opt: put the bytes of net.Addr.Zone back to pool when connection is c…

…losed

Fixes #364

connection.go

@@ -29,6 +29,7 @@ import (
 	gio "github.com/panjf2000/gnet/v2/internal/io"
 	"github.com/panjf2000/gnet/v2/internal/netpoll"
 	"github.com/panjf2000/gnet/v2/internal/socket"
+	"github.com/panjf2000/gnet/v2/internal/toolkit"
 	"github.com/panjf2000/gnet/v2/pkg/buffer/elastic"
 	gerrors "github.com/panjf2000/gnet/v2/pkg/errors"
 	bsPool "github.com/panjf2000/gnet/v2/pkg/pool/byteslice"
@@ -70,9 +71,15 @@ func (c *conn) releaseTCP() {
 	c.buffer = nil
 	if addr, ok := c.localAddr.(*net.TCPAddr); ok && c.localAddr != c.loop.ln.addr {
 		bsPool.Put(addr.IP)
+		if len(addr.Zone) > 0 {
+			bsPool.Put(toolkit.StringToBytes(addr.Zone))
+		}
 	}
 	if addr, ok := c.remoteAddr.(*net.TCPAddr); ok {
 		bsPool.Put(addr.IP)
+		if len(addr.Zone) > 0 {
+			bsPool.Put(toolkit.StringToBytes(addr.Zone))
+		}
 	}
 	c.localAddr = nil
 	c.remoteAddr = nil
@@ -101,9 +108,15 @@ func (c *conn) releaseUDP() {
 	c.ctx = nil
 	if addr, ok := c.localAddr.(*net.UDPAddr); ok && c.localAddr != c.loop.ln.addr {
 		bsPool.Put(addr.IP)
+		if len(addr.Zone) > 0 {
+			bsPool.Put(toolkit.StringToBytes(addr.Zone))
+		}
 	}
 	if addr, ok := c.remoteAddr.(*net.UDPAddr); ok {
 		bsPool.Put(addr.IP)
+		if len(addr.Zone) > 0 {
+			bsPool.Put(toolkit.StringToBytes(addr.Zone))
+		}
 	}
 	c.localAddr = nil
 	c.remoteAddr = nil

internal/socket/socktoaddr.go

@@ -22,6 +22,7 @@ import (
 
 	"golang.org/x/sys/unix"
 
+	"github.com/panjf2000/gnet/v2/internal/toolkit"
 	bsPool "github.com/panjf2000/gnet/v2/pkg/pool/byteslice"
 )
 
@@ -100,5 +101,5 @@ func int2decimal(i uint) string {
 		bp--
 		b[bp] = byte(i%10) + '0'
 	}
-	return string(b[bp:])
+	return toolkit.BytesToString(b[bp:])
 }