deterministic rand for rescan trheshold per file

src/asses/one.go

@@ -36,7 +36,15 @@ func One(ctx context.Context, p string) error {
 		return err
 	}
 
-   threshold := 20 + rand.Int()%10
+   threshold := 20 + rand.New(rand.NewSource(func() int64{
+      b := md5.New().Sum([]byte(p))
+      var sum int64
+      for _, c := range b {
+         sum += int64(c)
+         sum *= int64(c)
+      }
+      return sum
+   }())).Int()%10
 	if daysSince := int(time.Since(last.T).Hours()/24);  daysSince > threshold {
       log.Printf("asses.One(%s) // no modified check as %vd since last check", shortp, daysSince)
 	} else if stat, err := os.Stat(p); err != nil {