initial import

core/collection/ring.go

@@ -0,0 +1,35 @@
+package collection
+
+type Ring struct {
+	elements []interface{}
+	index    int
+}
+
+func NewRing(n int) *Ring {
+	return &Ring{
+		elements: make([]interface{}, n),
+	}
+}
+
+func (r *Ring) Add(v interface{}) {
+	r.elements[r.index%len(r.elements)] = v
+	r.index++
+}
+
+func (r *Ring) Take() []interface{} {
+	var size int
+	var start int
+	if r.index > len(r.elements) {
+		size = len(r.elements)
+		start = r.index % len(r.elements)
+	} else {
+		size = r.index
+	}
+
+	elements := make([]interface{}, size)
+	for i := 0; i < size; i++ {
+		elements[i] = r.elements[(start+i)%len(r.elements)]
+	}
+
+	return elements
+}