bps/bytes.go

package bps

// from https://github.com/dustin/go-humanize/
//
// Copyright (c) 2005-2008  Dustin Sallings <dustin@spy.net>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// <http://www.opensource.org/licenses/mit-license.php>

import (
	"fmt"
	"math"
)

func logn(n, b float64) float64 {
	return math.Log(n) / math.Log(b)
}

func humanateBytes(s uint64, base float64, sizes []string) string {
	if s < 10 {
		return fmt.Sprintf("%dB", s)
	}
	e := math.Floor(logn(float64(s), base))
	suffix := sizes[int(e)]
	val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
	f := "%.0f%s"
	if val < 10 {
		f = "%.1f%s"
	}

	return fmt.Sprintf(f, val, suffix)
}

// Bytes produces a human readable representation of an SI size.
//
// Bytes(82854982) -> 83MB
func human(s uint64) string {
	sizes := []string{"B", "kB", "MB", "GB", "TB", "PB", "EB"}
	return humanateBytes(s, 1000, sizes)
}