github.com/ethereumproject/go-ethereum@v5.5.2+incompatible/core/vm_env.go (about)

     1  // Copyright 2014 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 core
    18  
    19  import (
    20  	"math/big"
    21  
    22  	"github.com/ethereumproject/go-ethereum/common"
    23  	"github.com/ethereumproject/go-ethereum/core/state"
    24  	"github.com/ethereumproject/go-ethereum/core/types"
    25  	"github.com/ethereumproject/go-ethereum/core/vm"
    26  )
    27  
    28  // GetHashFn returns a function for which the VM env can query block hashes through
    29  // up to the limit defined by the Yellow Paper and uses the given block chain
    30  // to query for information.
    31  func GetHashFn(ref common.Hash, chain *BlockChain) func(n uint64) common.Hash {
    32  	return func(n uint64) common.Hash {
    33  		for block := chain.GetBlock(ref); block != nil; block = chain.GetBlock(block.ParentHash()) {
    34  			if block.NumberU64() == n {
    35  				return block.Hash()
    36  			}
    37  		}
    38  
    39  		return common.Hash{}
    40  	}
    41  }
    42  
    43  type VMEnv struct {
    44  	chainConfig *ChainConfig   // Chain configuration
    45  	state       *state.StateDB // State to use for executing
    46  	evm         *vm.EVM        // The Ethereum Virtual Machine
    47  	depth       int            // Current execution depth
    48  	msg         Message        // Message appliod
    49  
    50  	header    *types.Header            // Header information
    51  	chain     *BlockChain              // Blockchain handle
    52  	getHashFn func(uint64) common.Hash // getHashFn callback is used to retrieve block hashes
    53  }
    54  
    55  func NewEnv(state *state.StateDB, chainConfig *ChainConfig, chain *BlockChain, msg Message, header *types.Header) *VMEnv {
    56  	env := &VMEnv{
    57  		chainConfig: chainConfig,
    58  		chain:       chain,
    59  		state:       state,
    60  		header:      header,
    61  		msg:         msg,
    62  		getHashFn:   GetHashFn(header.ParentHash, chain),
    63  	}
    64  
    65  	env.evm = vm.New(env)
    66  	return env
    67  }
    68  
    69  func (self *VMEnv) RuleSet() vm.RuleSet      { return self.chainConfig }
    70  func (self *VMEnv) Vm() vm.Vm                { return self.evm }
    71  func (self *VMEnv) Origin() common.Address   { f, _ := self.msg.From(); return f }
    72  func (self *VMEnv) BlockNumber() *big.Int    { return self.header.Number }
    73  func (self *VMEnv) Coinbase() common.Address { return self.header.Coinbase }
    74  func (self *VMEnv) Time() *big.Int           { return self.header.Time }
    75  func (self *VMEnv) Difficulty() *big.Int     { return self.header.Difficulty }
    76  func (self *VMEnv) GasLimit() *big.Int       { return self.header.GasLimit }
    77  func (self *VMEnv) Value() *big.Int          { return self.msg.Value() }
    78  func (self *VMEnv) Db() vm.Database          { return self.state }
    79  func (self *VMEnv) Depth() int               { return self.depth }
    80  func (self *VMEnv) SetDepth(i int)           { self.depth = i }
    81  func (self *VMEnv) GetHash(n uint64) common.Hash {
    82  	return self.getHashFn(n)
    83  }
    84  
    85  func (self *VMEnv) AddLog(log *vm.Log) {
    86  	self.state.AddLog(*log)
    87  }
    88  func (self *VMEnv) CanTransfer(from common.Address, balance *big.Int) bool {
    89  	return self.state.GetBalance(from).Cmp(balance) >= 0
    90  }
    91  
    92  func (self *VMEnv) SnapshotDatabase() int {
    93  	return self.state.Snapshot()
    94  }
    95  
    96  func (self *VMEnv) RevertToSnapshot(snapshot int) {
    97  	self.state.RevertToSnapshot(snapshot)
    98  }
    99  
   100  func (self *VMEnv) Transfer(from, to vm.Account, amount *big.Int) {
   101  	Transfer(from, to, amount)
   102  }
   103  
   104  func (self *VMEnv) Call(me vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
   105  	return Call(self, me, addr, data, gas, price, value)
   106  }
   107  func (self *VMEnv) CallCode(me vm.ContractRef, addr common.Address, data []byte, gas, price, value *big.Int) ([]byte, error) {
   108  	return CallCode(self, me, addr, data, gas, price, value)
   109  }
   110  
   111  func (self *VMEnv) DelegateCall(me vm.ContractRef, addr common.Address, data []byte, gas, price *big.Int) ([]byte, error) {
   112  	return DelegateCall(self, me, addr, data, gas, price)
   113  }
   114  
   115  func (self *VMEnv) Create(me vm.ContractRef, data []byte, gas, price, value *big.Int) ([]byte, common.Address, error) {
   116  	return Create(self, me, data, gas, price, value)
   117  }