jeol-t330a/succd/main.go
2024-09-12 03:02:57 +02:00

114 lines
2.4 KiB
Go

package main
import (
"context"
"errors"
"flag"
"fmt"
"math"
"net/http"
"os"
"os/signal"
"sync"
"time"
"k8s.io/klog"
)
// daemon is the main state of the succdaemon.
type daemon struct {
// adcPirani is the adc implementation returning the voltage of the Pfeiffer
// Pirani gauge.
adcPirani adc
// mu guards state variables below.
mu sync.RWMutex
// adcPiraniVolts is the last readout of adcPirani.
adcPiraniVolts float32
}
// process runs the pain acquisition and control loop of succd.
func (d *daemon) process(ctx context.Context) {
ticker := time.NewTicker(time.Millisecond * 100)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if err := d.processOnce(ctx); err != nil {
if errors.Is(err, ctx.Err()) {
return
} else {
klog.Errorf("Processing error: %v", err)
time.Sleep(time.Second * 10)
}
}
case <-ctx.Done():
return
}
}
}
// processOnce runs the main loop step of succd.
func (d *daemon) processOnce(_ context.Context) error {
v, err := d.adcPirani.Read()
if err != nil {
return fmt.Errorf("when reading ADC: %w", err)
}
d.mu.Lock()
d.adcPiraniVolts = v
d.mu.Unlock()
return nil
}
// pirani returns the Pirani gauge voltage and pressure.
func (d *daemon) pirani() (volts float32, mbar float32) {
d.mu.RLock()
volts = d.adcPiraniVolts
d.mu.RUnlock()
// Per Pirani probe docs.
bar := math.Pow(10.0, float64(volts)-8.5)
mbar = float32(bar * 1000.0)
return
}
var (
flagFake bool
flagListenHTTP string
)
func main() {
flag.BoolVar(&flagFake, "fake", false, "Enable fake mode which allows to run succd for tests outside the succbone")
flag.StringVar(&flagListenHTTP, "listen_http", ":8080", "Address at which to listen for HTTP requests")
flag.Parse()
ctx, _ := signal.NotifyContext(context.Background(), os.Interrupt)
d := daemon{}
if flagFake {
klog.Infof("Starting with fake Pirani probe")
d.adcPirani = &fakeADC{}
} else {
adc, err := newBBADC(0)
if err != nil {
klog.Exitf("Failed to setup Pirani ADC: %v", err)
}
d.adcPirani = adc
}
http.HandleFunc("/", d.httpIndex)
http.HandleFunc("/stream", d.httpStream)
http.HandleFunc("/metrics", d.httpMetrics)
klog.Infof("Listening for HTTP at %s", flagListenHTTP)
go func() {
if err := http.ListenAndServe(flagListenHTTP, nil); err != nil {
klog.Errorf("HTTP listen failed: %v", err)
}
}()
go d.process(ctx)
<-ctx.Done()
}