export declare const DEFAULT_MAX_PENDING_INPUT_BYTES: number;
export declare const DEFAULT_MAX_PENDING_OUTPUT_BYTES: number;
export declare const DEFAULT_BACKPRESSURE_TIMEOUT_MS = 30000;
export declare const MAX_CONTROL_FRAME_BYTES: number;
export declare const MAX_BUFFER_LIMIT_BYTES: number;
export interface RestorableReadable {
    readonly readableFlowing?: boolean | null;
    pause(): unknown;
    resume(): unknown;
}
export interface PausableSocket {
    pause?: () => void;
    resume?: () => void;
}
export declare class BoundedBufferQueue {
    private readonly limitBytes;
    private readonly chunks;
    private bytes;
    constructor(limitBytes: number);
    get length(): number;
    get byteLength(): number;
    peek(): Buffer | undefined;
    enqueue(chunk: Buffer): boolean;
    shift(): Buffer | undefined;
    clear(): void;
}
export declare function validateByteLimit(value: number, label: string): number;
export declare function validateTimeoutLimit(value: number, label?: string): number;
export declare function pauseSocket(socket: PausableSocket): void;
export declare function resumeSocket(socket: PausableSocket): void;
export declare function restoreReadableState(input: RestorableReadable, flowing: boolean | null | undefined, wasPaused: boolean): void;