github.com/kapoio/go-kapoio@v1.9.7/accounts/abi/pack.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package abi
    18  
    19  import (
    20  	"math/big"
    21  	"reflect"
    22  
    23  	"github.com/ethereum/go-ethereum/common"
    24  	"github.com/ethereum/go-ethereum/common/math"
    25  )
    26  
    27  // packBytesSlice packs the given bytes as [L, V] as the canonical representation
    28  // bytes slice
    29  func packBytesSlice(bytes []byte, l int) []byte {
    30  	len := packNum(reflect.ValueOf(l))
    31  	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
    32  }
    33  
    34  // packElement packs the given reflect value according to the abi specification in
    35  // t.
    36  func packElement(t Type, reflectValue reflect.Value) []byte {
    37  	switch t.T {
    38  	case IntTy, UintTy:
    39  		return packNum(reflectValue)
    40  	case StringTy:
    41  		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
    42  	case AddressTy:
    43  		if reflectValue.Kind() == reflect.Array {
    44  			reflectValue = mustArrayToByteSlice(reflectValue)
    45  		}
    46  
    47  		return common.LeftPadBytes(reflectValue.Bytes(), 32)
    48  	case BoolTy:
    49  		if reflectValue.Bool() {
    50  			return math.PaddedBigBytes(common.Big1, 32)
    51  		}
    52  		return math.PaddedBigBytes(common.Big0, 32)
    53  	case BytesTy:
    54  		if reflectValue.Kind() == reflect.Array {
    55  			reflectValue = mustArrayToByteSlice(reflectValue)
    56  		}
    57  		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
    58  	case FixedBytesTy, FunctionTy:
    59  		if reflectValue.Kind() == reflect.Array {
    60  			reflectValue = mustArrayToByteSlice(reflectValue)
    61  		}
    62  		return common.RightPadBytes(reflectValue.Bytes(), 32)
    63  	default:
    64  		panic("abi: fatal error")
    65  	}
    66  }
    67  
    68  // packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
    69  func packNum(value reflect.Value) []byte {
    70  	switch kind := value.Kind(); kind {
    71  	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
    72  		return U256(new(big.Int).SetUint64(value.Uint()))
    73  	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
    74  		return U256(big.NewInt(value.Int()))
    75  	case reflect.Ptr:
    76  		return U256(value.Interface().(*big.Int))
    77  	default:
    78  		panic("abi: fatal error")
    79  	}
    80  
    81  }