lbry-sdk/torba/baseledger.py
2018-08-16 00:56:46 -04:00

397 lines
15 KiB
Python

import os
import logging
from binascii import hexlify, unhexlify
from typing import Dict, Type, Iterable
from operator import itemgetter
from collections import namedtuple
from twisted.internet import defer
from torba import baseaccount
from torba import basenetwork
from torba import basetransaction
from torba.basedatabase import BaseDatabase
from torba.baseheader import BaseHeaders
from torba.coinselection import CoinSelector
from torba.constants import COIN, NULL_HASH32
from torba.stream import StreamController
from torba.hash import hash160, double_sha256, sha256, Base58
log = logging.getLogger(__name__)
LedgerType = Type['BaseLedger']
class LedgerRegistry(type):
ledgers: Dict[str, LedgerType] = {}
def __new__(mcs, name, bases, attrs):
cls: LedgerType = super().__new__(mcs, name, bases, attrs)
if not (name == 'BaseLedger' and not bases):
ledger_id = cls.get_id()
assert ledger_id not in mcs.ledgers,\
'Ledger with id "{}" already registered.'.format(ledger_id)
mcs.ledgers[ledger_id] = cls
return cls
@classmethod
def get_ledger_class(mcs, ledger_id: str) -> LedgerType:
return mcs.ledgers[ledger_id]
class TransactionEvent(namedtuple('TransactionEvent', ('address', 'tx', 'height', 'is_verified'))):
pass
class BaseLedger(metaclass=LedgerRegistry):
name: str
symbol: str
network_name: str
database_class = BaseDatabase
account_class = baseaccount.BaseAccount
network_class = basenetwork.BaseNetwork
transaction_class = basetransaction.BaseTransaction
headers_class: Type[BaseHeaders]
pubkey_address_prefix: bytes
script_address_prefix: bytes
extended_public_key_prefix: bytes
extended_private_key_prefix: bytes
default_fee_per_byte = 10
def __init__(self, config=None):
self.config = config or {}
self.db: BaseDatabase = self.config.get('db') or self.database_class(
os.path.join(self.path, "blockchain.db")
)
self.headers: BaseHeaders = self.config.get('headers') or self.headers_class(
os.path.join(self.path, "headers")
)
self.network = self.config.get('network') or self.network_class(self)
self.network.on_header.listen(self.receive_header)
self.network.on_status.listen(self.receive_status)
self.accounts = []
self.fee_per_byte: int = self.config.get('fee_per_byte', self.default_fee_per_byte)
self._on_transaction_controller = StreamController()
self.on_transaction = self._on_transaction_controller.stream
self.on_transaction.listen(
lambda e: log.info(
'(%s) on_transaction: address=%s, height=%s, is_verified=%s, tx.id=%s',
self.get_id(), e.address, e.height, e.is_verified, e.tx.id
)
)
self._on_header_controller = StreamController()
self.on_header = self._on_header_controller.stream
self.on_header.listen(
lambda change: log.info(
'%s: added %s header blocks, final height %s',
self.get_id(), change, self.headers.height
)
)
self._transaction_processing_locks = {}
self._utxo_reservation_lock = defer.DeferredLock()
self._header_processing_lock = defer.DeferredLock()
@classmethod
def get_id(cls):
return '{}_{}'.format(cls.symbol.lower(), cls.network_name.lower())
@classmethod
def hash160_to_address(cls, h160):
raw_address = cls.pubkey_address_prefix + h160
return Base58.encode(bytearray(raw_address + double_sha256(raw_address)[0:4]))
@staticmethod
def address_to_hash160(address):
return Base58.decode(address)[1:21]
@classmethod
def public_key_to_address(cls, public_key):
return cls.hash160_to_address(hash160(public_key))
@staticmethod
def private_key_to_wif(private_key):
return b'\x1c' + private_key + b'\x01'
@property
def path(self):
return os.path.join(self.config['data_path'], self.get_id())
@defer.inlineCallbacks
def add_account(self, account: baseaccount.BaseAccount) -> defer.Deferred:
self.accounts.append(account)
if self.network.is_connected:
yield self.update_account(account)
@defer.inlineCallbacks
def get_transaction(self, txhash):
raw, _, _ = yield self.db.get_transaction(txhash)
if raw is not None:
defer.returnValue(self.transaction_class(raw))
@defer.inlineCallbacks
