func main() {
if *showVersion {
log.Printf("nats-top v%s", version)
os.Exit(0)
}
opts := map[string]interface{}{}
opts["host"] = *host
opts["port"] = *port
opts["conns"] = *conns
opts["delay"] = *delay
if opts["host"] == nil || opts["port"] == nil {
log.Fatalf("Please specify the monitoring port for NATS.\n")
usage()
}
sortOpt := gnatsd.SortOpt(*sortBy)
switch sortOpt {
case SortByCid, SortBySubs, SortByPending, SortByOutMsgs, SortByInMsgs, SortByOutBytes, SortByInBytes:
opts["sort"] = sortOpt
default:
log.Printf("nats-top: not a valid option to sort by: %s\n", sortOpt)
usage()
}
err := ui.Init()
if err != nil {
panic(err)
}
defer ui.Close()
statsCh := make(chan *Stats)
shutdownCh := make(chan struct{})
go MonitorStats(opts, statsCh, shutdownCh)
StartUI(opts, statsCh, shutdownCh)
}
// StartUI periodically refreshes the screen using recent data
func StartUI(
opts map[string]interface{},
statsCh chan *Stats,
shutdownCh chan struct{},
) {
cleanStats := &Stats{
Varz: &gnatsd.Varz{},
Connz: &gnatsd.Connz{},
Rates: &Rates{},
}
// Show empty values on first display
text := generateParagraph(opts, cleanStats)
par := ui.NewPar(text)
par.Height = ui.TermHeight()
par.Width = ui.TermWidth()
par.HasBorder = false
helpText := generateHelp()
helpPar := ui.NewPar(helpText)
helpPar.Height = ui.TermHeight()
helpPar.Width = ui.TermWidth()
helpPar.HasBorder = false
// Top like view
paraRow := ui.NewRow(ui.NewCol(ui.TermWidth(), 0, par))
// Help view
helpParaRow := ui.NewRow(ui.NewCol(ui.TermWidth(), 0, helpPar))
// Create grids that we'll be using to toggle what to render
topViewGrid := ui.NewGrid(paraRow)
helpViewGrid := ui.NewGrid(helpParaRow)
// Start with the topviewGrid by default
ui.Body.Rows = topViewGrid.Rows
ui.Body.Align()
// Used to toggle back to previous mode
viewMode := TopViewMode
// Used for pinging the IU to refresh the screen with new values
redraw := make(chan struct{})
update := func() {
for {
stats := <-statsCh
// Update top view text
text = generateParagraph(opts, stats)
par.Text = text
redraw <- struct{}{}
}
}
// Flags for capturing options
waitingSortOption := false
waitingLimitOption := false
displaySubscriptions := false
optionBuf := ""
refreshOptionHeader := func() {
// Need to mask what was typed before
clrline := "\033[1;1H\033[6;1H "
clrline += " "
for i := 0; i < len(optionBuf); i++ {
clrline += " "
}
fmt.Printf(clrline)
}
evt := ui.EventCh()
ui.Render(ui.Body)
go update()
for {
select {
case e := <-evt:
if waitingSortOption {
if e.Type == ui.EventKey && e.Key == ui.KeyEnter {
sortOpt := gnatsd.SortOpt(optionBuf)
switch sortOpt {
case SortByCid, SortBySubs, SortByPending, SortByOutMsgs, SortByInMsgs, SortByOutBytes, SortByInBytes:
opts["sort"] = sortOpt
default:
go func() {
// Has to be at least of the same length as sort by header
emptyPadding := " "
fmt.Printf("\033[1;1H\033[6;1Hinvalid order: %s%s", optionBuf, emptyPadding)
waitingSortOption = false
time.Sleep(1 * time.Second)
refreshOptionHeader()
optionBuf = ""
}()
continue
}
refreshOptionHeader()
waitingSortOption = false
optionBuf = ""
continue
}
// Handle backspace
if e.Type == ui.EventKey && len(optionBuf) > 0 && (e.Key == ui.KeyBackspace || e.Key == ui.KeyBackspace2) {
optionBuf = optionBuf[:len(optionBuf)-1]
refreshOptionHeader()
} else {
optionBuf += string(e.Ch)
}
fmt.Printf("\033[1;1H\033[6;1Hsort by [%s]: %s", opts["sort"], optionBuf)
}
if waitingLimitOption {
if e.Type == ui.EventKey && e.Key == ui.KeyEnter {
var n int
_, err := fmt.Sscanf(optionBuf, "%d", &n)
if err == nil {
opts["conns"] = n
}
waitingLimitOption = false
optionBuf = ""
refreshOptionHeader()
continue
}
// Handle backspace
if e.Type == ui.EventKey && len(optionBuf) > 0 && (e.Key == ui.KeyBackspace || e.Key == ui.KeyBackspace2) {
optionBuf = optionBuf[:len(optionBuf)-1]
refreshOptionHeader()
} else {
optionBuf += string(e.Ch)
}
fmt.Printf("\033[1;1H\033[6;1Hlimit [%d]: %s", opts["conns"], optionBuf)
}
if e.Type == ui.EventKey && (e.Ch == 'q' || e.Key == ui.KeyCtrlC) {
close(shutdownCh)
cleanExit()
}
if e.Type == ui.EventKey && e.Ch == 's' && !(waitingLimitOption || waitingSortOption) {
if displaySubscriptions {
displaySubscriptions = false
opts["subs"] = false
} else {
displaySubscriptions = true
opts["subs"] = true
}
}
if e.Type == ui.EventKey && viewMode == HelpViewMode {
ui.Body.Rows = topViewGrid.Rows
viewMode = TopViewMode
continue
}
if e.Type == ui.EventKey && e.Ch == 'o' && !waitingLimitOption && viewMode == TopViewMode {
fmt.Printf("\033[1;1H\033[6;1Hsort by [%s]:", opts["sort"])
waitingSortOption = true
}
if e.Type == ui.EventKey && e.Ch == 'n' && !waitingSortOption && viewMode == TopViewMode {
fmt.Printf("\033[1;1H\033[6;1Hlimit [%d]:", opts["conns"])
waitingLimitOption = true
}
if e.Type == ui.EventKey && (e.Ch == '?' || e.Ch == 'h') && !(waitingSortOption || waitingLimitOption) {
if viewMode == TopViewMode {
refreshOptionHeader()
optionBuf = ""
}
ui.Body.Rows = helpViewGrid.Rows
viewMode = HelpViewMode
waitingLimitOption = false
waitingSortOption = false
}
if e.Type == ui.EventResize {
ui.Body.Width = ui.TermWidth()
ui.Body.Align()
go func() { redraw <- struct{}{} }()
}
case <-redraw:
ui.Render(ui.Body)
}
}
}