status-go/vendor/github.com/ethereum/go-ethereum/accounts/abi/pack.go

86 lines
3.0 KiB
Go

// Copyright 2016 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 (
"errors"
"fmt"
"math/big"
"reflect"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
)
// packBytesSlice packs the given bytes as [L, V] as the canonical representation
// bytes slice.
func packBytesSlice(bytes []byte, l int) []byte {
len := packNum(reflect.ValueOf(l))
return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
}
// packElement packs the given reflect value according to the abi specification in
// t.
func packElement(t Type, reflectValue reflect.Value) ([]byte, error) {
switch t.T {
case IntTy, UintTy:
return packNum(reflectValue), nil
case StringTy:
return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len()), nil
case AddressTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
return common.LeftPadBytes(reflectValue.Bytes(), 32), nil
case BoolTy:
if reflectValue.Bool() {
return math.PaddedBigBytes(common.Big1, 32), nil
}
return math.PaddedBigBytes(common.Big0, 32), nil
case BytesTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
if reflectValue.Type() != reflect.TypeOf([]byte{}) {
return []byte{}, errors.New("Bytes type is neither slice nor array")
}
return packBytesSlice(reflectValue.Bytes(), reflectValue.Len()), nil
case FixedBytesTy, FunctionTy:
if reflectValue.Kind() == reflect.Array {
reflectValue = mustArrayToByteSlice(reflectValue)
}
return common.RightPadBytes(reflectValue.Bytes(), 32), nil
default:
return []byte{}, fmt.Errorf("Could not pack element, unknown type: %v", t.T)
}
}
// 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 math.U256Bytes(new(big.Int).SetUint64(value.Uint()))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return math.U256Bytes(big.NewInt(value.Int()))
case reflect.Ptr:
return math.U256Bytes(new(big.Int).Set(value.Interface().(*big.Int)))
default:
panic("abi: fatal error")
}
}