def parse_transactions(self, limit=0):
"""
Parse raw transactions from Block, if transaction data is available in txs_data attribute. Creates
Transaction objects in Block.transactions list
:param limit: Maximum number of transactions to parse
:return:
"""
n = 0
while self.txs_data and (limit == 0 or n < limit) and len(
self.transactions) < self.tx_count:
t = Transaction.parse_bytesio(
self.txs_data, strict=False,
network=self.network) # , check_size=False
self.transactions.append(t)
n += 1
def from_raw(cls,
raw,
block_hash=None,
height=None,
parse_transactions=False,
limit=0,
network=DEFAULT_NETWORK):
"""
Create Block object from raw serialized block in bytes.
Get genesis block:
>>> from bitcoinlib.services.services import Service
>>> srv = Service()
>>> b = srv.getblock(0)
>>> b.block_hash.hex()
'000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
:param raw: Raw serialize block
:type raw: bytes
:param block_hash: Specify block hash if known to verify raw block. Value error will be raised if calculated block hash is different than specified.
:type block_hash: bytes
:param height: Specify height if known. Will be derived from coinbase transaction if not provided.
:type height: int
:param parse_transactions: Indicate if transactions in raw block need to be parsed and converted to Transaction objects. Default is False
:type parse_transactions: bool
:param limit: Maximum number of transactions to parse. Default is 0: parse all transactions. Only used if parse_transaction is set to True
:type limit: int
:param network: Name of network
:type network: str
:return Block:
"""
block_hash_calc = double_sha256(raw[:80])[::-1]
if not block_hash:
block_hash = block_hash_calc
elif block_hash != block_hash_calc:
raise ValueError(
"Provided block hash does not correspond to calculated block hash %s"
% block_hash_calc.hex())
version = raw[0:4][::-1]
prev_block = raw[4:36][::-1]
merkle_root = raw[36:68][::-1]
time = raw[68:72][::-1]
bits = raw[72:76][::-1]
nonce = raw[76:80][::-1]
tx_count, size = varbyteint_to_int(raw[80:89])
txs_data = BytesIO(raw[80 + size:])
# Parse coinbase transaction so we can extract extra information
# transactions = [Transaction.parse(txs_data, network=network)]
# txs_data = BytesIO(txs_data[transactions[0].size:])
# block_txs_data = txs_data.read()
txs_data_size = txs_data.seek(0, 2)
txs_data.seek(0)
transactions = []
while parse_transactions and txs_data and txs_data.tell(
) < txs_data_size:
if limit != 0 and len(transactions) >= limit:
break
t = Transaction.parse_bytesio(txs_data, strict=False)
transactions.append(t)
# t = transaction_deserialize(txs_data, network=network, check_size=False)
# transactions.append(t)
# txs_data = txs_data[t.size:]
# TODO: verify transactions, need input value from previous txs
# if verify and not t.verify():
# raise ValueError("Could not verify transaction %s in block %s" % (t.txid, block_hash))
if parse_transactions and limit == 0 and tx_count != len(transactions):
raise ValueError(
"Number of found transactions %d is not equal to expected number %d"
% (len(transactions), tx_count))
block = cls(block_hash,
version,
prev_block,
merkle_root,
time,
bits,
nonce,
transactions,
height,
network=network)
block.txs_data = txs_data
block.tx_count = tx_count
return block
