def iter_all(self, tx_storage: 'TransactionStorage') -> Iterator[Transaction]:
bfs = BFSWalk(tx_storage, is_dag_verifications=True, is_left_to_right=False)
for tx in bfs.run(self.iter(tx_storage), skip_root=False):
assert isinstance(tx, Transaction)
if tx.get_metadata().first_block is not None:
bfs.skip_neighbors(tx)
else:
yield tx
def add_voided_by(self, tx: Transaction, voided_hash: bytes) -> bool:
""" Add a hash from `meta.voided_by` and its descendants (both from verification DAG
and funds tree).
"""
assert tx.hash is not None
assert tx.storage is not None
meta = tx.get_metadata()
if meta.voided_by and voided_hash in meta.voided_by:
return False
self.log.debug('add_voided_by',
tx=tx.hash_hex,
voided_hash=voided_hash.hex())
is_dag_verifications = True
if meta.voided_by and bool(self.soft_voided_tx_ids & meta.voided_by):
# If tx is soft voided, we can only walk through the DAG of funds.
is_dag_verifications = False
from hathor.transaction.storage.traversal import BFSWalk
bfs = BFSWalk(tx.storage,
is_dag_funds=True,
is_dag_verifications=is_dag_verifications,
is_left_to_right=True)
check_list: List[Transaction] = []
for tx2 in bfs.run(tx, skip_root=False):
assert tx2.storage is not None
assert tx2.hash is not None
meta2 = tx2.get_metadata()
if tx2.is_block:
assert isinstance(tx2, Block)
self.consensus.block_algorithm.mark_as_voided(tx2)
assert not meta2.voided_by or voided_hash not in meta2.voided_by
if tx2.hash != tx.hash and meta2.conflict_with and not meta2.voided_by:
check_list.extend(
cast(Transaction, tx2.storage.get_transaction(h))
for h in meta2.conflict_with)
if meta2.voided_by:
meta2.voided_by.add(voided_hash)
else:
meta2.voided_by = {voided_hash}
if meta2.conflict_with:
assert isinstance(tx2, Transaction)
self.mark_as_voided(tx2)
# All voided transactions with conflicts must have their accumulated weight calculated.
tx2.update_accumulated_weight(save_file=False)
tx2.storage.save_transaction(tx2, only_metadata=True)
tx2.storage.del_from_indexes(tx2, relax_assert=True)
self.assert_valid_consensus(tx2)
for tx2 in check_list:
self.check_conflicts(tx2)
return True
def update_accumulated_weight(
self,
*,
stop_value: float = inf,
save_file: bool = True) -> TransactionMetadata:
"""Calculates the tx's accumulated weight and update its metadata.
It starts at the current transaction and does a BFS to the tips. In the
end, updates the accumulated weight on metadata
It stops calculating the accumulated weight when the value passes the `stop_value`.
This may be used when the accumulated weight is being calculated to be compared to another value.
In this case, we may stop calculating when we are already higher than `stop_value`.
:param: stop_value: Threshold to stop calculating the accumulated weight.
:return: transaction metadata
:rtype: :py:class:`hathor.transaction.TransactionMetadata`
"""
assert self.storage is not None
metadata = self.get_metadata()
if metadata.accumulated_weight > stop_value:
return metadata
accumulated_weight = self.weight
# TODO Another optimization is that, when we calculate the acc weight of a transaction, we
# also partially calculate the acc weight of its descendants. If it were a DFS, when returning
# to a vertex, the acc weight calculated would be <= the real acc weight. So, we might store it
# as a pre-calculated value. Then, during the next DFS, if `cur + tx.acc_weight > stop_value`,
# we might stop and avoid some visits. Question: how would we do it in the BFS?
# TODO We can walk by the blocks first, because they have higher weight and this may
# reduce the number of visits in the BFS. We need to specially handle when a transaction is not
# directly verified by a block.
from hathor.transaction.storage.traversal import BFSWalk
bfs_walk = BFSWalk(self.storage,
is_dag_funds=True,
is_dag_verifications=True,
is_left_to_right=True)
for tx in bfs_walk.run(self, skip_root=True):
accumulated_weight = sum_weights(accumulated_weight, tx.weight)
if accumulated_weight > stop_value:
break
metadata.accumulated_weight = accumulated_weight
if save_file:
self.storage.save_transaction(self, only_metadata=True)
return metadata
def remove_voided_by(self, tx: Transaction, voided_hash: bytes) -> bool:
""" Remove a hash from `meta.voided_by` and its descendants (both from verification DAG
and funds tree).
