def get_ops(cls, script):
ops = []
# The unpacks or script[n] below throw on truncated scripts
try:
n = 0
while n < len(script):
op = script[n]
n += 1
if op <= OpCodes.OP_PUSHDATA4:
# Raw bytes follow
if op < OpCodes.OP_PUSHDATA1:
dlen = op
elif op == OpCodes.OP_PUSHDATA1:
dlen = script[n]
n += 1
elif op == OpCodes.OP_PUSHDATA2:
dlen, = unpack_le_uint16_from(script[n: n + 2])
n += 2
else:
dlen, = unpack_le_uint32_from(script[n: n + 4])
n += 4
if n + dlen > len(script):
raise IndexError
op = (op, script[n:n + dlen])
n += dlen
ops.append(op)
except Exception:
# Truncated script; e.g. tx_hash
# ebc9fa1196a59e192352d76c0f6e73167046b9d37b8302b6bb6968dfd279b767
raise ScriptError('truncated script')
return ops
async def raw_blocks(self, hex_hashes):
'''Return the raw binary blocks with the given hex hashes.'''
params_iterable = ((h, False) for h in hex_hashes)
blocks = await self._send_vector('getblock', params_iterable)
raw_blocks = []
valid_tx_tree = {}
for block in blocks:
# Convert to bytes from hex
raw_block = hex_to_bytes(block)
raw_blocks.append(raw_block)
# Check if previous block is valid
prev = self.prev_hex_hash(raw_block)
votebits = unpack_le_uint16_from(raw_block[100:102])[0]
valid_tx_tree[prev] = self.is_valid_tx_tree(votebits)
processed_raw_blocks = []
for hash, raw_block in zip(hex_hashes, raw_blocks):
if hash in valid_tx_tree:
is_valid = valid_tx_tree[hash]
else:
# Do something complicated to figure out if this block is valid
header = await self._send_single('getblockheader', (hash, ))
if 'nextblockhash' not in header:
raise DaemonError(f'Could not find next block for {hash}')
next_hash = header['nextblockhash']
next_header = await self._send_single('getblockheader',
(next_hash, ))
is_valid = self.is_valid_tx_tree(next_header['votebits'])
if is_valid:
processed_raw_blocks.append(raw_block)
else:
# If this block is invalid remove the normal transactions
self.logger.info(f'block {hash} is invalidated')
processed_raw_blocks.append(self.strip_tx_tree(raw_block))
return processed_raw_blocks
def _read_le_uint16(self):
result, = unpack_le_uint16_from(self.binary, self.cursor)
self.cursor += 2
return result
