/**
 * Base Storage Adapter
 *
 * Abstract base class for storage adapters.
 * Provides common validation and default implementations.
 */
import type { StorageAdapter, SetOptions, SetEntry, MessageHandler, Unsubscribe } from '../types';
/**
 * Abstract base class for storage adapters.
 * Subclasses must implement the abstract methods.
 */
export declare abstract class BaseStorageAdapter implements StorageAdapter {
    /**
     * Backend name for error messages (e.g., 'memory', 'redis').
     */
    protected abstract readonly backendName: string;
    /**
     * Whether the adapter is currently connected.
     */
    protected connected: boolean;
    abstract connect(): Promise<void>;
    abstract disconnect(): Promise<void>;
    abstract ping(): Promise<boolean>;
    /**
     * Ensure adapter is connected before operations.
     * @throws StorageNotConnectedError if not connected
     */
    protected ensureConnected(): void;
    abstract get(key: string): Promise<string | null>;
    /**
     * Set with validation.
     */
    set(key: string, value: string, options?: SetOptions): Promise<void>;
    /**
     * Internal set implementation. Override in subclass.
     */
    protected abstract doSet(key: string, value: string, options?: SetOptions): Promise<void>;
    abstract delete(key: string): Promise<boolean>;
    abstract exists(key: string): Promise<boolean>;
    /**
     * Default mget: sequential gets.
     * Override for more efficient implementations.
     */
    mget(keys: string[]): Promise<(string | null)[]>;
    /**
     * Default mset: sequential sets.
     * Override for atomic/pipelined implementations.
     */
    mset(entries: SetEntry[]): Promise<void>;
    /**
     * Default mdelete: sequential deletes.
     * Override for more efficient implementations.
     */
    mdelete(keys: string[]): Promise<number>;
    abstract expire(key: string, ttlSeconds: number): Promise<boolean>;
    abstract ttl(key: string): Promise<number | null>;
    abstract keys(pattern?: string): Promise<string[]>;
    /**
     * Default count: keys().length.
     * Override for more efficient implementations.
     */
    count(pattern?: string): Promise<number>;
    abstract incr(key: string): Promise<number>;
    abstract decr(key: string): Promise<number>;
    abstract incrBy(key: string, amount: number): Promise<number>;
    /**
     * Default: pub/sub not supported.
     * Override in adapters that support it.
     */
    supportsPubSub(): boolean;
    /**
     * Default: throw not supported error.
     * Override in adapters that support pub/sub.
     */
    publish(_channel: string, _message: string): Promise<number>;
    /**
     * Default: throw not supported error.
     * Override in adapters that support pub/sub.
     */
    subscribe(_channel: string, _handler: MessageHandler): Promise<Unsubscribe>;
    /**
     * Get suggestion message for pub/sub not supported error.
     * Override in specific adapters.
     */
    protected getPubSubSuggestion(): string;
    /**
     * Validate set options.
     */
    protected validateSetOptions(options?: SetOptions): void;
}