added multi

multi.go

@@ -0,0 +1,39 @@
+package bps
+
+import "time"
+
+// Multi wraps multiple BPS
+type Multi struct {
+	bs []*BPS
+}
+
+// NewMulti returns a populated Multi that has a BPS for each provided
+// duration.
+func NewMulti(durs ...time.Duration) (*Multi, error) {
+	bs := []*BPS{}
+	for _, d := range durs {
+		b, err := New(d)
+		if err != nil {
+			return nil, err
+		}
+		bs = append(bs, b)
+	}
+	r := &Multi{bs}
+	return r, nil
+}
+
+// Add adds i to each internal BPS.
+func (mw *Multi) Add(i int64) {
+	for _, b := range mw.bs {
+		b.Add(i)
+	}
+}
+
+// Rate returns a slice of rates, one for each BPS.
+func (mw *Multi) Rate() []float64 {
+	r := []float64{}
+	for _, b := range mw.bs {
+		r = append(r, b.Rate())
+	}
+	return r
+}