def test_correct_nonce():
timestamp = datetime.utcfromtimestamp(0)
block_one = Block(
index=0,
block_hash="",
size=0,
header=Header(
timestamp=timestamp,
transaction_merkle_root="",
nonce=100,
previous_hash="",
difficulty=4,
version=1,
),
transaction_count=0,
transactions=[],
)
previous_hash = Verification.hash_block_header(block_one.header)
open_transactions = [
SignedRawTransaction(
details=Details(
sender="test2",
recipient="test",
amount=2.5,
nonce=0,
timestamp=timestamp,
public_key="pub_key",
),
signature="sig",
)
]
block_header = Header(
version=1,
difficulty=4,
timestamp=datetime.utcfromtimestamp(1),
transaction_merkle_root=get_merkle_root(open_transactions),
previous_hash=previous_hash,
nonce=0,
)
block_header = Verification.proof_of_work(block_header)
block_two = Block(
index=1,
block_hash="",
size=0,
header=block_header,
transaction_count=len(open_transactions),
transactions=[
Verification.hash_transaction(t) for t in open_transactions
],
)
assert Verification.valid_nonce(block_two.header)
def mine_block(
self,
address: Optional[str] = None,
difficulty: Optional[int] = None,
version: Optional[int] = None,
) -> Optional[Block]:
"""
The current node runs the mining protocol, and depending on the difficulty, this
could take a lot of processing power.
Once the nonce is discovered, or "mined", the reward transaction is created.
Then all of the open transactions are validated and verified, ensuring that
the senders in all of the transactions have enough coin to conduct the transaction.
Once the transactions are validated, the reward block is added to the list of
open transactions. This is because Mining transactions do not need to be validated
since they are created by the node itself.
The block is then added directy to the node's chain and the open_transactions is
cleared and ready for a new block to be mined
Finally, the new block is broadcasted to all connected nodes.
"""
if not address:
address = self.address
if not address:
return None
difficulty = difficulty if difficulty is not None else self.difficulty
version = version if version is not None else self.version
last_block = self.last_block
transaction_merkle_root = get_merkle_root(
[tx.signed_transaction for tx in self.get_open_transactions])
previous_hash = Verification.hash_block_header(last_block.header)
block_header = Header(
version=version,
difficulty=difficulty,
timestamp=datetime.utcnow(),
transaction_merkle_root=transaction_merkle_root,
previous_hash=previous_hash,
nonce=0,
)
# We run the PoW algorithm to get the next nonce and return an updated block_header
block_header = Verification.proof_of_work(block_header)
# Create the transaction that will be rewarded to the miners for their work
# The sender is "0" or "Mining" to signify that this node has mined a new coin.
reward_signed = SignedRawTransaction(
details=Details(
sender="0",
recipient=address,
nonce=0,
amount=MINING_REWARD,
timestamp=datetime.utcnow(),
public_key="coinbase",
),
signature="coinbase",
)
reward_transaction = FinalTransaction(
transaction_hash=Verification.hash_transaction(reward_signed),
transaction_id=Verification.hash_transaction(reward_signed),
signed_transaction=reward_signed,
)
# Copy transactions instead of manipulating the original open_transactions list
# This ensures that if for some reason the mining should fail,
# we don't have the reward transaction stored in the pending transactions
copied_open_transactions = self.get_open_transactions
for tx in copied_open_transactions:
if not Wallet.verify_transaction(tx.signed_transaction,
self.get_last_tx_nonce,
exclude_from_open=True):
return None
FinalTransaction.SaveTransaction(self.data_location,
reward_transaction, "mining")
self.__broadcast_transaction(reward_transaction.signed_transaction,
"mining")
for t in copied_open_transactions:
self.__broadcast_transaction(t.signed_transaction, "confirmed")
copied_open_transactions.append(reward_transaction)
block = Block(
index=self.next_index,
header=block_header,
block_hash=Verification.hash_block_header(block_header),
size=len(str(block_header)),
transaction_count=len(copied_open_transactions),
transactions=[
t.transaction_hash for t in copied_open_transactions
],
)
# Add the block to the node's chain
self.add_block_to_chain(block)
# Reset the open list of transactions
logger.info("Moving open transaction to confirmed storage at %s",
self.data_location)
FinalTransaction.MoveOpenTransactions(self.data_location)
self.__open_transactions = []
self.save_data()
self.__broadcast_block(block)
return block