init

reload.go

@@ -0,0 +1,65 @@
+package gost
+
+import (
+	"io"
+	"os"
+	"time"
+
+	"github.com/go-log/log"
+)
+
+// Reloader is the interface for objects that support live reloading.
+type Reloader interface {
+	Reload(r io.Reader) error
+	Period() time.Duration
+}
+
+// Stoppable is the interface that indicates a Reloader can be stopped.
+type Stoppable interface {
+	Stop()
+	Stopped() bool
+}
+
+// PeriodReload reloads the config configFile periodically according to the period of the Reloader r.
+func PeriodReload(r Reloader, configFile string) error {
+	if r == nil || configFile == "" {
+		return nil
+	}
+
+	var lastMod time.Time
+	for {
+		if r.Period() < 0 {
+			log.Log("[reload] stopped:", configFile)
+			return nil
+		}
+
+		f, err := os.Open(configFile)
+		if err != nil {
+			return err
+		}
+
+		mt := lastMod
+		if finfo, err := f.Stat(); err == nil {
+			mt = finfo.ModTime()
+		}
+
+		if !lastMod.IsZero() && !mt.Equal(lastMod) {
+			log.Log("[reload]", configFile)
+			if err := r.Reload(f); err != nil {
+				log.Logf("[reload] %s: %s", configFile, err)
+			}
+		}
+		f.Close()
+		lastMod = mt
+
+		period := r.Period()
+		if period == 0 {
+			log.Log("[reload] disabled:", configFile)
+			return nil
+		}
+		if period < time.Second {
+			period = time.Second
+		}
+		<-time.After(period)
+	}
+}