fix: 修复并发计数器在请求异常时不能正确减少的问题

- 增强事件监听机制
  - 监听 req 的 close 和 aborted 事件
  - 监听 res 的 finish 和 error 事件
  - 使用标志位确保只减少一次计数

- 改进日志记录
  - 增加并发计数增减的详细日志
  - 记录请求关闭和中断事件

- 确保计数器安全性
  - 使用 Lua 脚本原子操作防止负数
  - 优化 Redis 操作逻辑

- 增强管理界面
  - API Keys 列表显示当前并发数
  - 并发数超过 0 时用橙色标记
  - 显示当前并发数/限制数格式

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

src/middleware/auth.js

@@ -65,6 +65,7 @@ const authenticateApiKey = async (req, res, next) => {
     const concurrencyLimit = validation.keyData.concurrencyLimit || 0;
     if (concurrencyLimit > 0) {
       const currentConcurrency = await redis.incrConcurrency(validation.keyData.id);
+      logger.api(`📈 Incremented concurrency for key: ${validation.keyData.id} (${validation.keyData.name}), current: ${currentConcurrency}, limit: ${concurrencyLimit}`);
       
       if (currentConcurrency > concurrencyLimit) {
         // 如果超过限制，立即减少计数
@@ -78,19 +79,38 @@ const authenticateApiKey = async (req, res, next) => {
         });
       }
       
-      // 在响应结束时减少并发计数
-      res.on('finish', () => {
-        redis.decrConcurrency(validation.keyData.id).catch(error => {
-          logger.error('Failed to decrement concurrency:', error);
+      // 使用标志位确保只减少一次
+      let concurrencyDecremented = false;
+      
+      const decrementConcurrency = async () => {
+        if (!concurrencyDecremented) {
+          concurrencyDecremented = true;
+          try {
+            const newCount = await redis.decrConcurrency(validation.keyData.id);
+            logger.api(`📉 Decremented concurrency for key: ${validation.keyData.id} (${validation.keyData.name}), new count: ${newCount}`);
+          } catch (error) {
+            logger.error(`Failed to decrement concurrency for key ${validation.keyData.id}:`, error);
+          }
+        }
+      };
+      
+      // 监听多个事件以确保在各种情况下都能正确减少计数
+      res.on('finish', decrementConcurrency);
+      res.on('error', decrementConcurrency);
+      req.on('close', () => {
+        logger.api(`🔌 Request closed for key: ${validation.keyData.id} (${validation.keyData.name})`);
+        decrementConcurrency();
       });
+      req.on('aborted', () => {
+        logger.api(`⚠️ Request aborted for key: ${validation.keyData.id} (${validation.keyData.name})`);
+        decrementConcurrency();
       });
       
-      // 在响应错误时也减少并发计数
-      res.on('error', () => {
-        redis.decrConcurrency(validation.keyData.id).catch(error => {
-          logger.error('Failed to decrement concurrency on error:', error);
-        });
-      });
+      // 存储并发信息到请求对象，便于后续处理
+      req.concurrencyInfo = {
+        apiKeyId: validation.keyData.id,
+        decrementConcurrency
+      };
     }
 
     // 将验证信息添加到请求对象（只包含必要信息）

src/models/redis.js

@@ -724,6 +724,7 @@ class RedisClient {
       // 设置过期时间为5分钟，防止计数器永远不清零
       await this.client.expire(key, 300);
       
+      logger.database(`🔢 Incremented concurrency for key ${apiKeyId}: ${count}`);
       return count;
     } catch (error) {
       logger.error('❌ Failed to increment concurrency:', error);
@@ -735,14 +736,28 @@ class RedisClient {
   async decrConcurrency(apiKeyId) {
     try {
       const key = `concurrency:${apiKeyId}`;
-      const count = await this.client.decr(key);
       
-      // 如果计数降到0或以下，删除键
-      if (count <= 0) {
-        await this.client.del(key);
-        return 0;
-      }
+      // 使用Lua脚本确保原子性操作，防止计数器变成负数
+      const luaScript = `
+        local key = KEYS[1]
+        local current = tonumber(redis.call('get', key) or "0")
         
+        if current <= 0 then
+          redis.call('del', key)
+          return 0
+        else
+          local new_value = redis.call('decr', key)
+          if new_value <= 0 then
+            redis.call('del', key)
+            return 0
+          else
+            return new_value
+          end
+        end
+      `;
+      
+      const count = await this.client.eval(luaScript, 1, key);
+      logger.database(`🔢 Decremented concurrency for key ${apiKeyId}: ${count}`);
       return count;
     } catch (error) {
       logger.error('❌ Failed to decrement concurrency:', error);

src/services/apiKeyService.js

@@ -132,12 +132,13 @@ class ApiKeyService {
     try {
       const apiKeys = await redis.getAllApiKeys();
       
-      // 为每个key添加使用统计
+      // 为每个key添加使用统计和当前并发数
       for (const key of apiKeys) {
         key.usage = await redis.getUsageStats(key.id);
         key.tokenLimit = parseInt(key.tokenLimit);
         key.requestLimit = parseInt(key.requestLimit);
         key.concurrencyLimit = parseInt(key.concurrencyLimit || 0);
+        key.currentConcurrency = await redis.getConcurrency(key.id);
         key.isActive = key.isActive === 'true';
         delete key.apiKey; // 不返回哈希后的key
       }

web/admin/index.html

@@ -430,6 +430,14 @@
                                                         <span class="text-gray-600">并发限制:</span>
                                                         <span class="font-medium text-purple-600">{{ key.concurrencyLimit > 0 ? key.concurrencyLimit : '无限制' }}</span>
                                                     </div>
+                                                    <!-- 当前并发数 -->
+                                                    <div class="flex justify-between text-sm">
+                                                        <span class="text-gray-600">当前并发:</span>
+                                                        <span :class="['font-medium', key.currentConcurrency > 0 ? 'text-orange-600' : 'text-gray-600']">
+                                                            {{ key.currentConcurrency || 0 }}
+                                                            <span v-if="key.concurrencyLimit > 0" class="text-xs text-gray-500">/ {{ key.concurrencyLimit }}</span>
+                                                        </span>
+                                                    </div>
                                                     <!-- 输入/输出Token -->
                                                     <div class="flex justify-between text-xs text-gray-500">
                                                         <span>输入: {{ formatNumber((key.usage && key.usage.total && key.usage.total.inputTokens) || 0) }}</span>