import { Level } from 'level';
interface DbUtilsOptions {
    valueEncoding?: string;
    maxCacheSize?: number;
    enableLogging?: boolean;
    failoverOptions?: any;
}
export default class DbUtils {
    db: Level<string, any>;
    private maxCacheSize;
    cacheDir: string;
    private failover;
    private logger;
    /**
     * @param cacheDir Database file path
     * @param options Optional parameters
     */
    constructor(cacheDir: string, options?: DbUtilsOptions);
    /**
     * Unified DB read operation handler
     */
    get(key: string, defaultValue?: any): Promise<any>;
    /**
     * Unified DB write operation handler
     */
    put(key: string, value: any): Promise<void>;
    /**
     * Unified DB delete operation handler
     */
    del(key: string): Promise<void>;
    /**
     * Calculate cache size
     */
    calculateCacheSize(): Promise<number>;
    /**
     * Provide iterator interface for reading all key-value pairs
     */
    iterator(): AsyncGenerator<[string, any], void, unknown>;
    /**
     * Clear database
     */
    clear(): Promise<void>;
    /**
     * Clean least accessed entries in cache
     */
    cleanLeastAccessedCache(): Promise<void>;
    /**
     * Clear all cache
     */
    clearAll(): Promise<void>;
    /**
     * Delete data stored in a paginated manner.
     */
    deletePaginated(keyBase: string): Promise<void>;
    /**
     * Unified DB token cache delete operation handler with pagination support
     */
    clearTokenCache(tokenId: string): Promise<void>;
    /**
     * 添加用于存储全局元数据的方法
     */
    updateGlobalMetadata(key: string, data: any): Promise<void>;
    /**
     * 添加用于获取全局元数据的方法
     */
    getGlobalMetadata(key: string, defaultValue?: any): Promise<any>;
}
export {};