upload project

utils/image-cache-manager.js

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+/**
+ * 图片缓存管理器
+ * 实现头像和聊天图片的缓存功能
+ */
+
+class ImageCacheManager {
+  constructor() {
+    this.cache = new Map();
+    this.cacheExpiry = new Map();
+    this.maxCacheSize = 100; // 最大缓存数量
+    this.cacheExpiryTime = 7 * 24 * 60 * 60 * 1000; // 7天缓存过期时间
+    this.avatarCacheExpiryTime = 30 * 24 * 60 * 60 * 1000; // 头像30天缓存过期时间
+
+    // 初始化缓存
+    this.initCache();
+  }
+
+  /**
+   * 初始化缓存，从本地存储加载
+   */
+  initCache() {
+    try {
+      const cachedData = wx.getStorageSync('image_cache');
+      if (cachedData) {
+        const data = JSON.parse(cachedData);
+        this.cache = new Map(data.cache || []);
+        this.cacheExpiry = new Map(data.expiry || []);
+
+      }
+    } catch (error) {
+      console.error('❌ 初始化图片缓存失败:', error);
+    }
+  }
+
+  /**
+   * 保存缓存到本地存储
+   */
+  saveCache() {
+    try {
+      const data = {
+        cache: Array.from(this.cache.entries()),
+        expiry: Array.from(this.cacheExpiry.entries())
+      };
+      wx.setStorageSync('image_cache', JSON.stringify(data));
+    } catch (error) {
+      console.error('❌ 保存图片缓存失败:', error);
+    }
+  }
+
+  /**
+   * 清理过期缓存
+   */
+  cleanExpiredCache() {
+    const now = Date.now();
+    const expiredKeys = [];
+
+    for (const [key, expiryTime] of this.cacheExpiry.entries()) {
+      if (now > expiryTime) {
+        expiredKeys.push(key);
+      }
+    }
+
+    expiredKeys.forEach(key => {
+      this.cache.delete(key);
+      this.cacheExpiry.delete(key);
+    });
+
+    if (expiredKeys.length > 0) {
+
+      this.saveCache();
+    }
+  }
+
+  /**
+   * 清理超出最大数量的缓存
+   */
+  cleanExcessCache() {
+    if (this.cache.size <= this.maxCacheSize) return;
+
+    // 按过期时间排序，删除最旧的
+    const sortedEntries = Array.from(this.cacheExpiry.entries())
+      .sort((a, b) => a[1] - b[1]);
+
+    const excessCount = this.cache.size - this.maxCacheSize;
+    const keysToDelete = sortedEntries.slice(0, excessCount).map(([key]) => key);
+
+    keysToDelete.forEach(key => {
+      this.cache.delete(key);
+      this.cacheExpiry.delete(key);
+    });
+
+    this.saveCache();
+  }
+
+  /**
+   * 生成缓存键
+   */
+  generateCacheKey(url, type = 'image') {
+    return `${type}_${url}`;
+  }
+
+  /**
+   * 检查缓存是否存在且有效
+   */
+  isCached(url, type = 'image') {
+    const key = this.generateCacheKey(url, type);
+    const expiryTime = this.cacheExpiry.get(key);
+
+    if (!expiryTime) return false;
+
+    if (Date.now() > expiryTime) {
+      // 缓存已过期，删除
+      this.cache.delete(key);
+      this.cacheExpiry.delete(key);
+      return false;
+    }
+
+    return this.cache.has(key);
+  }
+
+  /**
+   * 获取缓存的图片路径
+   */
+  getCachedPath(url, type = 'image') {
+    const key = this.generateCacheKey(url, type);
+    return this.cache.get(key);
+  }
+
+  /**
+   * 缓存图片
+   */
+  async cacheImage(url, type = 'image') {
+    if (!url || url.startsWith('data:')) {
+
+      return url; // 不缓存base64等
+    }
+
+    // 对于本地路径前缀，直接返回
+    if (url.startsWith('/')) {
+
+      return url;
+    }
+
+    // 确保URL是完整的，添加https前缀如果缺少
+    let fullUrl = url;
