lbry-sdk/torba/client/baseledger.py
2018-12-11 15:59:15 -05:00

497 lines
19 KiB
Python

import os
import asyncio
import logging
from functools import partial
from binascii import hexlify, unhexlify
from io import StringIO
from typing import Dict, Type, Iterable, List, Optional
from operator import itemgetter
from collections import namedtuple
from torba.tasks import TaskGroup
from torba.client import baseaccount, basenetwork, basetransaction
from torba.client.basedatabase import BaseDatabase
from torba.client.baseheader import BaseHeaders
from torba.client.coinselection import CoinSelector
from torba.client.constants import COIN, NULL_HASH32
from torba.stream import StreamController
from torba.client.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'))):
pass
class AddressesGeneratedEvent(namedtuple('AddressesGeneratedEvent', ('address_manager', 'addresses'))):
pass
class BlockHeightEvent(namedtuple('BlockHeightEvent', ('height', 'change'))):
pass
class TransactionCacheItem:
__slots__ = '_tx', 'lock', 'has_tx'
def __init__(self,
tx: Optional[basetransaction.BaseTransaction] = None,
lock: Optional[asyncio.Lock] = None):
self.has_tx = asyncio.Event()
self.lock = lock or asyncio.Lock()
self._tx = self.tx = tx
@property
def tx(self) -> Optional[basetransaction.BaseTransaction]:
return self._tx
@tx.setter
def tx(self, tx: basetransaction.BaseTransaction):
self._tx = tx
if tx is not None:
self.has_tx.set()
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.db.ledger = self
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.process_status_update)
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.tx.height, e.tx.is_verified, e.tx.id
)
)
self._on_address_controller = StreamController()
self.on_address = self._on_address_controller.stream
self.on_address.listen(
lambda e: log.info('(%s) on_address: %s', self.get_id(), e.addresses)
)
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._tx_cache = {}
self._update_tasks = TaskGroup()
self._utxo_reservation_lock = asyncio.Lock()
self._header_processing_lock = asyncio.Lock()
self._address_update_locks: Dict[str, asyncio.Lock] = {}
@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())
def add_account(self, account: baseaccount.BaseAccount):
self.accounts.append(account)
async def get_private_key_for_address(self, address):
match = await self.db.get_address(address=address)
if match:
for account in self.accounts:
if match['account'] == account.public_key.address:
return account.get_private_key(match['chain'], match['position'])
async def get_effective_amount_estimators(self, funding_accounts: Iterable[baseaccount.BaseAccount]):
estimators = []
for account in funding_accounts:
utxos = await account.get_utxos()
for utxo in utxos:
estimators.append(utxo.get_estimator(self))
return estimators
async def get_spendable_utxos(self, amount: int, funding_accounts):
async with self._utxo_reservation_lock:
txos = await 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:
await self.reserve_outputs(s.txo for s in spendables)
return spendables
def reserve_outputs(self, txos):
return self.db.reserve_outputs(txos)
def release_outputs(self, txos):
return self.db.release_outputs(txos)
async def get_local_status_and_history(self, address):
address_details = await self.db.get_address(address=address)
history = address_details['history'] or ''
parts = history.split(':')[:-1]
return (
hexlify(sha256(history.encode())).decode() if history else None,
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])
async def start(self):
if not os.path.exists(self.path):
os.mkdir(self.path)
await asyncio.wait([
self.db.open(),
self.headers.open()
])
first_connection = self.network.on_connected.first
asyncio.ensure_future(self.network.start())
await first_connection
await self.join_network()
self.network.on_connected.listen(self.join_network)
async def join_network(self, *args):
log.info("Subscribing and updating accounts.")
await self.update_headers()
await self.network.subscribe_headers()
await self.subscribe_accounts()
await self._update_tasks.done.wait()
async def stop(self):
self._update_tasks.cancel()
await self._update_tasks.done.wait()
await self.network.stop()
await self.db.close()
await self.headers.close()
async def update_headers(self, height=None, headers=None, subscription_update=False):
rewound = 0
while True:
if height is None or height > len(self.headers):
# sometimes header subscription updates are for a header in the future
# which can't be connected, so we do a normal header sync instead
height = len(self.headers)
headers = None
subscription_update = False
if not headers:
header_response = await self.network.get_headers(height, 2001)
headers = header_response['hex']
if not headers:
# Nothing to do, network thinks we're already at the latest height.
return
added = await self.headers.connect(height, unhexlify(headers))
if added > 0:
height += added
self._on_header_controller.add(
BlockHeightEvent(self.headers.height, added))
if rewound > 0:
# we started rewinding blocks and apparently found
# a new chain
rewound = 0
await self.db.rewind_blockchain(height)
if subscription_update:
# subscription updates are for latest header already
# so we don't need to check if there are newer / more
# on another loop of update_headers(), just return instead
return
elif added == 0:
# we had headers to connect but none got connected, probably a reorganization
height -= 1
rewound += 1
log.warning(
"Blockchain Reorganization: attempting rewind to height %s from starting height %s",
height, height+rewound
)
else:
raise IndexError("headers.connect() returned negative number ({})".format(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 >= 100:
raise IndexError(
"Blockchain reorganization dropped {} headers. This is highly unusual. "
"Will not continue to attempt reorganizing. Please, delete the ledger "
"synchronization directory inside your wallet directory (folder: '{}') and "
"restart the program to synchronize from scratch."
