Feat: In-memory KV store with TTL

db.js

@@ -0,0 +1,45 @@
+import { Database } from 'bun:sqlite'
+
+const db = new Database(':memory:', { strict: true })
+
+db.exec(`
+  CREATE TABLE kv (
+    k TEXT PRIMARY KEY,
+    v TEXT NOT NULL,
+    exp INTEGER NOT NULL
+  )
+`)
+
+const stmts = {
+  get: db.prepare('SELECT v FROM kv WHERE k=? AND exp>?'),
+  set: db.prepare('INSERT OR REPLACE INTO kv VALUES (?,?,?)'),
+  del: db.prepare('DELETE FROM kv WHERE k=?'),
+  prune: db.prepare('DELETE FROM kv WHERE exp<?'),
+  list: db.prepare("SELECT k FROM kv WHERE k GLOB ? AND exp>?"),
+}
+
+const TTL_MS = 20 * 60 * 1000
+
+export function get(key) {
+  const row = stmts.get.get(key, Date.now())
+  return row ? JSON.parse(row.v) : null
+}
+
+export function set(key, val, ttl = TTL_MS) {
+  stmts.set.run(key, JSON.stringify(val), Date.now() + ttl)
+}
+
+export function del(key) {
+  stmts.del.run(key)
+}
+
+export function list(prefix) {
+  return stmts.list.all(prefix + '*', Date.now()).map(r => r.k)
+}
+
+export function prune() {
+  stmts.prune.run(Date.now())
+}
+
+// Prune expired entries every 60s
+setInterval(prune, 60_000)