地址路径修改

miniprogram/utils/avatarCache.ts

@@ -0,0 +1,209 @@
+/**
+ * 头像缓存管理工具类
+ * 实现头像图片的KV存储和缓存机制，避免重复下载相同图片
+ */
+
+class AvatarCache {
+  private static instance: AvatarCache;
+  private cache: Map<string, string> = new Map(); // KV存储：avatarUrl -> 本地图片路径
+  private downloadingUrls: Set<string> = new Set(); // 正在下载的URL集合
+
+  private constructor() {}
+
+  public static getInstance(): AvatarCache {
+    if (!AvatarCache.instance) {
+      AvatarCache.instance = new AvatarCache();
+    }
+    return AvatarCache.instance;
+  }
+
+  /**
+   * 获取头像图片路径
+   * @param avatarUrl 头像URL
+   * @returns 本地图片路径或Promise<string>
+   */
+  public async getAvatarPath(avatarUrl: string): Promise<string> {
+    if (!avatarUrl) {
+      return this.getDefaultAvatarPath();
+    }
+
+    // 如果缓存中已存在，直接返回
+    if (this.cache.has(avatarUrl)) {
+      return this.cache.get(avatarUrl)!;
+    }
+
+    // 如果正在下载中，等待下载完成
+    if (this.downloadingUrls.has(avatarUrl)) {
+      return await this.waitForDownload(avatarUrl);
+    }
+
+    // 开始下载图片
+    return await this.downloadAndCacheAvatar(avatarUrl);
+  }
+
+  /**
+   * 获取头像URL（用于存储和传递，不下载图片）
+   * @param userId 用户ID
+   * @param avatarUrl 头像URL
+   * @returns 头像URL
+   */
+  public getAvatarUrl(avatarUrl: string): string {
+    if (!avatarUrl) {
+      return '/images/user-avatar.png';
+    }
+
+    // 如果缓存中已存在，直接返回URL（不下载）
+    if (this.cache.has(avatarUrl)) {
+      return avatarUrl;
+    }
+
+    // 如果不在缓存中，异步下载但不等待结果
+    if (!this.downloadingUrls.has(avatarUrl)) {
+      this.downloadAndCacheAvatar(avatarUrl).catch(() => {
+        // 下载失败不影响主流程
+      });
+    }
+
+    return avatarUrl;
+  }
+
+  /**
+   * 下载并缓存头像图片
+   * @param avatarUrl 头像URL
+   * @returns 本地图片路径
+   */
+  private async downloadAndCacheAvatar(avatarUrl: string): Promise<string> {
+    this.downloadingUrls.add(avatarUrl);
+
+    try {
+      // 下载图片到临时文件
+      const tempFilePath = await this.downloadImage(avatarUrl);
+      
+      // 缓存到KV存储
+      this.cache.set(avatarUrl, tempFilePath);
+      
+      return tempFilePath;
+    } catch (error) {
+      console.error(`下载头像失败: ${avatarUrl}`, error);
+      return this.getDefaultAvatarPath();
+    } finally {
+      this.downloadingUrls.delete(avatarUrl);
+    }
+  }
+
+  /**
+   * 下载图片到本地临时文件
+   * @param avatarUrl 头像URL
+   * @returns 本地临时文件路径
+   */
+  private async downloadImage(avatarUrl: string): Promise<string> {
+    return new Promise((resolve, reject) => {
+      wx.downloadFile({
+        url: avatarUrl,
+        success: (res) => {
+          if (res.statusCode === 200) {
+            resolve(res.tempFilePath);
+          } else {
+            reject(new Error(`下载失败，状态码: ${res.statusCode}`));
+          }
+        },
+        fail: (error) => {
+          reject(error);
+        }
+      });
+    });
+  }
+
+  /**
+   * 等待下载完成
+   * @param avatarUrl 头像URL
+   * @returns 本地图片路径
+   */
+  private async waitForDownload(avatarUrl: string): Promise<string> {
+    return new Promise((resolve) => {
+      const checkInterval = setInterval(() => {
+        if (!this.downloadingUrls.has(avatarUrl) && this.cache.has(avatarUrl)) {
+          clearInterval(checkInterval);
+          resolve(this.cache.get(avatarUrl)!);
+        }
+      }, 100);
+
+      // 设置超时时间
+      setTimeout(() => {
+        clearInterval(checkInterval);
+        resolve(this.getDefaultAvatarPath());
+      }, 5000);
+    });
+  }
+
+  /**
+   * 获取默认头像路径
+   * @returns 默认头像路径
+   */
+  private getDefaultAvatarPath(): string {
+    return '/images/user-avatar.png';
+  }
+
+  /**
+   * 预加载多个头像
+   * @param avatarUrls 头像URL数组
+   */
+  public async preloadAvatars(avatarUrls: string[]): Promise<void> {
+    const uniqueUrls = [...new Set(avatarUrls)];
+    
+    for (const url of uniqueUrls) {
+      if (url && !this.cache.has(url) && !this.downloadingUrls.has(url)) {
+        // 异步预加载，不等待结果
+        this.downloadAndCacheAvatar(url).catch(() => {
+          // 预加载失败不影响主流程
+        });
+      }
+    }
+  }
+
+  /**
+   * 预加载多个头像并等待所有加载完成
+   * @param avatarUrls 头像URL数组
+   */
+  public async preloadAvatarsAndWait(avatarUrls: string[]): Promise<void> {
+    const uniqueUrls = [...new Set(avatarUrls)];
+    const downloadPromises: Promise<string>[] = [];
+    
+    for (const url of uniqueUrls) {
+      if (url && !this.cache.has(url) && !this.downloadingUrls.has(url)) {
+        // 同步预加载，等待结果
+        downloadPromises.push(this.downloadAndCacheAvatar(url));
+      }
+    }
+    
+    if (downloadPromises.length > 0) {
+      console.log(`🔄 [AvatarCache] 开始预加载 ${downloadPromises.length} 个头像`);
+      await Promise.allSettled(downloadPromises);
+      console.log(`✅ [AvatarCache] 头像预加载完成，缓存大小: ${this.cache.size}`);
+    } else {
+      console.log('ℹ️ [AvatarCache] 没有需要预加载的头像');
+    }
+  }
+
+  /**
+   * 清除缓存
+   */
+  public clearCache(): void {
+    this.cache.clear();
+  }
+
+  /**
+   * 获取缓存统计信息
+   */
+  public getCacheStats(): { size: number; downloading: number } {
+    return {
+      size: this.cache.size,
+      downloading: this.downloadingUrls.size
+    };
+  }
+}
+
+// 导出单例实例
+export const avatarCache = AvatarCache.getInstance();
+
+export default AvatarCache;