep its whole journey; background frame → keep just that frame. No mixed states.
Retention deletion is concentrated in delete_expired_snapshots() (db.py); the daemon just unlinks returned paths, so one AND keep = 0 in both branches is sufficient.
Schema choice: keep boolean column on snapshots (issue option 1) — a separate protected table would force a NOT EXISTS join into cleanup for no benefit.

Plan of attack (design approved in chat with Marvin8):

V6 migration: ALTER TABLE snapshots ADD COLUMN keep INTEGER NOT NULL DEFAULT 0 + set_keep() db helper.
delete_expired_snapshots() skips keep = 1 rows (motion + background).
POST /snapshots/{snapshot_id}/keep — toggle; recomputes the day's journeys with configured journey_gap_seconds, keeps the containing journey or the single background frame; returns JSON {kept: [ids], keep: bool}.
Scrubber (primary surface): keep array in snapshots_json, Keep/Unkeep button beside Prev/Play/Next (fetch-driven), kept-variant motion markers on the density track.
Day view (secondary): Keep/Unkeep button per event tile + "kept" badge for kept journeys.
TDD throughout; docs in docs/web-ui.md; Release-Notes bullet.

**Findings from exploration** - `src/cang/web/templates/_keep_btn.html` is orphaned scaffolding from the original app commit (8b032bf) — it references a defunct `clips` concept (`/clips/{id}/keep`); no route renders it. It will be replaced with the real button. - Every motion snapshot belongs to exactly one journey (the `group_events_*` grouping is total over motion snapshots), so keep semantics are deterministic: **motion frame → keep its whole journey; background frame → keep just that frame**. No mixed states. - Retention deletion is concentrated in `delete_expired_snapshots()` (db.py); the daemon just unlinks returned paths, so one `AND keep = 0` in both branches is sufficient. - Schema choice: `keep` boolean column on `snapshots` (issue option 1) — a separate protected table would force a `NOT EXISTS` join into cleanup for no benefit. **Plan of attack** (design approved in chat with Marvin8): 1. V6 migration: `ALTER TABLE snapshots ADD COLUMN keep INTEGER NOT NULL DEFAULT 0` + `set_keep()` db helper. 2. `delete_expired_snapshots()` skips `keep = 1` rows (motion + background). 3. `POST /snapshots/{snapshot_id}/keep` — toggle; recomputes the day's journeys with configured `journey_gap_seconds`, keeps the containing journey or the single background frame; returns JSON `{kept: [ids], keep: bool}`. 4. Scrubber (primary surface): `keep` array in `snapshots_json`, Keep/Unkeep button beside Prev/Play/Next (fetch-driven), kept-variant motion markers on the density track. 5. Day view (secondary): Keep/Unkeep button per event tile + "kept" badge for kept journeys. 6. TDD throughout; docs in `docs/web-ui.md`; Release-Notes bullet.

agent-pi referenced this issue from a pull request that will close it,

2026-09-07 05:04:19 +00:00

Add keep flag to protect snapshots from retention cleanup #148

agent-pi closed this issue

2026-09-07 08:18:58 +00:00