syncthing/vendor/github.com/cznic/mathutil/rat.go
2016-06-02 13:53:30 +02:00

28 lines
636 B
Go

// Copyright (c) 2014 The mathutil Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package mathutil
// QCmpUint32 compares a/b and c/d and returns:
//
// -1 if a/b < c/d
// 0 if a/b == c/d
// +1 if a/b > c/d
//
func QCmpUint32(a, b, c, d uint32) int {
switch x, y := uint64(a)*uint64(d), uint64(b)*uint64(c); {
case x < y:
return -1
case x == y:
return 0
default: // x > y
return 1
}
}
// QScaleUint32 returns a such that a/b >= c/d.
func QScaleUint32(b, c, d uint32) (a uint64) {
return 1 + (uint64(b)*uint64(c))/uint64(d)
}