def get_private_key_for_address(self, address):
match = yield self.db.get_address(address)
if match:
for account in self.accounts:
if match['account'] == account.public_key.address:
defer.returnValue(account.get_private_key(match['chain'], match['position']))
@defer.inlineCallbacks
def get_effective_amount_estimators(self, funding_accounts: Iterable[baseaccount.BaseAccount]):
estimators = []
for account in funding_accounts:
utxos = yield account.get_unspent_outputs()
for utxo in utxos:
estimators.append(utxo.get_estimator(self))
defer.returnValue(estimators)
@defer.inlineCallbacks
def get_spendable_utxos(self, amount: int, funding_accounts):
yield self._utxo_reservation_lock.acquire()
try:
txos = yield self.get_effective_amount_estimators(funding_accounts)
selector = CoinSelector(
txos, amount,
self.transaction_class.output_class.pay_pubkey_hash(COIN, NULL_HASH32).get_fee(self)
)
spendables = selector.select()
if spendables:
yield self.reserve_outputs(s.txo for s in spendables)
except Exception:
log.exception('Failed to get spendable utxos:')
raise
finally:
self._utxo_reservation_lock.release()
defer.returnValue(spendables)
def reserve_outputs(self, txos):
return self.db.reserve_outputs(txos)
def release_outputs(self, txos):
return self.db.release_outputs(txos)
@defer.inlineCallbacks
def get_local_status(self, address):
address_details = yield self.db.get_address(address)
history = address_details['history'] or ''
h = sha256(history.encode())
defer.returnValue(hexlify(h))
@defer.inlineCallbacks
def get_local_history(self, address):
address_details = yield self.db.get_address(address)
history = address_details['history'] or ''
parts = history.split(':')[:-1]
defer.returnValue(list(zip(parts[0::2], map(int, parts[1::2]))))
@staticmethod
def get_root_of_merkle_tree(branches, branch_positions, working_branch):
for i, branch in enumerate(branches):
other_branch = unhexlify(branch)[::-1]
other_branch_on_left = bool((branch_positions >> i) & 1)
if other_branch_on_left:
combined = other_branch + working_branch
else:
combined = working_branch + other_branch
working_branch = double_sha256(combined)
return hexlify(working_branch[::-1])
@defer.inlineCallbacks
def is_valid_transaction(self, tx, height):
height <= len(self.headers) or defer.returnValue(False)
merkle = yield self.network.get_merkle(tx.id, height)
merkle_root = self.get_root_of_merkle_tree(merkle['merkle'], merkle['pos'], tx.hash)
header = self.headers[height]
defer.returnValue(merkle_root == header['merkle_root'])
@defer.inlineCallbacks
def start(self):
if not os.path.exists(self.path):
os.mkdir(self.path)
yield defer.gatherResults([
self.db.open(),
self.headers.open()
])
first_connection = self.network.on_connected.first
self.network.start()
yield first_connection
yield self.update_headers()
yield self.network.subscribe_headers()
yield self.update_accounts()
@defer.inlineCallbacks
def stop(self):
yield self.network.stop()
yield self.db.close()
yield self.headers.close()
@defer.inlineCallbacks
def update_headers(self, height=None, headers=None, count=1, subscription_update=False):
rewound = 0
while True:
height = len(self.headers) if height is None else height
if headers is None:
header_response = yield self.network.get_headers(height, 2001)
count = header_response['count']
headers = header_response['hex']
if count <= 0:
return
added = yield self.headers.connect(height, unhexlify(headers))
if added > 0:
self._on_header_controller.add(added)
if subscription_update and added == count:
# subscription updates are for latest header already
# so we don't need to check if there are newer / more
return
if added == 0:
# headers were invalid, start rewinding
height -= 1
rewound += 1
log.warning("Experiencing Blockchain Reorganization: Undoing header.")
else:
# added all headers, see if there are more
height += added
if height < 0:
raise IndexError(
"Blockchain reorganization rewound all the way back to genesis hash. "
"Something is very wrong. Maybe you are on the wrong blockchain?"
