| 1 | /** |
| 2 | * In-process registry of long-running generation tasks (video frames, audio). |
| 3 | * |
| 4 | * The point: a generation must NOT die when the browser navigates away or the |
| 5 | * SSE connection drops. Previously each generate endpoint streamed straight to |
| 6 | * the request's `res`; closing it (switching project / refresh) killed the run. |
| 7 | * |
| 8 | * Now a task runs detached from any request. It accumulates its events, so a |
| 9 | * client can (re)subscribe at any time and get a full replay + live tail. The |
| 10 | * runner's promise drives the work; subscribers come and go freely. |
| 11 | * |
| 12 | * In-memory only — tasks live for the studio process lifetime. A server restart |
| 13 | * loses in-flight tasks (acceptable: the studio is a local single-process tool). |
| 14 | */ |
| 15 | |
| 16 | export type TaskKind = 'message' | 'audio'; |
| 17 | export type TaskStatus = 'running' | 'done' | 'failed'; |
| 18 | |
| 19 | export interface TaskEvent { |
| 20 | /** Monotonic per-task sequence, so a reconnecting client can skip what it saw. */ |
| 21 | seq: number; |
| 22 | data: unknown; |
| 23 | } |
| 24 | |
| 25 | interface Task { |
| 26 | id: string; |
| 27 | projectId: string; |
| 28 | kind: TaskKind; |
| 29 | status: TaskStatus; |
| 30 | events: TaskEvent[]; |
| 31 | subscribers: Set<(e: TaskEvent) => void>; |
| 32 | error?: string; |
| 33 | startedAt: number; |
| 34 | endedAt?: number; |
| 35 | } |
| 36 | |
| 37 | /** Emit handle handed to a task runner — it just calls emit(data). */ |
| 38 | export interface TaskEmitter { |
| 39 | taskId: string; |
| 40 | emit: (data: unknown) => void; |
| 41 | } |
| 42 | |
| 43 | export class TaskRegistry { |
| 44 | private tasks = new Map<string, Task>(); |
| 45 | private seq = 0; |
| 46 | private idCounter = 0; |
| 47 | |
| 48 | /** Tasks completed > this long ago are pruned on the next create(). */ |
| 49 | private static readonly TTL_MS = 10 * 60_000; |
| 50 | |
| 51 | /** |
| 52 | * Start a detached task. `runner` receives an emitter; whatever it emits is |
| 53 | * fanned out to current subscribers AND retained for replay. The runner's |
| 54 | * resolved value is ignored (state lives in emitted events + the project); |
| 55 | * a thrown error marks the task failed and is emitted as a final event. |
| 56 | */ |
| 57 | create( |
| 58 | projectId: string, |
| 59 | kind: TaskKind, |
| 60 | runner: (emitter: TaskEmitter) => Promise<void>, |
| 61 | ): string { |
| 62 | this.prune(); |
| 63 | const id = `task_${Date.now().toString(36)}_${(this.idCounter++).toString(36)}`; |
| 64 | const task: Task = { |
| 65 | id, |
| 66 | projectId, |
| 67 | kind, |
| 68 | status: 'running', |
| 69 | events: [], |
| 70 | subscribers: new Set(), |
| 71 | startedAt: Date.now(), |
| 72 | }; |
| 73 | this.tasks.set(id, task); |
| 74 | |
| 75 | const emit = (data: unknown) => { |
| 76 | const ev: TaskEvent = { seq: ++this.seq, data }; |
| 77 | task.events.push(ev); |
| 78 | for (const fn of task.subscribers) { |
| 79 | try { fn(ev); } catch { /* a dead subscriber shouldn't break the task */ } |
| 80 | } |
| 81 | }; |
| 82 | |
| 83 | // Run detached. Never rejects out of here. |
| 84 | void runner({ taskId: id, emit }) |
| 85 | .then(() => { |
| 86 | task.status = 'done'; |
| 87 | task.endedAt = Date.now(); |
| 88 | emit({ type: 'task_done' }); |
| 89 | }) |
| 90 | .catch((err: unknown) => { |
| 91 | task.status = 'failed'; |
| 92 | task.error = err instanceof Error ? err.message : String(err); |
| 93 | task.endedAt = Date.now(); |
| 94 | emit({ type: 'task_failed', message: task.error }); |
| 95 | }); |
| 96 | |
| 97 | return id; |
| 98 | } |
| 99 | |
| 100 | /** The newest still-running (or just-finished) task for a project, if any. */ |
| 101 | activeTaskFor(projectId: string): { id: string; kind: TaskKind; status: TaskStatus } | null { |
| 102 | let newest: Task | null = null; |
| 103 | for (const t of this.tasks.values()) { |
| 104 | if (t.projectId !== projectId) continue; |
| 105 | if (!newest || t.startedAt > newest.startedAt) newest = t; |
| 106 | } |
| 107 | if (!newest) return null; |
| 108 | return { id: newest.id, kind: newest.kind, status: newest.status }; |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * Subscribe to a task: immediately replays events after `sinceSeq`, then calls |
| 113 | * `onEvent` for each new one. Returns an unsubscribe fn, plus whether the task |
| 114 | * is already finished (so the caller can close the stream). `null` = no such task. |
| 115 | */ |
| 116 | subscribe( |
| 117 | taskId: string, |
| 118 | sinceSeq: number, |
| 119 | onEvent: (e: TaskEvent) => void, |
| 120 | ): { unsubscribe: () => void; finished: boolean } | null { |
| 121 | const task = this.tasks.get(taskId); |
| 122 | if (!task) return null; |
| 123 | for (const ev of task.events) { |
| 124 | if (ev.seq > sinceSeq) onEvent(ev); |
| 125 | } |
| 126 | if (task.status !== 'running') { |
| 127 | return { unsubscribe: () => {}, finished: true }; |
| 128 | } |
| 129 | task.subscribers.add(onEvent); |
| 130 | return { |
| 131 | unsubscribe: () => { task.subscribers.delete(onEvent); }, |
| 132 | finished: false, |
| 133 | }; |
| 134 | } |
| 135 | |
| 136 | get(taskId: string): Task | undefined { |
| 137 | return this.tasks.get(taskId); |
| 138 | } |
| 139 | |
| 140 | private prune(): void { |
| 141 | const now = Date.now(); |
| 142 | for (const [id, t] of this.tasks) { |
| 143 | if (t.status !== 'running' && t.endedAt && now - t.endedAt > TaskRegistry.TTL_MS) { |
| 144 | this.tasks.delete(id); |
| 145 | } |
| 146 | } |
| 147 | } |
| 148 | } |
| 149 |