declare const QUERIES: {
    readonly AddQueue: "insert into queue (id, created, job, return_address) values (@id, @created, @job, @return_address)";
    readonly DeleteQueue: "delete from queue where id = @id";
    readonly GetNextBatch: "select * from queue where id > @cursor order by id limit @count";
    readonly GetQueueCount: "select count(*) as count from queue";
    readonly GetLastQueue: "select * from queue order by id desc limit 1";
    readonly AddTimer: "insert into timer (expires, id, created, job) values (@expires, @id, @created, @job)";
    readonly DeleteTimer: "delete from timer where expires = @expires and id = @id";
    readonly GetNextTimer: "select * from timer order by expires limit 1";
    readonly GetTimerCount: "select count(*) as count from timer";
};
export type QueryKey = keyof typeof QUERIES;
interface QueueItem {
    id: number;
    created: number;
    job: string;
    return_address?: string;
}
interface Timer {
    expires: number;
    id: string;
    created: number;
    job: string;
}
export declare class Database {
    private db;
    private statements;
    constructor(filename: string);
    close(): void;
    vacuum(): void;
    addQueue(id: number, created: number, job: string, returnAddress?: string): void;
    deleteQueue(id: number): boolean;
    getNextBatch(cursor: number, count: number): QueueItem[];
    getQueueCount(): number;
    getLastQueue(): QueueItem | undefined;
    addTimer(expires: number, id: string, created: number, job: string): void;
    deleteTimer(expires: number, id: string): void;
    getNextTimer(): Timer | undefined;
    getTimerCount(): number;
}
export {};