102 lines
1.7 KiB
Go
102 lines
1.7 KiB
Go
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package mmsg
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import (
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"net"
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"github.com/anacrolix/missinggo/expect"
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"github.com/anacrolix/mmsg/socket"
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)
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// Considered MSG_DONTWAIT, but I think Go puts the socket into non-blocking
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// mode in its runtime and it seems to do the right thing.
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const flags = 0
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type Conn struct {
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err error
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s *socket.Conn
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pr PacketReader
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}
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type PacketReader interface {
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ReadFrom([]byte) (int, net.Addr, error)
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}
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func NewConn(pr PacketReader) *Conn {
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ret := Conn{
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pr: pr,
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}
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ret.s, ret.err = socket.NewConn(pr)
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return &ret
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}
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func (me *Conn) recvMsgAsMsgs(ms []Message) (int, error) {
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err := me.RecvMsg(&ms[0])
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if err != nil {
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return 0, err
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}
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return 1, err
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}
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func (me *Conn) RecvMsgs(ms []Message) (n int, err error) {
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if me.err != nil || len(ms) == 1 {
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return me.recvMsgAsMsgs(ms)
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}
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sms := make([]socket.Message, len(ms))
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for i := range ms {
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sms[i].Buffers = ms[i].Buffers
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}
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n, err = me.s.RecvMsgs(sms, flags)
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if err != nil && err.Error() == "not implemented" {
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expect.Nil(me.err)
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me.err = err
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if n <= 0 {
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return me.recvMsgAsMsgs(ms)
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}
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err = nil
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}
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for i := 0; i < n; i++ {
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ms[i].Addr = sms[i].Addr
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ms[i].N = sms[i].N
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}
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return n, err
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}
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func (me *Conn) RecvMsg(m *Message) error {
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if len(m.Buffers) == 1 { // What about 0?
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var err error
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m.N, m.Addr, err = me.pr.ReadFrom(m.Buffers[0])
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return err
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}
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sm := socket.Message{
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Buffers: m.Buffers,
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}
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err := me.s.RecvMsg(&sm, flags)
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m.Addr = sm.Addr
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m.N = sm.N
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return err
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}
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type Message struct {
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Buffers [][]byte
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N int
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Addr net.Addr
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}
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func (me *Message) Payload() (p []byte) {
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n := me.N
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for _, b := range me.Buffers {
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if len(b) >= n {
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p = append(p, b[:n]...)
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return
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}
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p = append(p, b...)
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n -= len(b)
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}
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panic(n)
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}
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func (me *Conn) Err() error {
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return me.err
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}
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