// NetIO shares GitChanges on toNet with the network via a multicast group. It
// will pass on GitChanges from the network via fromNet. It uniques the daemon
// instance by changing the .Name member to be name@<host IP>/<original .Name)
func NetIO(l log.Logger, repo Repo, addr *net.UDPAddr, fromNet, toNet chan GitChange) {
var (
err error
recvConn, sendConn *net.UDPConn // UDP connections to allow us to send and receive change updates
)
l.Info("Joining %v multicast(%t) group", addr, addr.IP.IsMulticast())
if recvConn, sendConn, err = establishConnPair(addr); err != nil {
l.Critical("Error joining listening: %s\n", addr, err)
return
}
l.Info("Successfully joined %v multicast(%t) group", addr, addr.IP.IsMulticast())
defer recvConn.Close()
defer sendConn.Close()
hostIp := sendConn.LocalAddr().(*net.UDPAddr).IP.String()
term := false
defer func() { term = true }()
rawFromNet := make(chan []byte, 128)
go func() {
for !term {
b := make([]byte, 1024)
if n, err := recvConn.Read(b); err != nil {
l.Critical("Cannot read socket: %s", err)
continue
} else {
rawFromNet <- b[:n]
}
}
}()
for {
select {
case req, ok := <-toNet:
if !ok {
return
}
req.User = repo.User()
req.HostIp = hostIp
l.Info("Sending %+v", req)
buf := &bytes.Buffer{}
enc := gob.NewEncoder(buf)
if err := enc.Encode(req); err != nil {
l.Critical("%s", err)
continue
}
l.Fine("Sending %+v", buf.Bytes())
if _, err := sendConn.Write(buf.Bytes()); err != nil {
l.Critical("%s", err)
continue
}
case resp := <-rawFromNet:
var change GitChange
dec := gob.NewDecoder(bytes.NewReader(resp))
if err := dec.Decode(&change); err != nil {
l.Critical("%s", err)
continue
} else {
l.Debug("received %+v", change)
}
if rootCommit, err := repo.RootCommit(); err != nil {
log.Critical("Error getting root commit")
} else {
if (repo.User() != change.User) && (rootCommit == change.RootCommit) {
fromNet <- change
}
}
}
}
}
