feat(server): 添加高并发优化配置支持

- ServerConfig 新增 Concurrency/ReadBufferSize/WriteBufferSize/ReduceMemoryUsage 配置
- defaults.go 设置默认值：256K 并发连接、16KB 缓冲区
- server.go 在 singleMode 和 vhostMode 中应用配置

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/config/config.go

@@ -199,6 +199,12 @@ type ServerConfig struct {
 	MaxConnsPerIP      int                  `yaml:"max_conns_per_ip"`
 	IdleTimeout        time.Duration        `yaml:"idle_timeout"`
 	WriteTimeout       time.Duration        `yaml:"write_timeout"`
+
+	// 高并发优化配置（可选，未配置时使用默认值）
+	Concurrency        int  `yaml:"concurrency"`         // 最大并发连接数（默认 256 * 1024）
+	ReadBufferSize     int  `yaml:"read_buffer_size"`    // 读缓冲区大小（字节，默认 16KB）
+	WriteBufferSize    int  `yaml:"write_buffer_size"`   // 写缓冲区大小（字节，默认 16KB）
+	ReduceMemoryUsage  bool `yaml:"reduce_memory_usage"` // 是否优先减少内存使用（默认 false，优先性能）
 }
 
 // StaticConfig 静态文件服务配置。

internal/config/defaults.go

@@ -45,6 +45,11 @@ func DefaultConfig() *Config {
 			IdleTimeout:        120 * time.Second,
 			MaxConnsPerIP:      1000,
 			MaxRequestsPerConn: 10000,
+			// 高并发优化配置默认值
+			Concurrency:        256 * 1024, // 256K 最大并发连接
+			ReadBufferSize:     16 * 1024,  // 16KB 读缓冲
+			WriteBufferSize:    16 * 1024,  // 16KB 写缓冲
+			ReduceMemoryUsage:  false,      // 优先性能
 			CacheAPI: &CacheAPIConfig{
 				Enabled: false,
 				Path:    "/_cache/purge",
@@ -255,6 +260,11 @@ func GenerateConfigYAML(cfg *Config) ([]byte, error) {
 	fmt.Fprintf(&buf, "    max_conns_per_ip: %d         # 每 IP 最大连接数（0 表示不限制）\n", cfg.Servers[0].MaxConnsPerIP)
 	fmt.Fprintf(&buf, "    max_requests_per_conn: %d    # 每连接最大请求数（0 表示不限制）\n", cfg.Servers[0].MaxRequestsPerConn)
 	fmt.Fprintf(&buf, "    client_max_body_size: \"1MB\"  # 请求体大小限制（支持单位: b, kb, mb, gb）\n")
+	buf.WriteString("    # 高并发优化配置（可选，未配置时使用默认值）\n")
+	fmt.Fprintf(&buf, "    # concurrency: %d           # 最大并发连接数（默认 %d）\n", cfg.Servers[0].Concurrency, cfg.Servers[0].Concurrency)
+	fmt.Fprintf(&buf, "    # read_buffer_size: %d       # 读缓冲区大小（字节，默认 %d）\n", cfg.Servers[0].ReadBufferSize, cfg.Servers[0].ReadBufferSize)
+	fmt.Fprintf(&buf, "    # write_buffer_size: %d      # 写缓冲区大小（字节，默认 %d）\n", cfg.Servers[0].WriteBufferSize, cfg.Servers[0].WriteBufferSize)
+	fmt.Fprintf(&buf, "    # reduce_memory_usage: %v    # 是否优先减少内存使用（默认 %v）\n", cfg.Servers[0].ReduceMemoryUsage, cfg.Servers[0].ReduceMemoryUsage)
 	buf.WriteString("\n")
 
 	// cache_api 配置

internal/server/server.go

@@ -512,6 +512,11 @@ func (s *Server) startSingleMode() error {
 		MaxConnsPerIP:      serverCfg.MaxConnsPerIP,
 		MaxRequestsPerConn: serverCfg.MaxRequestsPerConn,
 		CloseOnShutdown:    true,
+		// 高并发优化配置
+		Concurrency:        serverCfg.Concurrency,
+		ReadBufferSize:     serverCfg.ReadBufferSize,
+		WriteBufferSize:    serverCfg.WriteBufferSize,
+		ReduceMemoryUsage:  serverCfg.ReduceMemoryUsage,
 	}
 
 	s.running = true
@@ -632,6 +637,11 @@ func (s *Server) startVHostMode() error {
 		MaxConnsPerIP:      serverCfg.MaxConnsPerIP,
 		MaxRequestsPerConn: serverCfg.MaxRequestsPerConn,
 		CloseOnShutdown:    true,
+		// 高并发优化配置
+		Concurrency:        serverCfg.Concurrency,
+		ReadBufferSize:     serverCfg.ReadBufferSize,
+		WriteBufferSize:    serverCfg.WriteBufferSize,
+		ReduceMemoryUsage:  serverCfg.ReduceMemoryUsage,
 	}
 
 	s.running = true