/// <reference types="node" />
/// <reference types="node" />
import { Duplex, DuplexOptions } from 'stream';
import type { BSONSerializeOptions, Document } from '../bson';
import type { ClientSession } from '../sessions';
import { BufferPool, Callback } from '../utils';
import { WriteProtocolMessageType } from './commands';
import { CompressorName } from './wire_protocol/compression';
/** @internal */
declare const kBuffer: unique symbol;
/** @internal */
export interface MessageStreamOptions extends DuplexOptions {
    maxBsonMessageSize?: number;
}
/** @internal */
export interface OperationDescription extends BSONSerializeOptions {
    started: number;
    cb: Callback<Document>;
    command: boolean;
    documentsReturnedIn?: string;
    fullResult: boolean;
    noResponse: boolean;
    raw: boolean;
    requestId: number;
    session?: ClientSession;
    socketTimeoutOverride?: boolean;
    agreedCompressor?: CompressorName;
    zlibCompressionLevel?: number;
    $clusterTime?: Document;
}
/**
 * A duplex stream that is capable of reading and writing raw wire protocol messages, with
 * support for optional compression
 * @internal
 */
export declare class MessageStream extends Duplex {
    /** @internal */
    maxBsonMessageSize: number;
    /** @internal */
    [kBuffer]: BufferPool;
    /** @internal */
    isMonitoringConnection: boolean;
    constructor(options?: MessageStreamOptions);
    get buffer(): BufferPool;
    _write(chunk: Buffer, _: unknown, callback: Callback<Buffer>): void;
    _read(): void;
    writeCommand(command: WriteProtocolMessageType, operationDescription: OperationDescription): void;
}
export {};
//# sourceMappingURL=message_stream.d.ts.map