152 lines
3.3 KiB
TypeScript
152 lines
3.3 KiB
TypeScript
import { logger } from "../utils/logger";
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export interface CacheOptions {
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ttl?: number; // 生存时间（毫秒）
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maxSize?: number; // 最大缓存项数
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}
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export interface CacheEntry<T> {
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value: T;
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timestamp: number;
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ttl: number;
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}
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class Cache {
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private cache = new Map<string, CacheEntry<unknown>>();
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private maxSize: number;
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private defaultTtl: number;
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constructor(options: CacheOptions = {}) {
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this.maxSize = options.maxSize || 1000;
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this.defaultTtl = options.ttl || 5 * 60 * 1000; // 默认5分钟
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}
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set<T>(key: string, value: T, ttl?: number): void {
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// 如果缓存已满，删除最旧的项
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if (this.cache.size >= this.maxSize) {
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this.evictOldest();
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}
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const entry: CacheEntry<T> = {
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value,
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timestamp: Date.now(),
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ttl: ttl || this.defaultTtl,
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};
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this.cache.set(key, entry);
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logger.debug("Cache set", { key, ttl: entry.ttl });
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}
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get<T>(key: string): T | null {
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const entry = this.cache.get(key) as CacheEntry<T> | undefined;
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if (!entry) {
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logger.debug("Cache miss", { key });
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return null;
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}
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// 检查是否过期
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if (Date.now() - entry.timestamp > entry.ttl) {
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this.cache.delete(key);
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logger.debug("Cache expired", { key });
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return null;
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}
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logger.debug("Cache hit", { key });
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return entry.value;
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}
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has(key: string): boolean {
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const entry = this.cache.get(key);
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if (!entry) return false;
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// 检查是否过期
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if (Date.now() - entry.timestamp > entry.ttl) {
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this.cache.delete(key);
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return false;
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}
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return true;
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}
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delete(key: string): boolean {
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const deleted = this.cache.delete(key);
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if (deleted) {
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logger.debug("Cache deleted", { key });
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}
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return deleted;
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}
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clear(): void {
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this.cache.clear();
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logger.info("Cache cleared");
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}
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size(): number {
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return this.cache.size;
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}
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private evictOldest(): void {
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let oldestKey: string | null = null;
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let oldestTime = Date.now();
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for (const [key, entry] of this.cache.entries()) {
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if (entry.timestamp < oldestTime) {
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oldestTime = entry.timestamp;
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oldestKey = key;
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}
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}
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if (oldestKey) {
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this.cache.delete(oldestKey);
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logger.debug("Cache evicted oldest", { key: oldestKey });
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}
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}
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// 清理过期项
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cleanup(): void {
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const now = Date.now();
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let cleanedCount = 0;
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for (const [key, entry] of this.cache.entries()) {
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if (now - entry.timestamp > entry.ttl) {
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this.cache.delete(key);
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cleanedCount++;
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}
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}
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if (cleanedCount > 0) {
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logger.info("Cache cleanup completed", { cleanedCount });
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}
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}
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// 获取缓存统计信息
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getStats(): {
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size: number;
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maxSize: number;
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hitRate: number;
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missRate: number;
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} {
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return {
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size: this.cache.size,
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maxSize: this.maxSize,
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hitRate: 0, // 需要实现命中率统计
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missRate: 0, // 需要实现未命中率统计
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};
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}
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}
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// 创建全局缓存实例
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export const cache = new Cache({
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maxSize: 1000,
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ttl: 5 * 60 * 1000, // 5分钟
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});
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// 定期清理过期项
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if (typeof window === "undefined") {
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// 仅在服务器端运行
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setInterval(() => {
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cache.cleanup();
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}, 60 * 1000); // 每分钟清理一次
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}
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