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.blockchain = network.blockchain
36 self.transactions = {} # requested verifications (with height sent by the requestor)
37 self.verified_tx = storage.get('verified_tx3',{}) # height, timestamp of verified transactions
38 self.merkle_roots = storage.get('merkle_roots',{}) # hashed by me
39 self.lock = threading.Lock()
41 self.queue = Queue.Queue()
44 def get_confirmations(self, tx):
45 """ return the number of confirmations of a monitored transaction. """
47 if tx in self.verified_tx:
48 height, timestamp, pos = self.verified_tx[tx]
49 conf = (self.blockchain.local_height - height + 1)
50 if conf <= 0: timestamp = None
52 elif tx in self.transactions:
60 return conf, timestamp
63 def get_txpos(self, tx_hash):
64 "return position, even if the tx is unverified"
66 x = self.verified_tx.get(tx_hash)
67 y = self.transactions.get(tx_hash)
69 height, timestamp, pos = x
77 def get_height(self, tx_hash):
79 v = self.verified_tx.get(tx_hash)
80 height = v[0] if v else None
84 def add(self, tx_hash, tx_height):
85 """ add a transaction to the list of monitored transactions. """
88 if tx_hash not in self.transactions.keys():
89 self.transactions[tx_hash] = tx_height
92 with self.lock: self.running = False
95 with self.lock: return self.running
100 requested_merkle = []
102 while self.is_running():
104 for tx_hash, tx_height in self.transactions.items():
105 if tx_hash not in self.verified_tx:
106 if self.merkle_roots.get(tx_hash) is None and tx_hash not in requested_merkle:
107 if self.network.send([ ('blockchain.transaction.get_merkle',[tx_hash, tx_height]) ], lambda i,r: self.queue.put(r)):
108 print_error('requesting merkle', tx_hash)
109 requested_merkle.append(tx_hash)
112 r = self.queue.get(timeout=1)
119 print_error('Verifier received an error:', r)
127 if method == 'blockchain.transaction.get_merkle':
129 self.verify_merkle(tx_hash, result)
130 requested_merkle.remove(tx_hash)
133 def verify_merkle(self, tx_hash, result):
134 tx_height = result.get('block_height')
135 pos = result.get('pos')
136 self.merkle_roots[tx_hash] = self.hash_merkle_root(result['merkle'], tx_hash, pos)
137 header = self.blockchain.read_header(tx_height)
138 if not header: return
139 assert header.get('merkle_root') == self.merkle_roots[tx_hash]
140 # we passed all the tests
141 timestamp = header.get('timestamp')
143 self.verified_tx[tx_hash] = (tx_height, timestamp, pos)
144 print_error("verified %s"%tx_hash)
145 self.storage.put('verified_tx3', self.verified_tx, True)
146 self.network.trigger_callback('updated')
149 def hash_merkle_root(self, merkle_s, target_hash, pos):
150 h = hash_decode(target_hash)
151 for i in range(len(merkle_s)):
153 h = Hash( hash_decode(item) + h ) if ((pos >> i) & 1) else Hash( h + hash_decode(item) )
154 return hash_encode(h)
158 def undo_verifications(self, height):
160 items = self.verified_tx.items()[:]
161 for tx_hash, item in items:
162 tx_height, timestamp, pos = item
163 if tx_height >= height:
164 print_error("redoing", tx_hash)
166 self.verified_tx.pop(tx_hash)
167 if tx_hash in self.merkle_roots:
168 self.merkle_roots.pop(tx_hash)