/// <reference types="node" />
import { Readable } from 'stream';
import { CommonLogger } from '@naturalcycles/js-lib';
import { AbortableTransform } from '../../index';
import { TransformOptions, TransformTyped } from '../stream.model';
export interface TransformLimitOptions extends TransformOptions {
    /**
     * Nullish value (e.g 0 or undefined) would mean "no limit"
     */
    limit?: number;
    /**
     * If provided (recommended!) - it will call readable.destroy() on limit.
     * Without it - it will only stop the downstream consumers, but won't stop
     * the Readable ("source" of the stream).
     * It is almost always crucial to stop the Source too, so, please provide the Readable here!
     */
    sourceReadable?: Readable;
    /**
     * Please provide it (a Promise that resolves when the Stream is done, e.g finished consuming things)
     * to be able to wait for Consumers before calling `readable.destroy`.
     * Has no effect if `readable` is not provided.
     */
    streamDone?: Promise<void>;
    logger?: CommonLogger;
    /**
     * Set to true to enable additional debug messages, e.g it'll log
     * when readable still emits values after the limit is reached.
     */
    debug?: boolean;
}
/**
 * Class only exists to be able to do `instanceof TransformLimit`
 * and to set sourceReadable+streamDone to it in `_pipeline`.
 */
export declare class TransformLimit extends AbortableTransform {
}
/**
 * 0 or falsy value means "no limit"
 */
export declare function transformLimit<IN>(opt?: TransformLimitOptions): TransformTyped<IN, IN>;