// 高性能HTTP服務(wù)器配置
func main() {
    r := gin.New()
    r.Use(gin.Recovery())
    
    // 1. 連接池優(yōu)化
    httpClient := &http.Client{
        Transport: &http.Transport{
            MaxIdleConns:        10000,
            MaxIdleConnsPerHost: 1000,
            IdleConnTimeout:     90 * time.Second,
            TLSHandshakeTimeout: 10 * time.Second,
        },
        Timeout: 30 * time.Second,
    }

    // 2. 無(wú)鎖數(shù)據(jù)結(jié)構(gòu)
    var counter atomic.Int64
    r.GET("/count", func(c *gin.Context) {
        c.String(200, strconv.FormatInt(counter.Add(1), 10))
    })

    // 3. 對(duì)象池減少GC壓力
    var bufferPool = sync.Pool{
        New: func() interface{} {
            return bytes.NewBuffer(make([]byte, 0, 1024))
        },
    }

    // 啟動(dòng)服務(wù)
    s := &http.Server{
        Addr:           ":8080",
        Handler:        r,
        ReadTimeout:    10 * time.Second,
        WriteTimeout:   10 * time.Second,
        MaxHeaderBytes: 1 << 20,
    }
    s.ListenAndServe()
}

// 使用epoll實(shí)現(xiàn)網(wǎng)絡(luò)層
type epoll struct {
    fd          int
    connections map[int]net.Conn
    lock        sync.RWMutex
}

func (e *epoll) Add(conn net.Conn) error {
    fd := socketFD(conn)
    err := syscall.EpollCtl(e.fd, syscall.EPOLL_CTL_ADD, fd, &syscall.EpollEvent{
        Events: syscall.EPOLLIN|syscall.EPOLLHUP,
        Fd:     int32(fd),
    })
    if err == nil {
        e.lock.Lock()
        defer e.lock.Unlock()
        e.connections[fd] = conn
    }
    return err
}

// 使用syscall.Sendfile實(shí)現(xiàn)文件傳輸
func sendFile(w http.ResponseWriter, r *http.Request) {
    f, _ := os.Open("largefile.iso")
    defer f.Close()
    
    w.Header().Set("Content-Type", "application/octet-stream")
    w.WriteHeader(http.StatusOK)
    
    if _, err := io.CopyN(w, f, 1024 * 1024 * 1024); err != nil {
        log.Println("Send error:", err)
    }
}

// 使用jsoniter替代標(biāo)準(zhǔn)庫(kù)
import "github.com/json-iterator/go"

var json = jsoniter.ConfigFastest

func fastJSONHandler(c *gin.Context) {
    data := map[string]interface{}{...}
    json.NewEncoder(c.Writer).Encode(data)
}

# 使用wrk進(jìn)行基準(zhǔn)測(cè)試
wrk -t12 -c1000 -d60s --latency http://localhost:8080/bench

# 使用vegeta進(jìn)行持續(xù)壓測(cè)
echo "GET http://localhost:8080/api" | vegeta attack -duration=60s -rate=100000 | vegeta report

// 實(shí)時(shí)監(jiān)控指標(biāo)
var (
    qpsGauge = promauto.NewGauge(prometheus.GaugeOpts{
        Name: "service_qps",
        Help: "Current QPS",
    })
    
    latencyHistogram = promauto.NewHistogram(prometheus.HistogramOpts{
        Name:    "request_latency_ms",
        Help:    "Request latency distribution",
        Buckets: []float64{1, 5, 10, 50, 100, 500},
    })
)

func recordMetrics(start time.Time) {
    latency := time.Since(start).Milliseconds()
    latencyHistogram.Observe(float64(latency))
    qpsGauge.Set(currentQPS)
}

graph TD
    A[負(fù)載均衡層] --> B[API網(wǎng)關(guān)層]
    B --> C[業(yè)務(wù)邏輯層]
    C --> D[數(shù)據(jù)訪問(wèn)層]
    D --> E[緩存/DB層]
    
    style A fill:#f9f,stroke:#333
    style B fill:#bbf,stroke:#333

// 使用goleak檢測(cè)
func TestNoLeak(t *testing.T) {
    defer goleak.VerifyNone(t)
    // 測(cè)試代碼
}

// 限制內(nèi)存使用
func init() {
    go func() {
        var m runtime.MemStats
        for {
            runtime.ReadMemStats(&m)
            if m.Alloc > 2 * 1024 * 1024 * 1024 { // 2GB
                log.Fatal("Memory exceeded")
            }
            time.Sleep(1 * time.Second)
        }
    }()
}

// 使用Deadline控制
func handler(ctx context.Context) {
    deadline, ok := ctx.Deadline()
    if ok && time.Until(deadline) < 100*time.Millisecond {
        return // 放棄處理
    }
    // 正常處理
}

echo 'net.ipv4.tcp_tw_reuse = 1' >> /etc/sysctl.conf
echo 'net.core.somaxconn = 32768' >> /etc/sysctl.conf

// 輸出運(yùn)行時(shí)統(tǒng)計(jì)
go func() {
    for {
        log.Printf("Goroutines: %d", runtime.NumGoroutine())
        time.Sleep(5 * time.Second)
    }
}()