quorum/core/state_processor.go

// 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"
	"math/big"
	"strings"

	"github.com/ethereum/go-ethereum/accounts/abi"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/consensus"
	"github.com/ethereum/go-ethereum/consensus/misc"
	"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/log"
	"github.com/ethereum/go-ethereum/params"
)

// 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 // Chain configuration options
	bc     *BlockChain         // Canonical block chain
	engine consensus.Engine    // Consensus engine used for block rewards
}

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

// 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, privateState *state.StateDB, cfg vm.Config) (types.Receipts, types.Receipts, []*types.Log, uint64, error) {

	var (
		receipts types.Receipts
		usedGas  = new(uint64)
		header   = block.Header()
		allLogs  []*types.Log
		gp       = new(GasPool).AddGas(block.GasLimit())

		privateReceipts types.Receipts
	)
	// Mutate 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 {
		misc.ApplyDAOHardFork(statedb)
	}
	// Iterate over and process the individual transactions
	for i, tx := range block.Transactions() {
		statedb.Prepare(tx.Hash(), block.Hash(), i)
		privateState.Prepare(tx.Hash(), block.Hash(), i)

		receipt, privateReceipt, err := ApplyTransaction(p.config, p.bc, nil, gp, statedb, privateState, header, tx, usedGas, cfg)
		if err != nil {
			return nil, nil, nil, 0, err
		}
		receipts = append(receipts, receipt)
		allLogs = append(allLogs, receipt.Logs...)

		// if the private receipt is nil this means the tx was public
		// and we do not need to apply the additional logic.
		if privateReceipt != nil {
			privateReceipts = append(privateReceipts, privateReceipt)
			allLogs = append(allLogs, privateReceipt.Logs...)
		}
	}

	if p.config.BlockReward != nil {
		CallBlockReward(statedb, p.bc, header, p.config)
	}

	// Finalize the block, applying any consensus engine specific extras (e.g. block rewards)
	p.engine.Finalize(p.bc, header, statedb, block.Transactions(), block.Uncles())

	return receipts, privateReceipts, allLogs, *usedGas, nil
}

// ApplyTransaction attempts to apply a transaction to the given state database
// and uses the input parameters for its environment. It returns the receipt
// for the transaction, gas used and an error if the transaction failed,
// indicating the block was invalid.
func ApplyTransaction(config *params.ChainConfig, bc *BlockChain, author *common.Address, gp *GasPool, statedb, privateState *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config) (*types.Receipt, *types.Receipt, error) {
	if !config.IsQuorum || !tx.IsPrivate() {
		privateState = statedb
	}

	if config.IsQuorum && tx.GasPrice() != nil && tx.GasPrice().Cmp(common.Big0) > 0 {
		return nil, nil, ErrInvalidGasPrice
	}

	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number))
	if err != nil {
		return nil, nil, err
	}
	// Create a new context to be used in the EVM environment
	context := NewEVMContext(msg, header, bc, author)
	// Create a new environment which holds all relevant information
	// about the transaction and calling mechanisms.
	vmenv := vm.NewEVM(context, statedb, privateState, config, cfg)

	// Apply the transaction to the current state (included in the env)
	_, gas, failed, err := ApplyMessage(vmenv, msg, gp)
	if err != nil {
		return nil, nil, err
	}
	// Update the state with pending changes
	var root []byte
	if config.IsByzantium(header.Number) {
		statedb.Finalise(true)
	} else {
		root = statedb.IntermediateRoot(config.IsEIP158(header.Number)).Bytes()
	}
	*usedGas += gas

	// If this is a private transaction, the public receipt should always
	// indicate success.
	publicFailed := !(config.IsQuorum && tx.IsPrivate()) && failed

	// 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(root, publicFailed, *usedGas)
	receipt.TxHash = tx.Hash()
	receipt.GasUsed = 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})
	receipt.BlockHash = statedb.BlockHash()
	receipt.BlockNumber = header.Number
	receipt.TransactionIndex = uint(statedb.TxIndex())

	var privateReceipt *types.Receipt
	if config.IsQuorum && tx.IsPrivate() {
		var privateRoot []byte
		if config.IsByzantium(header.Number) {
			privateState.Finalise(true)
		} else {
			privateRoot = privateState.IntermediateRoot(config.IsEIP158(header.Number)).Bytes()
		}
		privateReceipt = types.NewReceipt(privateRoot, failed, *usedGas)
		privateReceipt.TxHash = tx.Hash()
		privateReceipt.GasUsed = gas
		if msg.To() == nil {
			privateReceipt.ContractAddress = crypto.CreateAddress(vmenv.Context.Origin, tx.Nonce())
		}

		privateReceipt.Logs = privateState.GetLogs(tx.Hash())
		privateReceipt.Bloom = types.CreateBloom(types.Receipts{privateReceipt})
	}

	return receipt, privateReceipt, err
}

func CallBlockReward(state *state.StateDB, bc *BlockChain, header *types.Header, config *params.ChainConfig) {
	var from = common.HexToAddress("0x0")
	var to common.Address = config.BlockReward.Contract
	var bigZero = big.NewInt(0)
	var gas uint64 = math.MaxUint64
	log.Trace("Call to block reward contract", "address", to)
	abi, _ := abi.JSON(strings.NewReader(`[{"type":"function","name":"reward","constant":false,"inputs":[{"name":"benefactors","type":"address[]"},{"name":"kind","type":"uint16[]"}],"outputs":[{"name":"receivers","type":"address[]"},{"name":"values","type":"uint256[]"}]}]`))
	calldata, _ := abi.Pack("reward", [0]common.Address{}, [0]uint16{})
	msg := types.NewMessage(from, &to, 0, bigZero, gas, bigZero, calldata, false)
	evmContext := NewEVMContext(msg, header, bc, nil)
	// Create a new environment which holds all relevant information
	// about the transaction and calling mechanisms.
	evm := vm.NewEVM(evmContext, state, state, config, vm.Config{})
	gaspool := new(GasPool).AddGas(gas)
	ret, _, _, _ := NewStateTransition(evm, msg, gaspool).TransitionDb()

	receivers := make([]common.Address, 0, 1)
	values := make([]*big.Int, 0, 1)
	_ = abi.Unpack(&[]interface{}{&receivers, &values}, "reward", ret)

	state.SetNonce(from, 0)
	for i, receiver := range receivers {
		log.Trace("Minting coins", "receiver", receiver, "values", *values[i])
		state.AddBalance(receiver, values[i])
	}
}