def compute_digest_from_filelike_and_callback(filelike, h:_hashlib.HASH, bufferSize=STATIC_DEFAULT_BUFFER_SIZE, cback=None): """ Accessory method used to compute the digest of an input file-like object """ buf = filelike.read(bufferSize) while len(buf) > 0: h.update(buf) if cback: cback(buf) buf = filelike.read(bufferSize) return h.digest()
def calculate_hash2(self, part1: HASH) -> bytes:
"""Return the hash of the transaction, starting from a partial hash
The hash of the transactions is the `sha256(sha256(bytes(tx))`.
:param part1: A partial hash of the transaction, usually from `calculate_hash1`
:type part1: :py:class:`_hashlib.HASH`
:return: The transaction hash
:rtype: bytes
"""
part1.update(
self.nonce.to_bytes(self.HASH_NONCE_SIZE,
byteorder='big',
signed=False))
# SHA256D gets the hash in littlean format. Reverse the bytes to get the big-endian representation.
return hashlib.sha256(part1.digest()).digest()[::-1]
