#537 Ongoing durations: an end that is "now"

[Anonymous]

Originally created by: athanclark

Part of [#533]. Open work items (an assigned issue, a card in progress, a shift not yet clocked out), and history such as "2022–present", need a duration whose end is now, still moving, until it is closed.

Proposal

A third kind of duration endpoint, beside a fixed time and {"moment": id}:

{ "id": "issue-412", "start": "1762560000", "end": { "ongoing": true }, "metadata": { "title": "Fix the login loop" } }

• Meaning. The end is the current time. Closing the duration replaces it with a fixed time (or a moment anchor). Only an end may be ongoing.
• Not "uncertain". An end that happened at an unknown time is a precision question and is out of scope here.
• Only where "now" exists. Accepted only on timelines whose time display is Gregorian, where a coordinate maps to Unix seconds through the preset's origin and scale. Elsewhere validation refuses it with a clear message.
• Indexes. An ongoing end is stored as unbounded in the interval trees (browser durationTree, the server's AVL index, native-store/src/intervals.rs), so cached extents never go stale. It is cut off at the current time only when a band is resolved for a window.
• Drawing. The band runs to "now" and ends with a fade or an arrow, so it does not read as ending at the view's edge. The duration dialog gets Ongoing as a third endpoint choice, and its details say "ongoing".
• Formats and API. .ochx, .och (SQLite), the HTTP API and OpenAPI schema, merges and history, and export and conversion (och-convert).
• Summaries. Collapsed-duration summaries and counts treat an ongoing duration as ending now.

Done when

• Ongoing durations round-trip through every format and the API, and are refused on non-Gregorian timelines.
• They draw to the current time and keep growing while the page is open.
• Tests cover validation, the three interval trees, window queries and summaries.
• docs/durations.md describes them.

[Anonymous]

Originally posted by: athanclark

Design

The browser's interval tree is rebuilt in memory, but the server's (oc_duration_nodes, via server/avl.mjs) and the native store's (native-store/src/intervals.rs) are persisted as exact rationals. PostgreSQL computes windows and summaries over them in SQL, through forks and saved views. Neither format has an "infinity" or a clock, so "now" cannot be stored in them.

Stored as a placeholder. An ongoing duration stays a row of the tree, as a zero-length band at its start. Its definition carries "end": {"ongoing": true}. Storage, forks, history, lookup by ID and listing therefore need no schema change.

Resolved at query time. Each window query also reads the timeline's ongoing durations, through a partial index on the definition and with a per-timeline cap. It resolves each against "now", as last = max(start, now), then:

• swaps the resolved band in for its placeholder in the window's longest-first ranking;
• adjusts the counts;
• adds the band to the collapsed summaries when it is shorter than the threshold.

"Now" is the server's clock for server queries and the page's clock in the browser. It is mapped through the Gregorian preset: stored = Unix seconds × scale + origin.

Stages

1. The core model and the browser: validation (Gregorian timelines only), resolution, the in-memory index, drawing, the duration dialog, .ochx. The server refuses ongoing ends until stage 2.
2. The server: storage, window and summary queries, saved views, the API and OpenAPI.
3. The native store and och-convert.