go-ethereum/accounts/abi/numbers.go
Felix Lange 5f7826270c all: unify big.Int zero checks, use common/math in more places (#3716)
* common/math: optimize PaddedBigBytes, use it more

name              old time/op    new time/op    delta
PaddedBigBytes-8    71.1ns ± 5%    46.1ns ± 1%  -35.15%  (p=0.000 n=20+19)

name              old alloc/op   new alloc/op   delta
PaddedBigBytes-8     48.0B ± 0%     32.0B ± 0%  -33.33%  (p=0.000 n=20+20)

* all: unify big.Int zero checks

Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.

eg templates:

    func before(x *big.Int) bool { return x.BitLen() == 0 }
    func after(x *big.Int) bool  { return x.Sign() == 0 }

    func before(x *big.Int) bool { return x.BitLen() > 0 }
    func after(x *big.Int) bool  { return x.Sign() != 0 }

    func before(x *big.Int) int { return x.Cmp(common.Big0) }
    func after(x *big.Int) int  { return x.Sign() }

* common/math, crypto/secp256k1: make ReadBits public in package math
2017-02-28 15:09:11 +01:00

86 lines
2.9 KiB
Go

// Copyright 2015 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 abi
import (
"math/big"
"reflect"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
)
var (
big_t = reflect.TypeOf(big.Int{})
ubig_t = reflect.TypeOf(big.Int{})
byte_t = reflect.TypeOf(byte(0))
byte_ts = reflect.TypeOf([]byte(nil))
uint_t = reflect.TypeOf(uint(0))
uint8_t = reflect.TypeOf(uint8(0))
uint16_t = reflect.TypeOf(uint16(0))
uint32_t = reflect.TypeOf(uint32(0))
uint64_t = reflect.TypeOf(uint64(0))
int_t = reflect.TypeOf(int(0))
int8_t = reflect.TypeOf(int8(0))
int16_t = reflect.TypeOf(int16(0))
int32_t = reflect.TypeOf(int32(0))
int64_t = reflect.TypeOf(int64(0))
hash_t = reflect.TypeOf(common.Hash{})
address_t = reflect.TypeOf(common.Address{})
uint_ts = reflect.TypeOf([]uint(nil))
uint8_ts = reflect.TypeOf([]uint8(nil))
uint16_ts = reflect.TypeOf([]uint16(nil))
uint32_ts = reflect.TypeOf([]uint32(nil))
uint64_ts = reflect.TypeOf([]uint64(nil))
ubig_ts = reflect.TypeOf([]*big.Int(nil))
int_ts = reflect.TypeOf([]int(nil))
int8_ts = reflect.TypeOf([]int8(nil))
int16_ts = reflect.TypeOf([]int16(nil))
int32_ts = reflect.TypeOf([]int32(nil))
int64_ts = reflect.TypeOf([]int64(nil))
big_ts = reflect.TypeOf([]*big.Int(nil))
)
// U256 converts a big Int into a 256bit EVM number.
func U256(n *big.Int) []byte {
return math.PaddedBigBytes(math.U256(n), 32)
}
// packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
func packNum(value reflect.Value) []byte {
switch kind := value.Kind(); kind {
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return U256(new(big.Int).SetUint64(value.Uint()))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return U256(big.NewInt(value.Int()))
case reflect.Ptr:
return U256(value.Interface().(*big.Int))
}
return nil
}
// checks whether the given reflect value is signed. This also works for slices with a number type
func isSigned(v reflect.Value) bool {
switch v.Type() {
case int_ts, int8_ts, int16_ts, int32_ts, int64_ts, int_t, int8_t, int16_t, int32_t, int64_t:
return true
}
return false
}