/**
 * When buffered realtime work runs.
 *
 * `'frame'` coalesces a burst of events into one cache write per animation
 * frame. `'sync'` restores the older behaviour of writing as each event
 * arrives. A number debounces by that many milliseconds.
 */
export type NotifyScheduler = 'sync' | 'frame' | number;
/** The timer functions the scheduler needs, injectable so tests control time. */
export type RealtimeClock = {
    setTimeout: (fn: () => void, ms: number) => unknown;
    clearTimeout: (handle: unknown) => void;
};
export type FlushScheduler = {
    /**
     * Ask for `flush` to run. Calls made while a flush is already pending are
     * absorbed into it, so the flush runs once per window however many events
     * arrived.
     */
    schedule: (flush: () => void) => void;
    /** Drop a pending flush without running it. */
    cancel: () => void;
};
export declare const systemClock: RealtimeClock;
export declare function createFlushScheduler(mode: NotifyScheduler, clock?: RealtimeClock): FlushScheduler;
//# sourceMappingURL=realtime-flush.d.ts.map