| export function createLatestWorkerQueue<T extends { key: string }>(input: { |
| run: (request: T) => Promise<void> |
| supersede: (request: T) => void |
| dispose: (key: string) => void |
| }) { |
| type Slot = { type: "highlight"; key: string; request?: T } |
| const jobs: Array<Slot | { type: "dispose"; key: string }> = [] |
| const slots = new Map<string, Slot>() |
| let running: Promise<void> | undefined |
| let cursor = 0 |
|
|
| const schedule = () => { |
| if (running) return |
| running = Promise.resolve() |
| .then(async () => { |
| while (cursor < jobs.length) { |
| const job = jobs[cursor++]! |
| if (job.type === "dispose") { |
| input.dispose(job.key) |
| continue |
| } |
| if (slots.get(job.key) === job) slots.delete(job.key) |
| const request = job.request |
| job.request = undefined |
| if (request) await input.run(request) |
| } |
| }) |
| .finally(() => { |
| jobs.splice(0, cursor) |
| cursor = 0 |
| running = undefined |
| if (jobs.length > 0) schedule() |
| }) |
| } |
|
|
| return { |
| highlight(request: T) { |
| const slot = slots.get(request.key) |
| if (slot) { |
| if (slot.request) input.supersede(slot.request) |
| slot.request = request |
| return |
| } |
| const next: Slot = { type: "highlight", key: request.key, request } |
| slots.set(request.key, next) |
| jobs.push(next) |
| schedule() |
| }, |
| dispose(key: string) { |
| const slot = slots.get(key) |
| if (slot?.request) input.supersede(slot.request) |
| if (slot) { |
| slot.request = undefined |
| slots.delete(key) |
| } |
| jobs.push({ type: "dispose", key }) |
| schedule() |
| }, |
| pending: () => slots.size, |
| async idle() { |
| while (running) await running |
| }, |
| } |
| } |
|
|