+    if (!fullUrl.startsWith('http://') && !fullUrl.startsWith('https://')) {
+
+      fullUrl = 'https://' + url;
+    }
+
+    const key = this.generateCacheKey(fullUrl, type);
+
+    // 检查是否已缓存
+    if (this.isCached(fullUrl, type)) {
+
+      return this.getCachedPath(fullUrl, type);
+    }
+
+    try {
+
+      // 下载图片
+      const downloadResult = await new Promise((resolve, reject) => {
+        wx.downloadFile({
+          url: fullUrl,
+          timeout: 15000, // 增加超时时间
+          success: resolve,
+          fail: reject
+        });
+      });
+
+      if (downloadResult.statusCode === 200) {
+        const localPath = downloadResult.tempFilePath;
+
+        // 设置缓存过期时间
+        const expiryTime = type === 'avatar'
+          ? Date.now() + this.avatarCacheExpiryTime
+          : Date.now() + this.cacheExpiryTime;
+
+        // 保存到缓存
+        this.cache.set(key, localPath);
+        this.cacheExpiry.set(key, expiryTime);
+
+        // 清理过期和超量缓存
+        this.cleanExpiredCache();
+        this.cleanExcessCache();
+
+        return localPath;
+      } else {
+        console.warn('⚠️ 图片下载失败，状态码:', downloadResult.statusCode, 'URL:', fullUrl);
+        // 如果下载失败，返回完整的URL
+        return fullUrl;
+      }
+    } catch (error) {
+      console.error('❌ 缓存图片失败:', fullUrl, error);
+      // 在缓存失败时，返回完整的URL
+      return fullUrl;
+    }
+  }
+
+  /**
+   * 缓存头像
+   */
+  async cacheAvatar(url) {
+    return this.cacheImage(url, 'avatar');
+  }
+
+  /**
+   * 更新头像缓存（当头像URL变化时）
+   */
+  async updateAvatarCache(oldUrl, newUrl) {
+    if (oldUrl && oldUrl !== newUrl) {
+      const oldKey = this.generateCacheKey(oldUrl, 'avatar');
+      this.cache.delete(oldKey);
+      this.cacheExpiry.delete(oldKey);
+
+    }
+
+    if (newUrl) {
+      return await this.cacheAvatar(newUrl);
+    }
+
+    return newUrl;
+  }
+
+  /**
+   * 预加载图片（用于聊天中的图片）
+   */
+  async preloadImage(url) {
+    return this.cacheImage(url, 'chat_image');
+  }
+
+  /**
+   * 获取缓存统计信息
+   */
+  getCacheStats() {
+    const now = Date.now();
+    let avatarCount = 0;
+    let imageCount = 0;
+    let expiredCount = 0;
+
+    for (const [key, expiryTime] of this.cacheExpiry.entries()) {
+      if (key.startsWith('avatar_')) {
+        avatarCount++;
+      } else if (key.startsWith('image_') || key.startsWith('chat_image_')) {
+        imageCount++;
+      }
+
+      if (now > expiryTime) {
+        expiredCount++;
+      }
+    }
+
+    return {
+      total: this.cache.size,
+      avatar: avatarCount,
+      image: imageCount,
+      expired: expiredCount,
+      maxSize: this.maxCacheSize
+    };
+  }
+
+  /**
+   * 清空所有缓存
+   */
+  clearAllCache() {
+    this.cache.clear();
+    this.cacheExpiry.clear();
+    this.saveCache();
+
+  }
+
+  /**
+   * 清理指定类型的缓存
+   */
+  clearCacheByType(type) {
+    const keysToDelete = [];
+
+    for (const key of this.cache.keys()) {
+      if (key.startsWith(`${type}_`)) {
+        keysToDelete.push(key);
+      }
+    }
+
+    keysToDelete.forEach(key => {
+      this.cache.delete(key);
+      this.cacheExpiry.delete(key);
+    });
+
+    this.saveCache();
+  }
+}
+
+// 创建单例实例
+const imageCacheManager = new ImageCacheManager();
+
+module.exports = imageCacheManager;