优化代码结构

gold/link/send.go

@@ -0,0 +1,72 @@
+package link
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/fumiama/WireGold/gold/head"
+	"github.com/sirupsen/logrus"
+)
+
+// Write 向 peer 发包
+func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
+	if len(p.Data) <= int(l.me.mtu) {
+		if !istransfer {
+			p.FillHash()
+			p.Data = l.Encode(p.Data)
+		}
+		return l.write(p, uint32(len(p.Data)), 0, istransfer, false)
+	}
+	if !istransfer {
+		p.FillHash()
+		p.Data = l.Encode(p.Data)
+	}
+	data := p.Data
+	totl := uint32(len(data))
+	i := 0
+	for ; int(totl)-i > int(l.me.mtu); i += int(l.me.mtu) {
+		logrus.Debugln("[link] split frag", i, ":", i+int(l.me.mtu), ", remain:", int(totl)-i-int(l.me.mtu))
+		packet := *p
+		packet.Data = data[:int(l.me.mtu)]
+		cnt, err := l.write(&packet, totl, uint16(uint(i)>>3), istransfer, true)
+		n += cnt
+		if err != nil {
+			return n, err
+		}
+		data = data[int(l.me.mtu):]
+	}
+	p.Data = data
+	cnt, err := l.write(p, totl, uint16(uint(i)>>3), istransfer, false)
+	n += cnt
+	if err != nil {
+		return n, err
+	}
+	return n, nil
+}
+
+// write 向 peer 发一个包
+func (l *Link) write(p *head.Packet, datasz uint32, offset uint16, istransfer, hasmore bool) (n int, err error) {
+	var d []byte
+	var cl func()
+	if istransfer {
+		if p.Flags&0x4000 == 0x4000 && len(p.Data) > int(l.me.mtu) {
+			return len(p.Data), errors.New("drop dont fragmnet big trans packet")
+		}
+		d, cl = p.Marshal(nil, 0, 0, false, false)
+	} else {
+		d, cl = p.Marshal(l.me.me, datasz, offset, false, hasmore)
+	}
+	if d == nil {
+		return 0, errors.New("[link] ttl exceeded")
+	}
+	if err == nil {
+		peerep := l.endpoint
+		if peerep == nil {
+			return 0, errors.New("[link] nil endpoint of " + p.Dst.String())
+		}
+		logrus.Debugln("[link] write", len(d), "bytes data from ep", l.me.myep.LocalAddr(), "to", peerep, "offset:", fmt.Sprintf("%04x", offset))
+		n, err = l.me.myep.WriteToUDP(d, peerep)
+		cl()
+	}
+	return
+}