• Jeffrey Wilcke's avatar
    core, core/vm: implemented a generic environment (#3348) · 3fc7c978
    Jeffrey Wilcke authored
    Environment is now a struct (not an interface). This
    reduces a lot of tech-debt throughout the codebase where a virtual
    machine environment had to be implemented in order to test or run it.
    
    The new environment is suitable to be used en the json tests, core
    consensus and light client.
    3fc7c978
state_processor.go 5.57 KB
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package core

import (
	"math/big"

	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/ethereum/go-ethereum/logger"
	"github.com/ethereum/go-ethereum/logger/glog"
	"github.com/ethereum/go-ethereum/params"
)

var (
	big8  = big.NewInt(8)
	big32 = big.NewInt(32)
)

// StateProcessor is a basic Processor, which takes care of transitioning
// state from one point to another.
//
// StateProcessor implements Processor.
type StateProcessor struct {
	config *params.ChainConfig
	bc     *BlockChain
}

// NewStateProcessor initialises a new StateProcessor.
func NewStateProcessor(config *params.ChainConfig, bc *BlockChain) *StateProcessor {
	return &StateProcessor{
		config: config,
		bc:     bc,
	}
}

// Process processes the state changes according to the Ethereum rules by running
// the transaction messages using the statedb and applying any rewards to both
// the processor (coinbase) and any included uncles.
//
// Process returns the receipts and logs accumulated during the process and
// returns the amount of gas that was used in the process. If any of the
// transactions failed to execute due to insufficient gas it will return an error.
func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg vm.Config) (types.Receipts, vm.Logs, *big.Int, error) {
	var (
		receipts     types.Receipts
		totalUsedGas = big.NewInt(0)
		err          error
		header       = block.Header()
		allLogs      vm.Logs
		gp           = new(GasPool).AddGas(block.GasLimit())
	)
	// Mutate the the block and state according to any hard-fork specs
	if p.config.DAOForkSupport && p.config.DAOForkBlock != nil && p.config.DAOForkBlock.Cmp(block.Number()) == 0 {
		ApplyDAOHardFork(statedb)
	}
	// Iterate over and process the individual transactions
	for i, tx := range block.Transactions() {
		//fmt.Println("tx:", i)
		statedb.StartRecord(tx.Hash(), block.Hash(), i)
		receipt, logs, _, err := ApplyTransaction(p.config, p.bc, gp, statedb, header, tx, totalUsedGas, cfg)
		if err != nil {
			return nil, nil, nil, err
		}
		receipts = append(receipts, receipt)
		allLogs = append(allLogs, logs...)
	}
	AccumulateRewards(statedb, header, block.Uncles())

	return receipts, allLogs, totalUsedGas, err
}

// ApplyTransaction attempts to apply a transaction to the given state database
// and uses the input parameters for its environment.
//
// ApplyTransactions returns the generated receipts and vm logs during the
// execution of the state transition phase.
func ApplyTransaction(config *params.ChainConfig, bc *BlockChain, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *big.Int, cfg vm.Config) (*types.Receipt, vm.Logs, *big.Int, error) {
	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number))
	if err != nil {
		return nil, nil, nil, err
	}
	// Create a new context to be used in the EVM environment
	context := NewEVMContext(msg, header, bc)
	// Create a new environment which holds all relevant information
	// about the transaction and calling mechanisms.
	vmenv := vm.NewEnvironment(context, statedb, config, vm.Config{})
	// Apply the transaction to the current state (included in the env)
	_, gas, err := ApplyMessage(vmenv, msg, gp)
	if err != nil {
		return nil, nil, nil, err
	}

	// Update the state with pending changes
	usedGas.Add(usedGas, gas)
	// Create a new receipt for the transaction, storing the intermediate root and gas used by the tx
	// based on the eip phase, we're passing wether the root touch-delete accounts.
	receipt := types.NewReceipt(statedb.IntermediateRoot(config.IsEIP158(header.Number)).Bytes(), usedGas)
	receipt.TxHash = tx.Hash()
	receipt.GasUsed = new(big.Int).Set(gas)
	// if the transaction created a contract, store the creation address in the receipt.
	if msg.To() == nil {
		receipt.ContractAddress = crypto.CreateAddress(vmenv.Context.Origin, tx.Nonce())
	}

	// Set the receipt logs and create a bloom for filtering
	receipt.Logs = statedb.GetLogs(tx.Hash())
	receipt.Bloom = types.CreateBloom(types.Receipts{receipt})

	glog.V(logger.Debug).Infoln(receipt)

	return receipt, receipt.Logs, gas, err
}

// AccumulateRewards credits the coinbase of the given block with the
// mining reward. The total reward consists of the static block reward
// and rewards for included uncles. The coinbase of each uncle block is
// also rewarded.
func AccumulateRewards(statedb *state.StateDB, header *types.Header, uncles []*types.Header) {
	reward := new(big.Int).Set(BlockReward)
	r := new(big.Int)
	for _, uncle := range uncles {
		r.Add(uncle.Number, big8)
		r.Sub(r, header.Number)
		r.Mul(r, BlockReward)
		r.Div(r, big8)
		statedb.AddBalance(uncle.Coinbase, r)

		r.Div(BlockReward, big32)
		reward.Add(reward, r)
	}
	statedb.AddBalance(header.Coinbase, reward)
}