import { ReactiveControllerHost } from 'lit';
import { Logger } from '../logger';
export interface RequestQueueOptions {
    /**
     * Provide a name for debugging purposes.
     */
    name?: string;
    /**
     * Provide the owner of this queue for debugging purposes.
     */
    owner?: any;
}
export declare class RequestQueue {
    protected readonly _options: RequestQueueOptions;
    protected readonly _logger?: Logger;
    protected readonly _requestQueue: Map<string | symbol, () => void | Promise<void>>;
    protected _pendingFlush: import("../../utils/promise").DeferredPromise<unknown, unknown>;
    get name(): string | undefined;
    constructor(_host?: ReactiveControllerHost, _options?: RequestQueueOptions);
    /**
     * Whether callbacks should be called immediately or queued and flushed at a later time.
     */
    serveImmediately: boolean;
    /**
     * The number of callbacks that are currently in queue.
     */
    get size(): number;
    /**
     * Returns a clone of the current request queue.
     */
    cloneQueue(): Map<string | symbol, () => void | Promise<void>>;
    /**
     * Waits for the queue to be flushed.
     */
    waitForFlush(): Promise<void>;
    queue(key: string | symbol, callback: () => void | Promise<void>): Promise<void>;
    serve(key: string | symbol): Promise<void>;
    flush(): Promise<void>;
    protected _flush(): void;
    reset(): void;
    destroy(): void;
}