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Added inotify watcher for restarting slideshow when files are changed/deleted/added

master
KemoNine 8 months ago
parent
commit
88b60f2df0
  1. 3
      cmd/inotify/README.md
  2. 68
      cmd/inotify/inotify.go
  3. 3
      watchdog/README.md
  4. 41
      watchdog/watchdog.go

3
cmd/inotify/README.md

@ -0,0 +1,3 @@
# inotify
This is the main source code for the inotify watcher that restarts the PiFrame slide show when files have changed (add/remove/etc).

68
cmd/inotify/inotify.go

@ -0,0 +1,68 @@
package main
import (
"log"
"os/exec"
"time"
"github.com/dietsche/rfsnotify"
"git.kemonine.info/PiFrame/watchdog"
)
const (
CMD_SYSTEMCTL = "/usr/bin/systemctl"
PATH_PICTURES = "/tank/pictures"
TIMEOUT = 5 * time.Second
)
func main() {
// Create watchdog timer that restarts fim.service on timeout
watchdog := watchdog.New(TIMEOUT, func() {
err := exec.Command(CMD_SYSTEMCTL, "restart", "fim.service").Run()
if err != nil {
log.Fatalf("Error running %s : %s", CMD_SYSTEMCTL, err)
}
})
watchdog.DeferredStart()
// Create fswatcher
watcher, err := rfsnotify.NewWatcher()
if err != nil {
log.Fatal("Error setting up rfsnotify")
}
// Ensure we clean stuff up no matter what
defer watcher.Close()
// Setup goroutine and listen for events
done := make(chan bool)
go func() {
for {
select {
case event, ok := <-watcher.Events:
if !ok {
return
}
// Print out event (this is where logic will go eventually))
log.Printf("event: %#v\n", event)
// [Re]Start timer to restart slideshow after the fs events die down
watchdog.Kick()
case err, ok := <-watcher.Errors:
if !ok {
return
}
log.Println("Error: ", err)
}
}
}()
// Setup paths to watch
err = watcher.AddRecursive(PATH_PICTURES)
if err != nil {
log.Fatalf("Error setting up recursive watch of %s", PATH_PICTURES)
}
// Drain done channel...
<-done
}

3
watchdog/README.md

@ -0,0 +1,3 @@
# watchdog
A very simple watchdog timer implementation. Borrowed from [here](https://codereview.stackexchange.com/questions/144273/watchdog-in-golang) and tweaked slightly.

41
watchdog/watchdog.go

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// Adapted from https://codereview.stackexchange.com/questions/144273/watchdog-in-golang
package watchdog
import (
"time"
)
type watchdog struct {
interval time.Duration
callback func()
timer *time.Timer
}
func New(interval time.Duration, callback func()) *watchdog {
w := watchdog{
interval: interval,
callback: callback,
timer: nil,
}
return &w
}
func (w *watchdog) Start() {
w.timer = time.AfterFunc(w.interval, w.callback)
}
// Helper to allow the watchdog to be started by a call to Kick directly
func (w *watchdog) DeferredStart() {
w.Start()
w.Stop()
}
func (w *watchdog) Stop() {
w.timer.Stop()
}
func (w *watchdog) Kick() {
w.Stop()
w.timer.Reset(w.interval)
}
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