def get_block_at_number(chain: BaseChain, at_block: Union[str, int]) -> BaseBlock:
# mypy doesn't have user defined type guards yet
# https://github.com/python/mypy/issues/5206
if is_integer(at_block) and at_block >= 0: # type: ignore
# optimization to avoid requesting block, then header, then block again
return chain.get_canonical_block_by_number(at_block)
else:
at_header = get_header(chain, at_block)
return chain.get_block_by_header(at_header)
def get_header(chain: BaseChain, at_block: Union[str, int]) -> BlockHeader:
if at_block == 'pending':
at_header = chain.header
elif at_block == 'latest':
at_header = chain.get_canonical_head()
elif at_block == 'earliest':
# TODO find if genesis block can be non-zero. Why does 'earliest' option even exist?
at_header = chain.get_canonical_block_by_number(0).header
# mypy doesn't have user defined type guards yet
# https://github.com/python/mypy/issues/5206
elif is_integer(at_block) and at_block >= 0: # type: ignore
at_header = chain.get_canonical_block_by_number(at_block).header
else:
raise TypeError("Unrecognized block reference: %r" % at_block)
return at_header
def __init__(self, chain: BaseChain, initial_tx_validation_block_number: int) -> None:
self.chain = chain
self._initial_tx_class = self._get_tx_class_for_block_number(
initial_tx_validation_block_number
)
self._ordered_tx_classes = [
vm_class.get_transaction_class()
for _, vm_class in chain.get_vm_configuration()
]
self._initial_tx_class_index = self._ordered_tx_classes.index(self._initial_tx_class)
def block_to_dict(
block: BaseBlock, chain: BaseChain,
include_transactions: bool) -> Dict[str, Union[str, List[str]]]:
header_dict = header_to_dict(block.header)
block_dict: Dict[str, Union[str, List[str]]] = dict(
header_dict,
totalDifficulty=hex(chain.get_score(block.hash)),
uncles=[encode_hex(uncle.hash) for uncle in block.uncles],
size=hex(len(rlp.encode(block))),
)
if include_transactions:
# block_dict['transactions'] = map(transaction_to_dict, block.transactions)
raise NotImplementedError(
"Cannot return transaction object with block, yet")
else:
block_dict['transactions'] = [
encode_hex(tx.hash) for tx in block.transactions
]
return block_dict
def account_db_at_block(chain: BaseChain,
at_block: Union[str, int],
read_only: bool = True) -> BaseAccountDB:
at_header = get_header(chain, at_block)
vm = chain.get_vm(at_header)
return vm.state.account_db