github.com/sberex/go-sberex@v1.8.2-0.20181113200658-ed96ac38f7d7/accounts/abi/pack.go (about)

     1  // This file is part of the go-sberex library. The go-sberex library is 
     2  // free software: you can redistribute it and/or modify it under the terms 
     3  // of the GNU Lesser General Public License as published by the Free 
     4  // Software Foundation, either version 3 of the License, or (at your option)
     5  // any later version.
     6  //
     7  // The go-sberex library is distributed in the hope that it will be useful, 
     8  // but WITHOUT ANY WARRANTY; without even the implied warranty of
     9  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 
    10  // General Public License <http://www.gnu.org/licenses/> for more details.
    11  
    12  package abi
    13  
    14  import (
    15  	"math/big"
    16  	"reflect"
    17  
    18  	"github.com/Sberex/go-sberex/common"
    19  	"github.com/Sberex/go-sberex/common/math"
    20  )
    21  
    22  // packBytesSlice packs the given bytes as [L, V] as the canonical representation
    23  // bytes slice
    24  func packBytesSlice(bytes []byte, l int) []byte {
    25  	len := packNum(reflect.ValueOf(l))
    26  	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
    27  }
    28  
    29  // packElement packs the given reflect value according to the abi specification in
    30  // t.
    31  func packElement(t Type, reflectValue reflect.Value) []byte {
    32  	switch t.T {
    33  	case IntTy, UintTy:
    34  		return packNum(reflectValue)
    35  	case StringTy:
    36  		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
    37  	case AddressTy:
    38  		if reflectValue.Kind() == reflect.Array {
    39  			reflectValue = mustArrayToByteSlice(reflectValue)
    40  		}
    41  
    42  		return common.LeftPadBytes(reflectValue.Bytes(), 32)
    43  	case BoolTy:
    44  		if reflectValue.Bool() {
    45  			return math.PaddedBigBytes(common.Big1, 32)
    46  		}
    47  		return math.PaddedBigBytes(common.Big0, 32)
    48  	case BytesTy:
    49  		if reflectValue.Kind() == reflect.Array {
    50  			reflectValue = mustArrayToByteSlice(reflectValue)
    51  		}
    52  		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
    53  	case FixedBytesTy, FunctionTy:
    54  		if reflectValue.Kind() == reflect.Array {
    55  			reflectValue = mustArrayToByteSlice(reflectValue)
    56  		}
    57  		return common.RightPadBytes(reflectValue.Bytes(), 32)
    58  	default:
    59  		panic("abi: fatal error")
    60  	}
    61  }
    62  
    63  // packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
    64  func packNum(value reflect.Value) []byte {
    65  	switch kind := value.Kind(); kind {
    66  	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
    67  		return U256(new(big.Int).SetUint64(value.Uint()))
    68  	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
    69  		return U256(big.NewInt(value.Int()))
    70  	case reflect.Ptr:
    71  		return U256(value.Interface().(*big.Int))
    72  	default:
    73  		panic("abi: fatal error")
    74  	}
    75  
    76  }