Files
Module-uo/server/model/shardEvents/shardEvents.model.js
wtclaude fe3251a543 feat(server): port the UO models, utils and schema fragment
The data half of the extraction: 8 model directories, 13 utils, the shard
stream catalog and the 27-table schema fragment with its purge.

server/core.js is what makes the port a one-line import change per file rather
than a signature change per function. Ported code requires its dependencies at
file scope -- `const { query } = require('../../core')` -- which runs before
register() has been called and before any ctx exists. So every member is a
stable function that resolves ctx when CALLED, and nothing may be destructured
off ctx at init either, because core is free to hand over a getter.

Two helpers are vendored rather than taken from ctx, and the line between them
is the point. utils/excerpt.js is core's deriveExcerpt -- nine lines of pure
text handling. Core's sanitiser next to it was NOT copied: a second copy of a
security control diverges silently the moment either is fixed. announceLinks.js
vendors legError and articleUrl the same way, but baseUrl could not be: core's
reads APP_BASE_URL, and §2.7 forbids a module reading core's environment, so it
comes off ctx.site.baseUrl.

The schema fragment is core's 27 shard_*/uo_link_* statements, verbs CREATE,
ALTER and UPDATE only, every CREATE TABLE guarded. Two of its tables carry a
foreign key INTO users, which is allowed and is why the replay order matters --
core's schema is in place before this runs. The reverse never occurs and must
not: it would make core unable to boot without a module installed.

One real port bug caught by the integration run, not by tests: the atlas art
map resolved `../../../db/data`, which pointed at core's tree when this file
lived there and points outside server/ now. A path that happens to resolve is
exactly what survives a green suite, because the absent-file branch returns {}
and looks like the normal case.

Co-Authored-By: Claude <noreply@anthropic.com>
2026-08-11 12:06:26 -05:00

62 lines
2.5 KiB
JavaScript

// Append-only shard event log. The WS ingest dispatcher calls append() for the
// notable kinds; the public/admin read endpoints call list(). The DB layer only
// sees an already-computed dedupe_key so INSERT IGNORE is idempotent across
// WS-reconnect backfill.
const crypto = require('crypto')
const db = require('./shardEvents.db')
const MAX_LIMIT = 1000
const DEFAULT_LIMIT = 100
// Stable stringify — keys sorted — so the dedupe hash is independent of the
// property order the sidecar happened to serialize with.
function stableStringify(value) {
if (value === null || typeof value !== 'object') return JSON.stringify(value)
if (Array.isArray(value)) return `[${value.map(stableStringify).join(',')}]`
const keys = Object.keys(value).sort()
const entries = keys.map((k) => `${JSON.stringify(k)}:${stableStringify(value[k])}`)
return `{${entries.join(',')}}`
}
// dedupe_key = sha256(kind + t + stable-json(payload)), truncated to 40 hex chars.
// This is a content fingerprint for idempotent INSERT IGNORE, not a security value,
// but we use SHA-256 rather than SHA-1 anyway; the truncation keeps it inside the
// CHAR(40) column (160 bits is ample collision resistance for dedupe). Two identical
// events (same kind, same timestamp, same body) collapse to one row.
function dedupeKey(kind, t, payload) {
return crypto
.createHash('sha256')
.update(`${kind}|${t}|${stableStringify(payload)}`)
.digest('hex')
.slice(0, 40)
}
// Append one event. Returns true if a new row was inserted (false = deduped).
async function append({ kind, t, bootId, payload }) {
return db.insertIgnore({ kind, t, bootId, payload, dedupeKey: dedupeKey(kind, t, payload) })
}
function normalizeLimit(limit) {
const n = Number(limit)
if (!Number.isFinite(n) || n <= 0) return DEFAULT_LIMIT
return Math.min(Math.floor(n), MAX_LIMIT)
}
// Recent events, newest first. Each row's JSON payload is parsed back to an
// object. `kinds` (array) restricts to an allowlist; `kind` filters a single kind.
async function list({ kind, kinds, limit } = {}) {
const rows = await db.list({ kind, kinds, limit: normalizeLimit(limit) })
return rows.map((row) => ({
id: row.id,
kind: row.kind,
t: row.t,
bootId: row.boot_id || null,
// mariadb returns JSON columns as strings on some versions; parse defensively.
payload: typeof row.payload === 'string' ? JSON.parse(row.payload) : row.payload,
createdAt: row.created_at,
}))
}
module.exports = { append, list, dedupeKey }