def to_dict(self):
"""Transform the Block to a Python dictionary.
Returns:
dict: The Block as a dict.
Raises:
OperationError: If the Block doesn't contain any transactions.
"""
if len(self.transactions) == 0:
raise OperationError('Empty block creation is not allowed')
block = {
'timestamp': self.timestamp,
'transactions': [tx.to_dict() for tx in self.transactions],
'node_pubkey': self.node_pubkey,
'voters': self.voters,
}
block_serialized = serialize(block)
block_id = hash_data(block_serialized)
return {
'id': block_id,
'block': block,
'signature': self.signature,
}
def validate(self, bigchain):
"""Validate a block.
Args:
bigchain (Bigchain): an instantiated bigchaindb.Bigchain object.
Returns:
block (Block): The block as a `Block` object if it is valid.
Else it raises an appropriate exception describing
the reason of invalidity.
Raises:
OperationError: if a non-federation node signed the block.
"""
# First, make sure this node hasn't already voted on this block
if bigchain.has_previous_vote(self.id, self.voters):
return self
# Check if the block was created by a federation node
possible_voters = (bigchain.nodes_except_me + [bigchain.me])
if self.node_pubkey not in possible_voters:
raise OperationError('Only federation nodes can create blocks')
if not self.is_signature_valid():
raise InvalidSignature('Block signature invalid')
# Finally: Tentative assumption that every blockchain will want to
# validate all transactions in each block
for tx in self.transactions:
# NOTE: If a transaction is not valid, `is_valid` will throw an
# an exception and block validation will be canceled.
bigchain.validate_transaction(tx)
return self
def run_upsert_validator_new(args, bigchain):
"""Initiates an election to add/update/remove a validator to an existing BigchainDB network
:param args: dict
args = {
'public_key': the public key of the proposed peer, (str)
'power': the proposed validator power for the new peer, (str)
'node_id': the node_id of the new peer (str)
'sk': the path to the private key of the node calling the election (str)
}
:param bigchain: an instance of BigchainDB
:return: election_id (tx_id)
:raises: OperationError if the write transaction fails for any reason
"""
new_validator = {
'public_key': args.public_key,
'power': args.power,
'node_id': args.node_id
}
key = load_node_key(args.sk)
voters = ValidatorElection.recipients(bigchain)
election = ValidatorElection.generate([key.public_key], voters,
new_validator,
None).sign([key.private_key])
election.validate(bigchain)
resp = bigchain.write_transaction(election, 'broadcast_tx_commit')
if resp == (202, ''):
return election.id
else:
raise OperationError('Failed to commit election')
def to_dict(self):
if len(self.transactions) == 0:
raise OperationError('Empty block creation is not allowed')
block = {
'timestamp': self.timestamp,
'transactions': [tx.to_dict() for tx in self.transactions],
'node_pubkey': self.node_pubkey,
'voters': self.voters,
}
block_serialized = serialize(block)
block_id = hash_data(block_serialized)
return {
'id': block_id,
'block': block,
'signature': self.signature,
}
def _validate_block(self, bigchain):
"""Validate the Block without validating the transactions.
Args:
bigchain (:class:`~bigchaindb.Bigchain`): An instantiated Bigchain
object.
Raises:
OperationError: If a non-federation node signed the Block.
InvalidSignature: If a Block's signature is invalid.
"""
# Check if the block was created by a federation node
possible_voters = (bigchain.nodes_except_me + [bigchain.me])
if self.node_pubkey not in possible_voters:
raise OperationError('Only federation nodes can create blocks')
# Check that the signature is valid
if not self.is_signature_valid():
raise InvalidSignature('Invalid block signature')
def run_upsert_validator_approve(args, bigchain):
"""Approve an election to add/update/remove a validator to an existing BigchainDB network
:param args: dict
args = {
'election_id': the election_id of the election (str)
'sk': the path to the private key of the signer (str)
}
:param bigchain: an instance of BigchainDB
:return: a success message
:raises: OperationError if the write transaction fails for any reason
"""
key = load_node_key(args.sk)
tx = bigchain.get_transaction(args.election_id)
voting_powers = [
v.amount for v in tx.outputs if key.public_key in v.public_keys
]
if len(voting_powers) > 0:
voting_power = voting_powers[0]
else:
raise KeypairMismatchException(
'The key you provided does not match any of the eligible voters in this election.'
)
inputs = [i for i in tx.to_inputs() if key.public_key in i.owners_before]
approval = ValidatorElectionVote.generate(
inputs, [([key.public_key], voting_power)],
tx.id).sign([key.private_key])
approval.validate(bigchain)
resp = bigchain.write_transaction(approval, 'broadcast_tx_commit')
if resp == (202, ''):
print('Your vote has been submitted.')
return approval.id
else:
raise OperationError('Failed to vote for election')