do relogin periodically to refresh account on API side

utils.go

@@ -12,7 +12,10 @@ import (
 	"time"
 )
 
-const COPY_BUF = 128 * 1024
+const (
+	COPY_BUF = 128 * 1024
+	WALLCLOCK_PRECISION = 1 * time.Second
+)
 
 func basic_auth_header(login, password string) string {
 	return "Basic " + base64.StdEncoding.EncodeToString(
@@ -143,3 +146,40 @@ func copyBody(wr io.Writer, body io.Reader) {
 		}
 	}
 }
+
+func AfterWallClock(d time.Duration) <-chan time.Time {
+    ch := make(chan time.Time, 1)
+    deadline := time.Now().Add(d).Truncate(0)
+    after_ch := time.After(d)
+    ticker := time.NewTicker(WALLCLOCK_PRECISION)
+    go func() {
+        var t time.Time
+        defer ticker.Stop()
+        for {
+            select {
+            case t = <-after_ch:
+                ch <-t
+                return
+            case t = <-ticker.C:
+                if t.After(deadline) {
+                    ch <-t
+                    return
+                }
+            }
+        }
+    }()
+    return ch
+}
+
+func runTicker(ctx context.Context, interval time.Duration, cb func (context.Context)) {
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-AfterWallClock(interval):
+				cb(ctx)
+			}
+		}
+	}()
+}