// ValidateState validates the various changes that happen after a state
// transition, such as amount of used gas, the receipt roots and the state root
// itself. ValidateState returns a database batch if the validation was a succes
// otherwise nil and an error is returned.
func (v *BlockValidator) ValidateState(block, parent *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas *big.Int) (err error) {
header := block.Header()
if block.GasUsed().Cmp(usedGas) != 0 {
return ValidationError(fmt.Sprintf("gas used error (%v / %v)", block.GasUsed(), usedGas))
}
// Validate the received block's bloom with the one derived from the generated receipts.
// For valid blocks this should always validate to true.
rbloom := types.CreateBloom(receipts)
if rbloom != header.Bloom {
return fmt.Errorf("unable to replicate block's bloom=%x", rbloom)
}
// Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]]))
receiptSha := types.DeriveSha(receipts)
if receiptSha != header.ReceiptHash {
return fmt.Errorf("invalid receipt root hash. received=%x calculated=%x", header.ReceiptHash, receiptSha)
}
// Validate the state root against the received state root and throw
// an error if they don't match.
if root := statedb.IntermediateRoot(); header.Root != root {
return fmt.Errorf("invalid merkle root: header=%x computed=%x", header.Root, root)
}
return nil
}
// ApplyTransaction attemps 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(bc *BlockChain, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *big.Int) (*types.Receipt, vm.Logs, *big.Int, error) {
_, gas, err := ApplyMessage(NewEnv(statedb, bc, tx, header), tx, gp)
if err != nil {
return nil, nil, nil, err
}
// Update the state with pending changes
usedGas.Add(usedGas, gas)
receipt := types.NewReceipt(statedb.IntermediateRoot().Bytes(), usedGas)
receipt.TxHash = tx.Hash()
receipt.GasUsed = new(big.Int).Set(gas)
if MessageCreatesContract(tx) {
from, _ := tx.From()
receipt.ContractAddress = crypto.CreateAddress(from, tx.Nonce())
}
logs := statedb.GetLogs(tx.Hash())
receipt.Logs = logs
receipt.Bloom = types.CreateBloom(types.Receipts{receipt})
glog.V(logger.Debug).Infoln(receipt)
return receipt, logs, gas, err
}
func makeHeader(parent *types.Block, state *state.StateDB) *types.Header {
var time *big.Int
if parent.Time() == nil {
time = big.NewInt(10)
} else {
time = new(big.Int).Add(parent.Time(), big.NewInt(10)) // block time is fixed at 10 seconds
}
return &types.Header{
Root: state.IntermediateRoot(),
ParentHash: parent.Hash(),
Coinbase: parent.Coinbase(),
Difficulty: CalcDifficulty(time.Uint64(), new(big.Int).Sub(time, big.NewInt(10)).Uint64(), parent.Number(), parent.Difficulty()),
GasLimit: CalcGasLimit(parent),
GasUsed: new(big.Int),
Number: new(big.Int).Add(parent.Number(), common.Big1),
Time: time,
}
}