func (server *Server) serve(clientid int64, clientCommitCh chan ClientResponse, conn *net.TCPConn) {
reader := bufio.NewReader(conn)
var res ClientResponse
var response *fs.Msg
for {
msg, msgerr, fatalerr := fs.GetMsg(clientid, reader)
// msg.ClientId=clientid
if fatalerr != nil {
reply(conn, &fs.Msg{Kind: 'M'})
conn.Close()
break
}
if msgerr != nil {
if (!reply(conn, &fs.Msg{Kind: 'M'})) {
conn.Close()
break
}
continue
}
// if message not of read type
if msg.Kind == 'w' || msg.Kind == 'c' || msg.Kind == 'd' {
dbytes, err := encode(*msg)
if err != nil {
if (!reply(conn, &fs.Msg{Kind: 'I'})) {
conn.Close()
break
}
continue
}
// append the msg to the raft node log
server.rn.Append(dbytes)
//wait for the msg to appear on the client commit channel
res = <-clientCommitCh
if res.Err != nil {
msgContent := server.getAddress(server.rn.LeaderId())
// fmt.Printf("Leader address : %v\n", rc.LeaderId())
reply(conn, &fs.Msg{Kind: 'R', Contents: []byte(msgContent)})
conn.Close()
break
}
response = res.Message
// fmt.Printf("Response Message %v\n", string(response.Contents))
} else if msg.Kind == 'r' {
response = fs.ProcessMsg(server.fileMap, &(server.gversion), msg)
}
if !reply(conn, response) {
conn.Close()
break
}
}
}
func (server *Server) ListenCommitChannel() {
getMsg := func(index int) {
err, emsg := server.rn.Get(index)
if err != nil {
fmt.Printf("ListenCommitChannel: Error in getting message 4")
assert(err == nil)
}
dmsg, err := decode(emsg)
if err != nil {
fmt.Printf("ListenCommitChannel: Error in decoding message 3")
assert(err == nil)
}
response := fs.ProcessMsg(server.fileMap, &(server.gversion), &dmsg)
server.Lock()
if ch, ok := server.ClientChanMap[dmsg.ClientId]; ok {
ch <- ClientResponse{response, nil}
}
server.Unlock()
}
var prevLogIndexProcessed = -1
for {
//listen on commit channel of raft node
commitval := <-server.rn.CommitChannel()
if commitval.Err != nil {
//Redirect the client. Assume the server for which this server voted is the leader. So, redirect it there.
dmsg, err := decode(commitval.Data)
if err != nil {
fmt.Printf("ListenCommitChannel: Error in decoding message 1")
assert(err == nil)
}
server.Lock()
if ch, ok := server.ClientChanMap[dmsg.ClientId]; ok {
ch <- ClientResponse{nil, errors.New("ERR_REDIRECT")}
}
server.Unlock()
} else {
//check if there are missing or duplicate commits
if commitval.Index <= prevLogIndexProcessed {
// already processed. So continue
continue
}
// if missing get them
for i := prevLogIndexProcessed + 1; i < commitval.Index; i++ {
getMsg(i)
}
dmsg, err := decode(commitval.Data)
if err != nil {
fmt.Printf("ListenCommitChannel: Error in decoding message 3")
assert(err == nil)
}
// process the message and send response to client
response := fs.ProcessMsg(server.fileMap, &(server.gversion), &dmsg)
// fmt.Printf("Response: %v", *response)
//server.ClientChanMap[dmsg.ClientId]<-ClientEntry{dmsg,nil}
server.Lock()
if ch, ok := server.ClientChanMap[dmsg.ClientId]; ok {
ch <- ClientResponse{response, nil}
}
server.Unlock()
prevLogIndexProcessed = commitval.Index
}
}
}