def serialize(self):
return b''.join((
self.prev_hash,
pack_le_uint32(self.prev_idx),
pack_varbytes(self.script),
pack_le_uint32(self.sequence),
))
def serialize(self):
return b''.join((
self.keyimage,
self.ringsize,
pack_varbytes(self.script),
pack_le_uint32(self.sequence),
))
def serialize(self):
return b''.join(
(pack_le_int32(self.version), pack_varint(len(self.inputs)),
b''.join(tx_in.serialize() for tx_in in self.inputs),
pack_varint(len(self.outputs)),
b''.join(tx_out.serialize() for tx_out in self.outputs),
pack_le_uint32(self.locktime)))
def serialize(self):
assert len(self.merkleRootMNList) == 32
res = (
pack_le_uint16(self.version) + # version
pack_le_uint32(self.height) + # height
self.merkleRootMNList # merkleRootMNList
)
if self.version > 1:
assert len(self.merkleRootQuorums) == 32
res += self.merkleRootQuorums # merkleRootQuorums
return res
def push_data(cls, data):
'''Returns the opcodes to push the data on the stack.'''
assert isinstance(data, (bytes, bytearray))
n = len(data)
if n < OpCodes.OP_PUSHDATA1:
return bytes([n]) + data
if n < 256:
return bytes([OpCodes.OP_PUSHDATA1, n]) + data
if n < 65536:
return bytes([OpCodes.OP_PUSHDATA2]) + pack_le_uint16(n) + data
return bytes([OpCodes.OP_PUSHDATA4]) + pack_le_uint32(n) + data
def lookup_hashX(tx_hash, tx_idx):
idx_packed = pack_le_uint32(tx_idx)
# Key: b'h' + compressed_tx_hash + tx_idx + tx_num
# Value: hashX
prefix = b'h' + tx_hash[:4] + idx_packed
# Find which entry, if any, the TX_HASH matches.
for db_key, hashX in self.utxo_db.iterator(prefix=prefix):
tx_num_packed = db_key[-5:]
tx_num, = unpack_le_uint64(tx_num_packed + bytes(3))
hash, _height = self.fs_tx_hash(tx_num)
if hash == tx_hash:
return hashX, idx_packed + tx_num_packed
return None, None
def serialize(self):
nLocktime = pack_le_uint32(self.locktime)
txins = (pack_varint(len(self.inputs)) +
b''.join(tx_in.serialize() for tx_in in self.inputs))
txouts = (pack_varint(len(self.outputs)) +
b''.join(tx_out.serialize() for tx_out in self.outputs))
if self.tx_type:
uVersion = pack_le_uint16(self.version)
uTxType = pack_le_uint16(self.tx_type)
vExtra = self._serialize_extra_payload()
return uVersion + uTxType + txins + txouts + nLocktime + vExtra
else:
nVersion = pack_le_int32(self.version)
return nVersion + txins + txouts + nLocktime
def spend_utxo(self, tx_hash, tx_idx):
'''Spend a UTXO and return the 33-byte value.
If the UTXO is not in the cache it must be on disk. We store
all UTXOs so not finding one indicates a logic error or DB
corruption.
'''
# Fast track is it being in the cache
idx_packed = pack_le_uint32(tx_idx)
cache_value = self.utxo_cache.pop(tx_hash + idx_packed, None)
if cache_value:
return cache_value
# Spend it from the DB.
# Key: b'h' + compressed_tx_hash + tx_idx + tx_num
# Value: hashX
prefix = b'h' + tx_hash[:4] + idx_packed
candidates = {
db_key: hashX
for db_key, hashX in self.db.utxo_db.iterator(prefix=prefix)
}
for hdb_key, hashX in candidates.items():
tx_num_packed = hdb_key[-5:]
if len(candidates) > 1:
tx_num, = unpack_le_uint64(tx_num_packed + bytes(3))
hash, _height = self.db.fs_tx_hash(tx_num)
if hash != tx_hash:
assert hash is not None # Should always be found
continue
# Key: b'u' + address_hashX + tx_idx + tx_num
# Value: the UTXO value as a 64-bit unsigned integer
udb_key = b'u' + hashX + hdb_key[-9:]
utxo_value_packed = self.db.utxo_db.get(udb_key)
if utxo_value_packed:
# Remove both entries for this UTXO
self.db_deletes.append(hdb_key)
self.db_deletes.append(udb_key)
return hashX + tx_num_packed + utxo_value_packed
raise ChainError('UTXO {} / {:,d} not found in "h" table'.format(
hash_to_hex_str(tx_hash), tx_idx))
def backup_txs(self, txs, is_unspendable):
undo_info = self.db.read_undo_info(self.height)
if undo_info is None:
raise ChainError(
'no undo information found for height {:,d}'.format(
self.height))
# Use local vars for speed in the loops
put_utxo = self.utxo_cache.__setitem__
spend_utxo = self.spend_utxo
script_hashX = self.coin.hashX_from_script
add_touched = self.touched.add
undo_entry_len = 13 + HASHX_LEN
# Restore coins that had been spent
# (may include coins made then spent in this block)
n = 0
for tx, tx_hash in txs:
for txin in tx.inputs:
if txin.is_generation():
continue
undo_item = undo_info[n:n + undo_entry_len]
put_utxo(txin.prev_hash + pack_le_uint32(txin.prev_idx),
undo_item)
add_touched(undo_item[:-13])
n += undo_entry_len
assert n == len(undo_info)
# Remove tx outputs made in this block, by spending them.
for tx, tx_hash in txs:
for idx, txout in enumerate(tx.outputs):
# Spend the TX outputs. Be careful with unspendable
# outputs - we didn't save those in the first place.
if is_unspendable(txout.pk_script):
continue
# Get the hashX
hashX = script_hashX(txout.script)
cache_value = spend_utxo(tx_hash, idx)
add_touched(cache_value[:-13])
self.tx_count -= len(txs)
def _read_tx_parts(self, produce_hash=True):
start = self.cursor
version = self._read_le_int32()
inputs = self._read_inputs()
outputs = self._read_outputs()
locktime = self._read_le_uint32()
expiry = self._read_le_uint32()
end_prefix = self.cursor
witness = self._read_witness(len(inputs))
if produce_hash:
# TxSerializeNoWitness << 16 == 0x10000
no_witness_header = pack_le_uint32(0x10000 | (version & 0xffff))
prefix_tx = no_witness_header + self.binary[start + 4:end_prefix]
tx_hash = self.blake256(prefix_tx)
else:
tx_hash = None
return TxDcr(version, inputs, outputs, locktime, expiry,
witness), tx_hash, self.cursor - start
def backup_txs(self, txs, is_unspendable):
# Prevout values, in order down the block (coinbase first if present)
# undo_info is in reverse block order
undo_info = self.db.read_undo_info(self.height)
if undo_info is None:
raise ChainError(
'no undo information found for height {:,d}'.format(
self.height))
n = len(undo_info)
# Use local vars for speed in the loops
put_utxo = self.utxo_cache.__setitem__
spend_utxo = self.spend_utxo
script_hashX = self.coin.hashX_from_script
touched = self.touched
undo_entry_len = 13 + HASHX_LEN
for tx, tx_hash in reversed(txs):
for idx, txout in enumerate(tx.outputs):
# Spend the TX outputs. Be careful with unspendable
# outputs - we didn't save those in the first place.
if is_unspendable(txout.pk_script):
continue
# Get the hashX
hashX = script_hashX(txout.pk_script)
cache_value = spend_utxo(tx_hash, idx)
touched.add(cache_value[:-13])
# Restore the inputs
for txin in reversed(tx.inputs):
if txin.is_generation():
continue
n -= undo_entry_len
undo_item = undo_info[n:n + undo_entry_len]
put_utxo(txin.prev_hash + pack_le_uint32(txin.prev_idx),
undo_item)
touched.add(undo_item[:-13])
assert n == 0
self.tx_count -= len(txs)
def serialize(self):
assert len(self.hash) == 32
return (
self.hash + # hash
pack_le_uint32(self.index) # index
)
