/**
 * Simple async serial task executor.
 * Tasks within a partition are processed one at a time, in order.
 * Replaces RxQueue + createRxQueue (~200 lines) with ~40 lines.
 */
export declare class PartitionWorker {
    readonly id: string | number;
    private queue;
    private running;
    private _paused;
    private _destroyed;
    constructor(id: string | number);
    /**
     * Enqueue a task and return a promise that resolves when the task completes.
     * Tasks are processed in FIFO order, one at a time.
     */
    enqueue<T>(fn: () => Promise<T>): Promise<T>;
    pause(): void;
    resume(): void;
    /**
     * Returns a promise that resolves when all currently queued tasks are done.
     */
    drain(): Promise<void>;
    destroy(): void;
    get pending(): number;
    private pump;
}