/**
 * Storage Middleware - Cross-cutting concerns for NoSQL storage operations
 * Handles caching, compression, monitoring, and security
 */
import { StorageResult, PerformanceMetrics } from '../interfaces/storage-engine';
export interface StorageMiddlewareConfig {
    enableCaching: boolean;
    enableCompression: boolean;
    enableMetrics: boolean;
    enableSecurity: boolean;
    enableRateLimiting: boolean;
    cacheConfig: {
        ttl: number;
        maxSize: number;
        strategy: 'lru' | 'lfu' | 'ttl';
    };
    compressionConfig: {
        threshold: number;
        algorithm: 'gzip' | 'brotli' | 'zstd';
        level: number;
    };
    rateLimitConfig: {
        maxRequests: number;
        windowMs: number;
        skipSuccessful: boolean;
    };
}
export interface MiddlewareContext {
    operation: string;
    collection?: string;
    startTime: number;
    metadata: Record<string, any>;
    userId?: string;
    requestId: string;
}
export type MiddlewareHandler<T> = (context: MiddlewareContext, next: () => Promise<StorageResult<T>>) => Promise<StorageResult<T>>;
/**
 * Storage Middleware Pipeline
 */
export declare class StorageMiddleware {
    private config;
    private cache;
    private metrics;
    private rateLimitCounters;
    constructor(config: StorageMiddlewareConfig);
    /**
     * Execute operation through middleware pipeline
     */
    execute<T>(context: MiddlewareContext, operation: () => Promise<StorageResult<T>>): Promise<StorageResult<T>>;
    /**
     * Rate limiting middleware
     */
    private rateLimitMiddleware;
    /**
     * Security middleware
     */
    private securityMiddleware;
    /**
     * Caching middleware
     */
    private cachingMiddleware;
    /**
     * Compression middleware
     */
    private compressionMiddleware;
    /**
     * Metrics middleware
     */
    private metricsMiddleware;
    /**
     * Get current metrics
     */
    getMetrics(operation?: string): PerformanceMetrics | Map<string, PerformanceMetrics>;
    /**
     * Clear cache
     */
    clearCache(pattern?: string): void;
    /**
     * Get cache statistics
     */
    getCacheStats(): {
        size: number;
        hitRate: number;
        totalHits: number;
        totalRequests: number;
    };
    private executeHandlers;
    private validateInput;
    private sanitizeOutput;
    private isReadOperation;
    private generateCacheKey;
    private getFromCache;
    private setCache;
    private evictCache;
    private invalidateCache;
    private shouldCompress;
    private compressData;
    private recordMetrics;
    private createDefaultMetrics;
    private startCleanupTasks;
}
/**
 * Default middleware configuration
 */
export declare function createDefaultMiddlewareConfig(): StorageMiddlewareConfig;
/**
 * Production-optimized middleware configuration
 */
export declare function createProductionMiddlewareConfig(): StorageMiddlewareConfig;
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