)
if rewound >= 50:
raise IndexError(
"Blockchain reorganization dropped {} headers. This is highly unusual. "
"Will not continue to attempt reorganizing."
.format(rewound)
)
headers = None
# if we made it this far and this was a subscription_update
# it means something was wrong and now we're doing a more
# robust sync, turn off subscription update shortcut
subscription_update = False
@defer.inlineCallbacks
def receive_header(self, response):
yield self._header_processing_lock.acquire()
try:
header = response[0]
yield self.update_headers(
height=header['height'], headers=header['hex'], subscription_update=True
)
finally:
self._header_processing_lock.release()
def update_accounts(self):
return defer.DeferredList([
self.update_account(a) for a in self.accounts
])
@defer.inlineCallbacks
def update_account(self, account): # type: (baseaccount.BaseAccount) -> defer.Defferred
# Before subscribing, download history for any addresses that don't have any,
# this avoids situation where we're getting status updates to addresses we know
# need to update anyways. Continue to get history and create more addresses until
# all missing addresses are created and history for them is fully restored.
yield account.ensure_address_gap()
addresses = yield account.get_addresses(max_used_times=0)
while addresses:
yield defer.DeferredList([
self.update_history(a) for a in addresses
])
addresses = yield account.ensure_address_gap()
# By this point all of the addresses should be restored and we
# can now subscribe all of them to receive updates.
all_addresses = yield account.get_addresses()
yield defer.DeferredList(
list(map(self.subscribe_history, all_addresses))
)
@defer.inlineCallbacks
def update_history(self, address):
remote_history = yield self.network.get_history(address)
local_history = yield self.get_local_history(address)
synced_history = []
for i, (hex_id, remote_height) in enumerate(map(itemgetter('tx_hash', 'height'), remote_history)):
synced_history.append((hex_id, remote_height))
if i < len(local_history) and local_history[i] == (hex_id, remote_height):
continue
lock = self._transaction_processing_locks.setdefault(hex_id, defer.DeferredLock())
yield lock.acquire()
try:
# see if we have a local copy of transaction, otherwise fetch it from server
raw, _, is_verified = yield self.db.get_transaction(hex_id)
save_tx = None
if raw is None:
_raw = yield self.network.get_transaction(hex_id)
tx = self.transaction_class(unhexlify(_raw))
save_tx = 'insert'
else:
tx = self.transaction_class(raw)
if remote_height > 0 and not is_verified:
is_verified = yield self.is_valid_transaction(tx, remote_height)
is_verified = 1 if is_verified else 0
if save_tx is None:
save_tx = 'update'
yield self.db.save_transaction_io(
save_tx, tx, remote_height, is_verified, address, self.address_to_hash160(address),
''.join('{}:{}:'.format(tx_id, tx_height) for tx_id, tx_height in synced_history)
)
log.debug(
"%s: sync'ed tx %s for address: %s, height: %s, verified: %s",
self.get_id(), hex_id, address, remote_height, is_verified
)
self._on_transaction_controller.add(TransactionEvent(address, tx, remote_height, is_verified))
except Exception:
log.exception('Failed to synchronize transaction:')
raise
finally:
lock.release()
if not lock.locked and hex_id in self._transaction_processing_locks:
del self._transaction_processing_locks[hex_id]
@defer.inlineCallbacks
def subscribe_history(self, address):
remote_status = yield self.network.subscribe_address(address)
local_status = yield self.get_local_status(address)
if local_status != remote_status:
yield self.update_history(address)
@defer.inlineCallbacks
def receive_status(self, response):
address, remote_status = response
local_status = yield self.get_local_status(address)
if local_status != remote_status:
yield self.update_history(address)
def broadcast(self, tx):
return self.network.broadcast(hexlify(tx.raw).decode())