github.com/n1ghtfa1l/go-vnt@v0.6.4-alpha.6/core/wavm/utils/decode.go (about)

     1  // Copyright 2019 The go-vnt Authors
     2  // This file is part of the go-vnt library.
     3  //
     4  // The go-vnt 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-vnt 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-vnt library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package utils
    18  
    19  import (
    20  	"bytes"
    21  
    22  	"github.com/vntchain/go-vnt/core/vm"
    23  	"github.com/vntchain/go-vnt/core/wavm/contract"
    24  	"github.com/vntchain/go-vnt/rlp"
    25  )
    26  
    27  func DecodeContractCode(input []byte) (contract.WasmCode, []byte, error) {
    28  	magic, _ := ReadMagic(input)
    29  	if magic != MAGIC {
    30  		return contract.WasmCode{}, nil, vm.ErrMagicNumberMismatch
    31  	}
    32  	input = input[4:]
    33  	buf := bytes.NewReader(input)
    34  	cps := []byte{}
    35  	err := rlp.Decode(buf, &cps)
    36  	if err != nil {
    37  		return contract.WasmCode{}, nil, err
    38  	}
    39  	decom, err := DeCompress(cps)
    40  	if err != nil {
    41  		return contract.WasmCode{}, nil, err
    42  	}
    43  	dec := contract.WasmCode{}
    44  	err = rlp.Decode(bytes.NewReader(decom), &dec)
    45  	if err != nil {
    46  		return contract.WasmCode{}, nil, err
    47  	}
    48  	return dec, input[int(buf.Size())-buf.Len():], nil
    49  }