herald.go/server/notifier.go
2022-12-07 04:07:26 +00:00

125 lines
2.6 KiB
Go

package server
import (
"encoding/binary"
"net"
"github.com/lbryio/herald.go/internal"
"github.com/sirupsen/logrus"
)
const NotifierResponseLength = 40
// AddHeightSub adds a new height subscriber
func (s *Server) AddHeightSub(addr net.Addr, conn net.Conn) {
s.HeightSubsMut.Lock()
defer s.HeightSubsMut.Unlock()
s.HeightSubs[addr] = conn
}
// DoNotify sends a notification to all height subscribers
func (s *Server) DoNotify(heightHash *internal.HeightHash) error {
buff := make([]byte, NotifierResponseLength)
toDelete := make([]net.Addr, 0)
s.HeightSubsMut.RLock()
for addr, conn := range s.HeightSubs {
// struct.pack(b'>Q32s', height, block_hash)
binary.BigEndian.PutUint64(buff, heightHash.Height)
copy(buff[8:], heightHash.BlockHash[:32])
logrus.Tracef("notifying %s", addr)
n, err := conn.Write(buff)
if err != nil {
logrus.Warn(err)
toDelete = append(toDelete, addr)
}
if n != NotifierResponseLength {
logrus.Warn("not all bytes written")
}
}
s.HeightSubsMut.RUnlock()
if len(toDelete) > 0 {
s.HeightSubsMut.Lock()
for _, v := range toDelete {
delete(s.HeightSubs, v)
}
s.HeightSubsMut.Unlock()
}
return nil
}
// RunNotifier Runs the notfying action forever
func (s *Server) RunNotifier() error {
for notification := range s.NotifierChan {
switch notification.(type) {
case internal.HeightHash:
heightHash, _ := notification.(internal.HeightHash)
s.DoNotify(&heightHash)
// Do we need this?
// case peerNotification:
// peer, _ := notification.(peerNotification)
// s.notifyPeerSubs(&Peer{Address: peer.address, Port: peer.port})
default:
logrus.Warn("unknown notification type")
}
s.sessionManager.doNotify(notification)
}
return nil
}
// NotifierServer implements the TCP protocol for height/blockheader notifications
func (s *Server) NotifierServer() error {
s.Grp.Add(1)
address := ":" + s.Args.NotifierPort
addr, err := net.ResolveTCPAddr("tcp", address)
if err != nil {
return err
}
listen, err := net.ListenTCP("tcp", addr)
if err != nil {
return err
}
defer listen.Close()
rdyCh := make(chan bool)
for {
var conn net.Conn
var err error
logrus.Info("Waiting for connection")
go func() {
conn, err = listen.Accept()
rdyCh <- true
}()
select {
case <-s.Grp.Ch():
s.Grp.Done()
return nil
case <-rdyCh:
logrus.Info("Connection accepted")
}
if err != nil {
logrus.Warn(err)
continue
}
addr := conn.RemoteAddr()
logrus.Println(addr)
// _, err = conn.Write([]byte(addr.String()))
// if err != nil {
// logrus.Warn(err)
// continue
// }
go s.AddHeightSub(addr, conn)
}
}