github.com/ontio/ontology@v1.14.4/vm/evm/runtime/env.go (about)

     1  // Copyright (C) 2021 The Ontology Authors
     2  // Copyright 2015 The go-ethereum Authors
     3  // This file is part of the go-ethereum library.
     4  //
     5  // The go-ethereum library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Lesser General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // The go-ethereum library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  // GNU Lesser General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Lesser General Public License
    16  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package runtime
    19  
    20  import (
    21  	"math/big"
    22  
    23  	"github.com/ethereum/go-ethereum/common"
    24  	"github.com/ontio/ontology/vm/evm"
    25  )
    26  
    27  func NewEnv(cfg *Config) *evm.EVM {
    28  	txContext := evm.TxContext{
    29  		Origin:   cfg.Origin,
    30  		GasPrice: cfg.GasPrice,
    31  	}
    32  	blockContext := evm.BlockContext{
    33  		CanTransfer: CanTransfer,
    34  		Transfer:    Transfer,
    35  		GetHash:     cfg.GetHashFn,
    36  		Coinbase:    cfg.Coinbase,
    37  		BlockNumber: cfg.BlockNumber,
    38  		Time:        cfg.Time,
    39  		Difficulty:  cfg.Difficulty,
    40  		GasLimit:    cfg.GasLimit,
    41  	}
    42  
    43  	return evm.NewEVM(blockContext, txContext, cfg.State, cfg.ChainConfig, cfg.EVMConfig)
    44  }
    45  
    46  // CanTransfer checks whether there are enough funds in the address' account to make a transfer.
    47  // This does not take the necessary gas in to account to make the transfer valid.
    48  func CanTransfer(db evm.StateDB, addr common.Address, amount *big.Int) bool {
    49  	return db.GetBalance(addr).Cmp(amount) >= 0
    50  }
    51  
    52  // Transfer subtracts amount from sender and adds amount to recipient using the given Db
    53  func Transfer(db evm.StateDB, sender, recipient common.Address, amount *big.Int) {
    54  	db.SubBalance(sender, amount)
    55  	db.AddBalance(recipient, amount)
    56  	evm.MakeOngTransferLog(db, sender, recipient, amount)
    57  }