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safe_math.go
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/
safe_math.go
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// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package math
import (
"errors"
"math"
)
var (
errOverflow = errors.New("overflow occurred")
)
// Max64 ...
func Max64(a, b uint64) uint64 {
if a < b {
return b
}
return a
}
// Min64 ...
func Min64(a, b uint64) uint64 {
if a < b {
return a
}
return b
}
// Add64 ...
func Add64(a, b uint64) (uint64, error) {
if a > math.MaxUint64-b {
return 0, errOverflow
}
return a + b, nil
}
// Sub64 returns:
// 1) a - b
// 2) If there is underflow, an error
func Sub64(a, b uint64) (uint64, error) {
if a < b {
return 0, errOverflow
}
return a - b, nil
}
// Mul64 ...
func Mul64(a, b uint64) (uint64, error) {
if b != 0 && a > math.MaxUint64/b {
return 0, errOverflow
}
return a * b, nil
}
// Diff64 ...
func Diff64(a, b uint64) uint64 {
return Max64(a, b) - Min64(a, b)
}