import { Readable } from "stream";
export declare abstract class S3Service {
    private readonly bucket;
    private readonly region;
    private readonly s3;
    constructor(bucket: string, region: string);
    uploadObject(key: string, file: Buffer | Uint8Array | Readable, options?: Record<string, any>): Promise<string>;
    deleteObject(key: string): Promise<boolean>;
    getObject(key: string): Promise<Buffer>;
    getSignedUrl(key: string, expiresIn?: number): Promise<string>;
}