ring.go

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package stats

// RingInt64 Ring of int64 values
// Not thread safe
type RingInt64 struct {
	position int
	values   []int64
}

// NewRingInt64 create ring
func NewRingInt64(capacity int) *RingInt64 {
	return &RingInt64{values: make([]int64, 0, capacity)}
}

// Add add value into ring
func (ri *RingInt64) Add(val int64) {
	if len(ri.values) == cap(ri.values) {
		ri.values[ri.position] = val
		ri.position = (ri.position + 1) % cap(ri.values)
	} else {
		ri.values = append(ri.values, val)
	}
}

// Values return values in ring
func (ri *RingInt64) Values() (values []int64) {
	values = make([]int64, len(ri.values))
	for i := 0; i < len(ri.values); i++ {
		values[i] = ri.values[(ri.position+i)%cap(ri.values)]
	}
	return values
}