.format(rewound, self.get_id())
)
headers = None # ready to download some more headers
# if we made it this far and this was a subscription_update
# it means something went wrong and now we're doing a more
# robust sync, turn off subscription update shortcut
subscription_update = False
async def receive_header(self, response):
async with self._header_processing_lock:
header = response[0]
await self.update_headers(
height=header['height'], headers=header['hex'], subscription_update=True
)
async def subscribe_accounts(self):
if self.network.is_connected and self.accounts:
await asyncio.wait([
self.subscribe_account(a) for a in self.accounts
])
async def subscribe_account(self, account: baseaccount.BaseAccount):
for address_manager in account.address_managers.values():
await self.subscribe_addresses(address_manager, await address_manager.get_addresses())
await account.ensure_address_gap()
async def announce_addresses(self, address_manager: baseaccount.AddressManager, addresses: List[str]):
await self.subscribe_addresses(address_manager, addresses)
await self._on_address_controller.add(
AddressesGeneratedEvent(address_manager, addresses)
)
async def subscribe_addresses(self, address_manager: baseaccount.AddressManager, addresses: List[str]):
if self.network.is_connected and addresses:
await asyncio.wait([
self.subscribe_address(address_manager, address) for address in addresses
])
async def subscribe_address(self, address_manager: baseaccount.AddressManager, address: str):
remote_status = await self.network.subscribe_address(address)
self._update_tasks.add(self.update_history(address, remote_status, address_manager))
def process_status_update(self, update):
address, remote_status = update
self._update_tasks.add(self.update_history(address, remote_status))
async def update_history(self, address, remote_status,
address_manager: baseaccount.AddressManager = None):
async with self._address_update_locks.setdefault(address, asyncio.Lock()):
local_status, local_history = await self.get_local_status_and_history(address)
if local_status == remote_status:
return
remote_history = await self.network.get_history(address)
cache_tasks = []
synced_history = StringIO()
for i, (txid, remote_height) in enumerate(map(itemgetter('tx_hash', 'height'), remote_history)):
if i < len(local_history) and local_history[i] == (txid, remote_height):
synced_history.write(f'{txid}:{remote_height}:')
else:
cache_tasks.append(asyncio.ensure_future(
self.cache_transaction(txid, remote_height)
))
for task in cache_tasks:
tx = await task
check_db_for_txos = []
for txi in tx.inputs:
if txi.txo_ref.txo is not None:
continue
cache_item = self._tx_cache.get(txi.txo_ref.tx_ref.id)
if cache_item is not None:
if cache_item.tx is None:
await cache_item.has_tx.wait()
assert cache_item.tx is not None
txi.txo_ref = cache_item.tx.outputs[txi.txo_ref.position].ref
else:
check_db_for_txos.append(txi.txo_ref.id)
referenced_txos = {
txo.id: txo for txo in await self.db.get_txos(txoid__in=check_db_for_txos)
}
for txi in tx.inputs:
if txi.txo_ref.txo is not None:
continue
referenced_txo = referenced_txos.get(txi.txo_ref.id)
if referenced_txo is not None:
txi.txo_ref = referenced_txo.ref
synced_history.write(f'{tx.id}:{tx.height}:')
await self.db.save_transaction_io(
tx, address, self.address_to_hash160(address), synced_history.getvalue()
)
await self._on_transaction_controller.add(TransactionEvent(address, tx))
if address_manager is None:
address_manager = await self.get_address_manager_for_address(address)
if address_manager is not None:
await address_manager.ensure_address_gap()
async def cache_transaction(self, txid, remote_height):
cache_item = self._tx_cache.get(txid)
if cache_item is None:
cache_item = self._tx_cache[txid] = TransactionCacheItem()
elif cache_item.tx is not None and \
cache_item.tx.height >= remote_height and \
(cache_item.tx.is_verified or remote_height < 1):
return cache_item.tx # cached tx is already up-to-date
async with cache_item.lock:
tx = cache_item.tx
if tx is None:
# check local db
tx = cache_item.tx = await self.db.get_transaction(txid=txid)
if tx is None:
# fetch from network
_raw = await self.network.get_transaction(txid)
if _raw:
tx = self.transaction_class(unhexlify(_raw))
await self.maybe_verify_transaction(tx, remote_height)
await self.db.insert_transaction(tx)
cache_item.tx = tx # make sure it's saved before caching it
return tx
if tx is None:
raise ValueError(f'Transaction {txid} was not in database and not on network.')
if remote_height > 0 and not tx.is_verified:
# tx from cache / db is not up-to-date
await self.maybe_verify_transaction(tx, remote_height)
await self.db.update_transaction(tx)
return tx
async def maybe_verify_transaction(self, tx, remote_height):
tx.height = remote_height
if 0 < remote_height <= len(self.headers):
merkle = await self.network.get_merkle(tx.id, remote_height)
merkle_root = self.get_root_of_merkle_tree(merkle['merkle'], merkle['pos'], tx.hash)
header = self.headers[remote_height]
tx.position = merkle['pos']
tx.is_verified = merkle_root == header['merkle_root']
async def get_address_manager_for_address(self, address) -> Optional[baseaccount.AddressManager]:
details = await self.db.get_address(address=address)
for account in self.accounts:
if account.id == details['account']:
return account.address_managers[details['chain']]
return None
def broadcast(self, tx):
return self.network.broadcast(hexlify(tx.raw).decode())
async def wait(self, tx: basetransaction.BaseTransaction, height=-1):
addresses = set()
for txi in tx.inputs:
if txi.txo_ref.txo is not None:
addresses.add(
self.hash160_to_address(txi.txo_ref.txo.script.values['pubkey_hash'])
)
for txo in tx.outputs:
addresses.add(
self.hash160_to_address(txo.script.values['pubkey_hash'])
)
records = await self.db.get_addresses(cols=('address',), address__in=addresses)
await asyncio.wait([
self.on_transaction.where(partial(
lambda a, e: a == e.address and e.tx.height >= height and e.tx.id == tx.id,
address_record['address']
)) for address_record in records
])