github.com/ethereumproject/go-ethereum@v5.5.2+incompatible/accounts/abi/packing.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/ethereumproject/go-ethereum/common"
    24  )
    25  
    26  // packBytesSlice packs the given bytes as [L, V] as the canonical representation
    27  // bytes slice
    28  func packBytesSlice(bytes []byte, l int) []byte {
    29  	len := packNum(reflect.ValueOf(l))
    30  	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
    31  }
    32  
    33  // packElement packs the given reflect value according to the abi specification in
    34  // t.
    35  func packElement(t Type, reflectValue reflect.Value) []byte {
    36  	switch t.T {
    37  	case IntTy, UintTy:
    38  		return packNum(reflectValue)
    39  	case StringTy:
    40  		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
    41  	case AddressTy:
    42  		if reflectValue.Kind() == reflect.Array {
    43  			reflectValue = mustArrayToByteSlice(reflectValue)
    44  		}
    45  
    46  		return common.LeftPadBytes(reflectValue.Bytes(), 32)
    47  	case BoolTy:
    48  		if reflectValue.Bool() {
    49  			return common.LeftPadBytes(common.Big1.Bytes(), 32)
    50  		} else {
    51  			return common.LeftPadBytes(new(big.Int).Bytes(), 32)
    52  		}
    53  	case BytesTy:
    54  		if reflectValue.Kind() == reflect.Array {
    55  			reflectValue = mustArrayToByteSlice(reflectValue)
    56  		}
    57  		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
    58  	case FixedBytesTy:
    59  		if reflectValue.Kind() == reflect.Array {
    60  			reflectValue = mustArrayToByteSlice(reflectValue)
    61  		}
    62  
    63  		return common.RightPadBytes(reflectValue.Bytes(), 32)
    64  	}
    65  	panic("abi: fatal error")
    66  }