import { Logger } from './logger';
import { Message, MessageSource, MessageSink, MessageTransformer } from './source_sink_task';
export interface SourceSinkRunnerConfig<T extends Message, R extends Message> {
    source: MessageSource<T>;
    transformer?: MessageTransformer<T, R>;
    sink?: MessageSink<R>;
    logger?: Logger;
    delayMs?: number;
    errorHandler?: (error: Error, log: Logger, attemptCount: number, message: Message) => void;
}
/**
 * SourceSinkRunner polls the message source and sends to the message sink after running a transform on the message.
 * Note: With the source sink runner, the source is responsible for not sending duplicate messages.
 */
export declare class SourceSinkRunner<T extends Message, R extends Message> {
    private config;
    private runningTask;
    private running;
    private log;
    constructor(config: SourceSinkRunnerConfig<T, R>);
    run(): void;
    runOnce(): Promise<void>;
    private processMessage;
    stop(): Promise<void>;
}