diff options
Diffstat (limited to 'common/math/integer.go')
| -rw-r--r-- | common/math/integer.go | 65 |
1 files changed, 59 insertions, 6 deletions
diff --git a/common/math/integer.go b/common/math/integer.go index 1689b6586..a3eeee27e 100644 --- a/common/math/integer.go +++ b/common/math/integer.go @@ -1,10 +1,63 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + package math -import gmath "math" +import "strconv" + +const ( + // Integer limit values. + MaxInt8 = 1<<7 - 1 + MinInt8 = -1 << 7 + MaxInt16 = 1<<15 - 1 + MinInt16 = -1 << 15 + MaxInt32 = 1<<31 - 1 + MinInt32 = -1 << 31 + MaxInt64 = 1<<63 - 1 + MinInt64 = -1 << 63 + MaxUint8 = 1<<8 - 1 + MaxUint16 = 1<<16 - 1 + MaxUint32 = 1<<32 - 1 + MaxUint64 = 1<<64 - 1 +) + +// ParseUint64 parses s as an integer in decimal or hexadecimal syntax. +// Leading zeros are accepted. The empty string parses as zero. +func ParseUint64(s string) (uint64, bool) { + if s == "" { + return 0, true + } + if len(s) >= 2 && (s[:2] == "0x" || s[:2] == "0X") { + v, err := strconv.ParseUint(s[2:], 16, 64) + return v, err == nil + } + v, err := strconv.ParseUint(s, 10, 64) + return v, err == nil +} + +// MustParseUint64 parses s as an integer and panics if the string is invalid. +func MustParseUint64(s string) uint64 { + v, ok := ParseUint64(s) + if !ok { + panic("invalid unsigned 64 bit integer: " + s) + } + return v +} -/* - * NOTE: The following methods need to be optimised using either bit checking or asm - */ +// NOTE: The following methods need to be optimised using either bit checking or asm // SafeSub returns subtraction result and whether overflow occurred. func SafeSub(x, y uint64) (uint64, bool) { @@ -13,7 +66,7 @@ func SafeSub(x, y uint64) (uint64, bool) { // SafeAdd returns the result and whether overflow occurred. func SafeAdd(x, y uint64) (uint64, bool) { - return x + y, y > gmath.MaxUint64-x + return x + y, y > MaxUint64-x } // SafeMul returns multiplication result and whether overflow occurred. @@ -21,5 +74,5 @@ func SafeMul(x, y uint64) (uint64, bool) { if x == 0 || y == 0 { return 0, false } - return x * y, y > gmath.MaxUint64/x + return x * y, y > MaxUint64/x } |