import { SQSClient, SQSClientConfig } from './clients/sqs';
import { MessageSource, MessageSink, Message } from './';
import { Logger } from './logger';
export interface SNSMessage extends Message {
    MessageId: string;
    TopicArn: string;
    Message: string;
    Timestamp: string;
    SignatureVersion: string;
    Signature: string;
    SigningCertURL: string;
    UnsubscribeURL: string;
}
export declare class SQSQueue<T extends Message> implements MessageSource<T>, MessageSink<T> {
    private sqsClient;
    private messageMeta;
    private readonly log;
    constructor(clientOrConfig: SQSClient | SQSClientConfig, log?: Logger);
    getNext(): Promise<T>;
    complete(message: T): Promise<void>;
    backoff(message: T): Promise<number>;
    delay(message: T, delaySecs: number): Promise<number>;
    persist(payload: T): Promise<void>;
    deleteQueue(): Promise<void>;
    initialize(): Promise<void>;
    isReady(): boolean;
}
export declare class MemoryQueue<T extends Message> implements MessageSource<T>, MessageSink<T> {
    private queue;
    private invisible;
    setInvisible(message: T, seconds?: number): void;
    isVisible(message: T): boolean;
    getNext(): Promise<T>;
    persist(payload: T): Promise<void>;
    complete(message: T): Promise<void>;
    backoff(_message: T): Promise<number>;
    delay(message: T, delaySecs: number): Promise<number>;
}