feat: reduce the type assertion of CheckConn

Signed-off-by: monkey <[email protected]>

Author: monkey92t

internal/pool/conn.go

@@ -3,8 +3,10 @@ package pool
 import (
 	"bufio"
 	"context"
+	"crypto/tls"
 	"net"
 	"sync/atomic"
+	"syscall"
 	"time"
 
 	"github.com/redis/go-redis/v9/internal/proto"
@@ -16,6 +18,9 @@ type Conn struct {
 	usedAt  int64 // atomic
 	netConn net.Conn
 
+	// for checking the health status of the connection, it may be nil.
+	rawConn syscall.RawConn
+
 	rd *proto.Reader
 	bw *bufio.Writer
 	wr *proto.Writer
@@ -34,6 +39,7 @@ func NewConn(netConn net.Conn) *Conn {
 	cn.bw = bufio.NewWriter(netConn)
 	cn.wr = proto.NewWriter(cn.bw)
 	cn.SetUsedAt(time.Now())
+	cn.setRawConn()
 	return cn
 }
 
@@ -50,6 +56,23 @@ func (cn *Conn) SetNetConn(netConn net.Conn) {
 	cn.netConn = netConn
 	cn.rd.Reset(netConn)
 	cn.bw.Reset(netConn)
+	cn.setRawConn()
+}
+
+func (cn *Conn) setRawConn() {
+	conn := cn.netConn
+	if conn == nil {
+		return
+	}
+	if tlsConn, ok := conn.(*tls.Conn); ok {
+		conn = tlsConn.NetConn()
+	}
+
+	if sysConn, ok := conn.(syscall.Conn); ok {
+		if rawConn, err := sysConn.SyscallConn(); err == nil {
+			cn.rawConn = rawConn
+		}
+	}
 }
 
 func (cn *Conn) Write(b []byte) (int, error) {

internal/pool/conn_check.go

@@ -3,35 +3,15 @@
 package pool
 
 import (
-	"crypto/tls"
 	"errors"
 	"io"
-	"net"
 	"syscall"
-	"time"
 )
 
 var errUnexpectedRead = errors.New("unexpected read from socket")
 
-func connCheck(conn net.Conn) error {
-	// Reset previous timeout.
-	_ = conn.SetDeadline(time.Time{})
-
-	// Check if tls.Conn.
-	if c, ok := conn.(*tls.Conn); ok {
-		conn = c.NetConn()
-	}
-	sysConn, ok := conn.(syscall.Conn)
-	if !ok {
-		return nil
-	}
-	rawConn, err := sysConn.SyscallConn()
-	if err != nil {
-		return err
-	}
-
+func connCheck(rawConn syscall.RawConn) error {
 	var sysErr error
-
 	if err := rawConn.Read(func(fd uintptr) bool {
 		var buf [1]byte
 		n, err := syscall.Read(int(fd), buf[:])

internal/pool/conn_check_dummy.go

@@ -2,8 +2,10 @@
 
 package pool
 
-import "net"
+import (
+	"syscall"
+)
 
-func connCheck(conn net.Conn) error {
+func connCheck(_ syscall.RawConn) error {
 	return nil
 }

internal/pool/pool.go

@@ -499,6 +499,8 @@ func (p *ConnPool) Close() error {
 	return firstErr
 }
 
+var zeroTime = time.Time{}
+
 func (p *ConnPool) isHealthyConn(cn *Conn) bool {
 	now := time.Now()
 
@@ -509,8 +511,12 @@ func (p *ConnPool) isHealthyConn(cn *Conn) bool {
 		return false
 	}
 
-	if connCheck(cn.netConn) != nil {
-		return false
+	if cn.rawConn != nil {
+		// reset previous timeout.
+		_ = cn.netConn.SetDeadline(zeroTime)
+		if connCheck(cn.rawConn) != nil {
+			return false
+		}
 	}
 
 	cn.SetUsedAt(now)