"""
from hathor.transaction.storage.traversal import BFSWalk
assert tx.hash is not None
assert tx.storage is not None
meta = tx.get_metadata()
if not meta.voided_by:
return False
if voided_hash not in meta.voided_by:
return False
self.log.debug('remove_voided_by',
tx=tx.hash_hex,
voided_hash=voided_hash.hex())
bfs = BFSWalk(tx.storage,
is_dag_funds=True,
is_dag_verifications=True,
is_left_to_right=True)
check_list: List[BaseTransaction] = []
for tx2 in bfs.run(tx, skip_root=False):
assert tx2.storage is not None
meta2 = tx2.get_metadata()
if not (meta2.voided_by and voided_hash in meta2.voided_by):
bfs.skip_neighbors(tx2)
continue
if meta2.voided_by:
meta2.voided_by.discard(voided_hash)
if meta2.voided_by == {tx2.hash}:
check_list.append(tx2)
if not meta2.voided_by:
meta2.voided_by = None
tx.storage.add_to_indexes(tx2)
tx2.storage.save_transaction(tx2, only_metadata=True)
self.assert_valid_consensus(tx2)
from hathor.transaction import Transaction
for tx2 in check_list:
if not tx2.is_block:
assert isinstance(tx2, Transaction)
self.check_conflicts(tx2)
return True
def add_voided_by(self, tx: 'Transaction', voided_hash: bytes) -> bool:
""" Add a hash from `meta.voided_by` and its descendants (both from verification DAG
and funds tree).
"""
assert tx.hash is not None
assert tx.storage is not None
meta = tx.get_metadata()
if meta.voided_by and voided_hash in meta.voided_by:
return False
self.log.debug('add_voided_by tx={} voided_hash={}'.format(tx.hash.hex(), voided_hash.hex()))
from hathor.transaction.storage.traversal import BFSWalk
bfs = BFSWalk(tx.storage, is_dag_funds=True, is_dag_verifications=True, is_left_to_right=True)
check_list: List['Transaction'] = []
for tx2 in bfs.run(tx, skip_root=False):
assert tx2.storage is not None
assert tx2.hash is not None
meta2 = tx2.get_metadata()
if tx2.is_block:
assert isinstance(tx2, Block)
self.consensus.block_algorithm.mark_as_voided(tx2)
assert not meta2.voided_by or voided_hash not in meta2.voided_by
if tx2.hash != tx.hash and meta2.conflict_with and not meta2.voided_by:
check_list.extend(tx2.storage.get_transaction(h) for h in meta2.conflict_with)
if meta2.voided_by:
meta2.voided_by.add(voided_hash)
else:
meta2.voided_by = {voided_hash}
if meta2.conflict_with:
meta2.voided_by.add(tx2.hash)
# All voided transactions with conflicts must have their accumulated weight calculated.
tx2.update_accumulated_weight(save_file=False)
tx2.storage.save_transaction(tx2, only_metadata=True)
tx2.storage._del_from_cache(tx2, relax_assert=True) # XXX: accessing private method
for tx2 in check_list:
self.check_conflicts(tx2)
return True
def remove_first_block_markers(self, block: 'Block') -> None:
""" Remove all `meta.first_block` pointing to this block.
"""
assert block.storage is not None
storage = block.storage
from hathor.transaction.storage.traversal import BFSWalk
bfs = BFSWalk(storage, is_dag_verifications=True, is_left_to_right=False)
for tx in bfs.run(block, skip_root=True):
if tx.is_block:
bfs.skip_neighbors(tx)
continue
meta = tx.get_metadata()
if meta.first_block != block.hash:
bfs.skip_neighbors(tx)
continue
meta.first_block = None
storage.save_transaction(tx, only_metadata=True)
def _score_block_dfs(self, block: BaseTransaction, used: Set[bytes],
mark_as_best_chain: bool,
newest_timestamp: int) -> float:
""" Internal method to run a DFS. It is used by `calculate_score()`.
"""
assert block.storage is not None
assert block.hash is not None
assert block.is_block
storage = block.storage
from hathor.transaction import Block
score = block.weight
for parent in block.get_parents():
if parent.is_block:
assert isinstance(parent, Block)
if parent.timestamp <= newest_timestamp:
meta = parent.get_metadata()
x = meta.score
else:
x = self._score_block_dfs(parent, used, mark_as_best_chain,
newest_timestamp)
score = sum_weights(score, x)
else:
from hathor.transaction.storage.traversal import BFSWalk
bfs = BFSWalk(storage,
is_dag_verifications=True,
is_left_to_right=False)
for tx in bfs.run(parent, skip_root=False):
assert tx.hash is not None
assert not tx.is_block
if tx.hash in used:
bfs.skip_neighbors(tx)
continue
used.add(tx.hash)
meta = tx.get_metadata()
if meta.first_block:
first_block = storage.get_transaction(meta.first_block)
if first_block.timestamp <= newest_timestamp:
bfs.skip_neighbors(tx)
continue
if mark_as_best_chain:
assert meta.first_block is None
meta.first_block = block.hash
storage.save_transaction(tx, only_metadata=True)
score = sum_weights(score, tx.weight)
# Always save the score when it is calculated.
meta = block.get_metadata()
if not meta.score:
meta.score = score
storage.save_transaction(block, only_metadata=True)
else:
# The score of a block is immutable since the sub-DAG behind it is immutable as well.
# Thus, if we have already calculated it, we just check the consistency of the calculation.
# Unfortunately we may have to calculate it more than once when a new block arrives in a side
# side because the `first_block` points only to the best chain.
assert abs(meta.score - score) < 1e-10, \
'hash={} meta.score={} score={}'.format(block.hash.hex(), meta.score, score)
return score