3 # Electrum - lightweight Bitcoin client
4 # Copyright (C) 2012 thomasv@ecdsa.org
6 # This program is free software: you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation, either version 3 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program. If not, see <http://www.gnu.org/licenses/>.
20 import threading, time, Queue, os, sys, shutil
21 from util import user_dir, appdata_dir, print_error
27 class TxVerifier(threading.Thread):
28 """ Simple Payment Verification """
30 def __init__(self, network, storage):
31 threading.Thread.__init__(self)
33 self.storage = storage
34 self.network = network
35 self.transactions = {} # requested verifications (with height sent by the requestor)
36 self.verified_tx = storage.get('verified_tx3',{}) # height, timestamp of verified transactions
37 self.merkle_roots = storage.get('merkle_roots',{}) # hashed by me
38 self.lock = threading.Lock()
40 self.queue = Queue.Queue()
43 def get_confirmations(self, tx):
44 """ return the number of confirmations of a monitored transaction. """
46 if tx in self.verified_tx:
47 height, timestamp, pos = self.verified_tx[tx]
48 conf = (self.network.get_local_height() - height + 1)
49 if conf <= 0: timestamp = None
51 elif tx in self.transactions:
59 return conf, timestamp
62 def get_txpos(self, tx_hash):
63 "return position, even if the tx is unverified"
65 x = self.verified_tx.get(tx_hash)
66 y = self.transactions.get(tx_hash)
68 height, timestamp, pos = x
76 def get_height(self, tx_hash):
78 v = self.verified_tx.get(tx_hash)
79 height = v[0] if v else None
83 def add(self, tx_hash, tx_height):
84 """ add a transaction to the list of monitored transactions. """
87 if tx_hash not in self.transactions.keys():
88 self.transactions[tx_hash] = tx_height
91 with self.lock: self.running = False
94 with self.lock: return self.running
101 while self.is_running():
103 for tx_hash, tx_height in self.transactions.items():
104 if tx_hash not in self.verified_tx:
105 # do not request merkle branch before headers are available
106 if tx_height > self.network.blockchain.height():
108 if self.merkle_roots.get(tx_hash) is None and tx_hash not in requested_merkle:
109 if self.network.send([ ('blockchain.transaction.get_merkle',[tx_hash, tx_height]) ], lambda i,r: self.queue.put(r)):
110 print_error('requesting merkle', tx_hash)
111 requested_merkle.append(tx_hash)
114 r = self.queue.get(timeout=1)
121 print_error('Verifier received an error:', r)
129 if method == 'blockchain.transaction.get_merkle':
131 self.verify_merkle(tx_hash, result)
132 requested_merkle.remove(tx_hash)
135 def verify_merkle(self, tx_hash, result):
136 tx_height = result.get('block_height')
137 pos = result.get('pos')
138 self.merkle_roots[tx_hash] = self.hash_merkle_root(result['merkle'], tx_hash, pos)
139 header = self.network.get_header(tx_height)
140 if not header: return
141 assert header.get('merkle_root') == self.merkle_roots[tx_hash]
142 # we passed all the tests
143 timestamp = header.get('timestamp')
145 self.verified_tx[tx_hash] = (tx_height, timestamp, pos)
146 print_error("verified %s"%tx_hash)
147 self.storage.put('verified_tx3', self.verified_tx, True)
148 self.network.trigger_callback('updated')
151 def hash_merkle_root(self, merkle_s, target_hash, pos):
152 h = hash_decode(target_hash)
153 for i in range(len(merkle_s)):
155 h = Hash( hash_decode(item) + h ) if ((pos >> i) & 1) else Hash( h + hash_decode(item) )
156 return hash_encode(h)
160 def undo_verifications(self, height):
162 items = self.verified_tx.items()[:]
163 for tx_hash, item in items:
164 tx_height, timestamp, pos = item
165 if tx_height >= height:
166 print_error("redoing", tx_hash)
168 self.verified_tx.pop(tx_hash)
169 if tx_hash in self.merkle_roots:
170 self.merkle_roots.pop(tx_hash)