Method ValidateState

core/block_validator.go:78–101

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 success otherwise nil and an error is returned.

(block, parent *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas uint64)

// itself. ValidateState returns a database batch if the validation was a success
// otherwise nil and an error is returned.
func (v *BlockValidator) ValidateState(block, parent *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas uint64) error {
	// this is a copy of the block header.
	header := block.Header()
	if block.GasUsed() != usedGas {
		return fmt.Errorf("invalid gas used (remote: %d local: %d)", 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.LogsBloom {
		return fmt.Errorf("invalid bloom (remote: %x  local: %x)", header.LogsBloom, rbloom)
	}
	// Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]]))
	receiptSha := types.DeriveSha(receipts)
	if receiptSha != header.ReceiptsRoot {
		return fmt.Errorf("invalid receipt root hash (remote: %x local: %x)", header.ReceiptsRoot, receiptSha)
	}
	// Validate the state root against the received state root and throw
	// an error if they don't match.
	if root := statedb.IntermediateRoot(true); header.StateRoot != root {
		return fmt.Errorf("invalid merkle root (remote: %x local: %x)", header.StateRoot, root)
	}
	return nil
}

// CalcGasLimit computes the gas limit of the next block after parent.
// This is miner strategy, not consensus protocol.