#!/usr/bin/env python # # Electrum - lightweight Bitcoin client # Copyright (C) 2014 Thomas Voegtlin # # Permission is hereby granted, free of charge, to any person # obtaining a copy of this software and associated documentation files # (the "Software"), to deal in the Software without restriction, # including without limitation the rights to use, copy, modify, merge, # publish, distribute, sublicense, and/or sell copies of the Software, # and to permit persons to whom the Software is furnished to do so, # subject to the following conditions: # # The above copyright notice and this permission notice shall be # included in all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE # SOFTWARE. from threading import Lock import hashlib # from .bitcoin import Hash, hash_encode from .transaction import Transaction from .util import ThreadJob, bh2u class Synchronizer(ThreadJob): '''The synchronizer keeps the wallet up-to-date with its set of addresses and their transactions. It subscribes over the network to wallet addresses, gets the wallet to generate new addresses when necessary, requests the transaction history of any addresses we don't have the full history of, and requests binary transaction data of any transactions the wallet doesn't have. External interface: __init__() and add() member functions. ''' def __init__(self, wallet, network): self.wallet = wallet self.network = network self.new_addresses = set() # Entries are (tx_hash, tx_height) tuples self.requested_tx = {} self.requested_histories = {} self.requested_addrs = set() self.lock = Lock() self.initialized = False self.initialize() def parse_response(self, response): if response.get('error'): self.print_error("response error:", response) return None, None return response['params'], response['result'] def is_up_to_date(self): return (not self.requested_tx and not self.requested_histories and not self.requested_addrs) def release(self): self.network.unsubscribe(self.on_address_status) def add(self, address): '''This can be called from the proxy or GUI threads.''' with self.lock: self.new_addresses.add(address) def subscribe_to_addresses(self, addresses): if addresses: self.requested_addrs |= addresses self.network.subscribe_to_addresses(addresses, self.on_address_status) def get_status(self, h): if not h: return None status = '' for tx_hash, height in h: status += tx_hash + ':%d:' % height return bh2u(hashlib.sha256(status.encode('ascii')).digest()) def on_address_status(self, response): if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: return addr = params[0] history = self.wallet.history.get(addr, []) if self.get_status(history) != result: # note that at this point 'result' can be None; # if we had a history for addr but now the server is telling us # there is no history if addr not in self.requested_histories: self.requested_histories[addr] = result self.network.request_address_history(addr, self.on_address_history) # remove addr from list only after it is added to requested_histories if addr in self.requested_addrs: # Notifications won't be in self.requested_addrs.remove(addr) def on_address_history(self, response): if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: return addr = params[0] try: server_status = self.requested_histories[addr] except KeyError: # note: server_status can be None even if we asked for the history, # so it is not sufficient to test that self.print_error("receiving history (unsolicited)", addr, len(result)) return self.print_error("receiving history", addr, len(result)) hashes = set(map(lambda item: item['tx_hash'], result)) hist = list(map(lambda item: (item['tx_hash'], item['height']), result)) # tx_fees tx_fees = [(item['tx_hash'], item.get('fee')) for item in result] tx_fees = dict(filter(lambda x:x[1] is not None, tx_fees)) # Note if the server hasn't been patched to sort the items properly if hist != sorted(hist, key=lambda x:x[1]): interface = self.network.interface # note: we don't actually know which interface was used if it was *just* changed if interface: interface.print_error("serving improperly sorted address histories") # Check that txids are unique if len(hashes) != len(result): self.print_error("error: server history has non-unique txids: %s"% addr) # Check that the status corresponds to what was announced elif self.get_status(hist) != server_status: self.print_error("error: status mismatch: %s" % addr) else: # Store received history self.wallet.receive_history_callback(addr, hist, tx_fees) # Request transactions we don't have self.request_missing_txs(hist) # Remove request; this allows up_to_date to be True self.requested_histories.pop(addr) def on_tx_response(self, response): if self.wallet.synchronizer is None and self.initialized: return # we have been killed, this was just an orphan callback params, result = self.parse_response(response) if not params: return tx_hash = params[0] #assert tx_hash == hash_encode(Hash(bytes.fromhex(result))) tx = Transaction(result) try: tx.deserialize() except Exception: self.print_msg("cannot deserialize transaction, skipping", tx_hash) return tx_height = self.requested_tx.pop(tx_hash) self.wallet.receive_tx_callback(tx_hash, tx, tx_height) self.print_error("received tx %s height: %d bytes: %d" % (tx_hash, tx_height, len(tx.raw))) # callbacks self.network.trigger_callback('new_transaction', tx) if not self.requested_tx: self.network.trigger_callback('updated') def request_missing_txs(self, hist): # "hist" is a list of [tx_hash, tx_height] lists transaction_hashes = [] for tx_hash, tx_height in hist: if tx_hash in self.requested_tx: continue if tx_hash in self.wallet.transactions: continue transaction_hashes.append(tx_hash) self.requested_tx[tx_hash] = tx_height self.network.get_transactions(transaction_hashes, self.on_tx_response) def initialize(self): '''Check the initial state of the wallet. Subscribe to all its addresses, and request any transactions in its address history we don't have. ''' for history in self.wallet.history.values(): # Old electrum servers returned ['*'] when all history for # the address was pruned. This no longer happens but may # remain in old wallets. if history == ['*']: continue self.request_missing_txs(history) if self.requested_tx: self.print_error("missing tx", self.requested_tx) self.subscribe_to_addresses(set(self.wallet.get_addresses())) self.initialized = True def run(self): '''Called from the network proxy thread main loop.''' # 1. Create new addresses self.wallet.synchronize() # 2. Subscribe to new addresses with self.lock: addresses = self.new_addresses self.new_addresses = set() self.subscribe_to_addresses(addresses) # 3. Detect if situation has changed up_to_date = self.is_up_to_date() if up_to_date != self.wallet.is_up_to_date(): self.wallet.set_up_to_date(up_to_date) self.network.trigger_callback('updated')