import { OnModuleDestroy } from '@nestjs/common';
import { BaseCacheProvider } from './base-cache.provider';
/**
 * LRU Memory Cache Provider
 *
 * High-performance in-memory LRU (Least Recently Used) cache provider.
 * This is an L2 cache layer with fast access and automatic eviction.
 *
 * Features:
 * - O(1) get/set operations
 * - Automatic LRU eviction when cache is full
 * - Optional TTL (Time To Live) support
 * - Namespace isolation
 * - Cache statistics (size, hit rate, usage percentage)
 *
 * Use Cases:
 * - Session data caching
 * - Frequently accessed configuration
 * - API response caching
 * - Temporary data storage
 *
 * @example
 * ```typescript
 * const provider = new LRUCacheProvider({
 *   maxSize: 1000,
 *   ttl: 60000, // optional TTL
 *   namespace: 'my-cache',
 * });
 * ```
 */
export declare class LRUCacheProvider extends BaseCacheProvider implements OnModuleDestroy {
    private readonly logger;
    private cache;
    private namespace;
    private defaultTtl?;
    constructor(options?: {
        maxSize?: number;
        ttl?: number;
        namespace?: string;
    });
    getName(): string;
    get<T>(key: string): Promise<T | null>;
    set<T>(key: string, value: T, ttl?: number): Promise<void>;
    delete(key: string | string[]): Promise<void>;
    deletePattern(pattern: string): Promise<number>;
    clear(): Promise<void>;
    has(key: string): Promise<boolean>;
    mget<T>(keys: string[]): Promise<(T | null)[]>;
    mset(items: Array<{
        key: string;
        value: any;
    }>, ttl?: number): Promise<void>;
    /**
     * Get cache size
     */
    getSize(): number;
    /**
     * Get cache statistics
     */
    getStats(): {
        provider: string;
        namespace: string;
        size: any;
        maxSize: any;
        calculatedSize: any;
        usagePercentage: number;
    };
    /**
     * Clean up expired items
     */
    cleanup(): number;
    /**
     * Destroy the provider
     */
    onModuleDestroy(): void;
    private getFullKey;
}