feat(conn): 自 go-hua 迁入限速统计连接装饰器

- net.Conn 透明叠加 rate 限速与 flow 流量统计
- 内部依赖改指 zogo/flow 与 zogo/rate, 附测试、例程与 README

conn/conn_test.go

@@ -0,0 +1,132 @@
+package conn
+
+import (
+	"io"
+	"net"
+	"sync"
+	"testing"
+	"time"
+
+	"git.zeroonesoft.cn/golib/zogo/flow"
+	"git.zeroonesoft.cn/golib/zogo/rate"
+)
+
+func TestConnWriteReadFlow(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c2.Close()
+
+	f := &flow.Flow{}
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	c := NewConn(c1, nil, f, wg)
+	defer c.Close()
+
+	// 持续消费对端数据，避免 Write 阻塞
+	done := make(chan struct{})
+	go func() {
+		buf := make([]byte, 1024)
+		for {
+			if _, err := c2.Read(buf); err != nil {
+				close(done)
+				return
+			}
+		}
+	}()
+
+	if n, err := c.Write([]byte("hello")); err != nil || n != 5 {
+		t.Fatalf("Write = %d, %v, want 5, nil", n, err)
+	}
+
+	// 对端写入，本端读取
+	go func() {
+		c2.Write([]byte("abcde"))
+	}()
+	buf := make([]byte, 5)
+	if err := c.SetReadDeadline(time.Now().Add(2 * time.Second)); err != nil {
+		t.Logf("SetReadDeadline: %v（conn.Read 未实现 Deadline 转发）", err)
+	}
+	n, err := c.Read(buf)
+	if err != nil || n != 5 {
+		t.Fatalf("Read = %d, %v, want 5, nil", n, err)
+	}
+
+	// conn 包设计：Read/Write 均计入 SendFlow
+	send, _ := f.Get()
+	if send != 10 {
+		t.Errorf("Flow SendFlow = %d, want 10（读写各计 5）", send)
+	}
+
+	// 触发消费者协程退出：关闭本端后其阻塞在 c2.Read 的 goroutine 会返回
+	c.Close()
+	<-done
+}
+
+func TestConnCloseIdempotent(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c2.Close()
+
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	c := NewConn(c1, nil, nil, wg)
+
+	if err := c.Close(); err != nil {
+		t.Fatalf("第一次 Close: %v", err)
+	}
+	_ = c.Close() // 第二次 Close 不应重复 wg.Done
+
+	finished := make(chan struct{})
+	go func() {
+		wg.Wait()
+		close(finished)
+	}()
+	select {
+	case <-finished:
+		// 正常：wg 只被 Done 一次
+	case <-time.After(time.Second):
+		t.Error("Close 幂等性失败：wg 被多次 Done 或未被 Done")
+	}
+}
+
+func TestConnAddr(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c1.Close()
+	defer c2.Close()
+
+	c := NewConn(c1, nil, nil, nil)
+	defer c.Close()
+
+	if c.LocalAddr() == nil || c.RemoteAddr() == nil {
+		t.Error("LocalAddr/RemoteAddr 不应为 nil")
+	}
+}
+
+func TestConnWithRateLimit(t *testing.T) {
+	c1, c2 := net.Pipe()
+	defer c2.Close()
+
+	// 不限速：Add 应立即返回
+	r := rate.NewRate(0)
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	c := NewConn(c1, r, nil, wg)
+	defer c.Close()
+
+	readerDone := make(chan struct{})
+	go func() {
+		defer close(readerDone)
+		buf := make([]byte, 1024)
+		for {
+			if _, err := c2.Read(buf); err != nil {
+				return
+			}
+		}
+	}()
+
+	if _, err := io.WriteString(c, "x"); err != nil {
+		t.Fatalf("Write: %v", err)
+	}
+
+	// 关闭本端使消费者协程退出，避免 goroutine 泄漏
+	_ = c.Close()
+	<-readerDone
+}