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//
// rhctl
//
// Copyright (C) 2009-2016 Christian Pointner <equinox@helsinki.at>
//
// This file is part of rhctl.
//
// rhctl is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// rhctl is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with rhctl. If not, see <http://www.gnu.org/licenses/>.
//
package main
import (
"fmt"
"strings"
"time"
"code.helsinki.at/goserial"
)
type ServerHealth bool
const (
ServerDead ServerHealth = false
ServerAlive ServerHealth = true
ServerChannelReq = "channel?"
)
func (s ServerHealth) String() string {
switch s {
case ServerDead:
return "dead"
case ServerAlive:
return "alive"
}
return "unknown"
}
func (s ServerHealth) MarshalText() (data []byte, err error) {
data = []byte(s.String())
return
}
type ServerState struct {
Name string
Health ServerHealth
ResurrectionLevel float64
Channel string
Updated time.Time
}
type PlayoutServer struct {
name string
device *goserial.Port
hbtimeout time.Duration
hbtimer *time.Timer
hbthreshold uint
hbcnt uint
state ServerState
StateChanges chan ServerState
Commands chan Command
UpdateRequest chan bool
SwitchUpdates chan SwitchUpdate
}
func (srv *PlayoutServer) handleHeartbeat() {
srv.hbtimer.Reset(srv.hbtimeout)
if (srv.hbcnt + 1) < srv.hbthreshold {
srv.hbcnt++
srv.state.ResurrectionLevel = float64(srv.hbcnt) / float64(srv.hbthreshold)
srv.StateChanges <- srv.state
return
}
old := srv.state.Health
srv.state.Health = ServerAlive
srv.state.ResurrectionLevel = 1.0
srv.state.Updated = time.Now()
if old != srv.state.Health {
srv.StateChanges <- srv.state
rhl.Printf("Server(%s): is back from the dead!", srv.name)
if srv.state.Channel == "" {
srv.device.TX <- ServerChannelReq
}
}
}
func (srv *PlayoutServer) handleMessage(data string) {
if data == "hb" {
// rhdl.Printf("Server(%s): got heartbeat message", srv.name)
srv.handleHeartbeat()
return
}
rhdl.Printf("Server(%s): got message: %q", srv.name, data)
if strings.HasPrefix(data, "channel ") {
if len(data) <= 8 {
rhl.Printf("Server(%s) sent empty channel name", srv.name)
return
}
srv.state.Channel = data[8:]
srv.state.Updated = time.Now()
srv.Commands <- Command{Type: CmdChannel, Args: []string{srv.name, data[8:]}, Response: nil}
srv.StateChanges <- srv.state
return
}
if strings.HasPrefix(data, "handover ") {
if len(data) <= 9 {
rhl.Printf("Server(%s) sent empty handover", srv.name)
return
}
srv.Commands <- Command{Type: CmdServer, Args: []string{data[9:]}, Response: nil}
return
}
rhl.Printf("Server(%s): ignoring unknown message: %q", srv.name, data)
}
func (srv *PlayoutServer) handleHBTimeout() {
rhl.Printf("Server(%s): heartbeat timed-out", srv.name)
srv.hbcnt = 0
srv.state.Health = ServerDead
srv.state.ResurrectionLevel = 0.0
srv.state.Updated = time.Now()
srv.StateChanges <- srv.state
}
func (srv *PlayoutServer) Run() {
stop := make(chan bool)
srv.device.Run(stop)
srv.hbtimer = time.NewTimer(srv.hbtimeout)
srv.hbcnt = 0
srv.state.ResurrectionLevel = 0.0
rhdl.Printf("Server(%s): handler running...", srv.name)
for {
select {
case <-stop:
return
case data := <-srv.device.RX:
srv.handleMessage(data)
case <-srv.hbtimer.C:
srv.handleHBTimeout()
case <-srv.UpdateRequest:
if srv.state.Health == ServerDead {
srv.StateChanges <- srv.state
} else {
srv.device.TX <- ServerChannelReq
}
case update := <-srv.SwitchUpdates:
srv.device.TX <- update.Data
}
}
}
func ServerInit(name string, conf *Config) (srv *PlayoutServer, err error) {
srv = &PlayoutServer{}
srv.name = name
srv.hbtimeout = 3 * time.Second
if conf.Servers[name].HeartbeatTimeout.Duration > time.Duration(0) {
srv.hbtimeout = conf.Servers[name].HeartbeatTimeout.Duration
}
srv.hbthreshold = 10
if conf.Servers[name].HeartbeatThreshold > 0 {
srv.hbthreshold = conf.Servers[name].HeartbeatThreshold
}
srv.state.Name = srv.name
srv.state.Health = ServerDead
srv.state.ResurrectionLevel = 0.0
srv.state.Channel = ""
srv.StateChanges = make(chan ServerState, 16)
srv.Commands = make(chan Command, 8)
srv.UpdateRequest = make(chan bool, 8)
srv.SwitchUpdates = make(chan SwitchUpdate, 32)
if srv.device, err = goserial.Open(conf.Servers[name].Device, conf.Servers[name].Baudrate, "\n"); err != nil {
err = fmt.Errorf("Server(%s): error opening serial port: %s", srv.name, err)
return
}
return
}
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