backends/bitcoind/blockchain_processor.py

   1 import ast
   2 import hashlib
   3 from json import dumps, loads
   4 import leveldb
   5 import os
   6 from Queue import Queue
   7 import random
   8 import sys
   9 import time
  10 import threading
  11 import traceback
  12 import urllib
  13
  14 from backends.bitcoind import deserialize
  15 from processor import Processor, print_log
  16 from utils import *
  17
  18
  19 class BlockchainProcessor(Processor):
  20
  21     def __init__(self, config, shared):
  22         Processor.__init__(self)
  23
  24         self.shared = shared
  25         self.config = config
  26         self.up_to_date = False
  27         self.watched_addresses = []
  28         self.history_cache = {}
  29         self.chunk_cache = {}
  30         self.cache_lock = threading.Lock()
  31         self.headers_data = ''
  32
  33         self.mempool_addresses = {}
  34         self.mempool_hist = {}
  35         self.mempool_hashes = []
  36         self.mempool_lock = threading.Lock()
  37
  38         self.address_queue = Queue()
  39         self.dbpath = config.get('leveldb', 'path')
  40         self.pruning_limit = config.getint('leveldb', 'pruning_limit')
  41         self.db_version = 1 # increase this when database needs to be updated
  42
  43         self.dblock = threading.Lock()
  44         try:
  45             self.db = leveldb.LevelDB(self.dbpath)
  46         except:
  47             traceback.print_exc(file=sys.stdout)
  48             self.shared.stop()
  49
  50         self.bitcoind_url = 'http://%s:%s@%s:%s/' % (
  51             config.get('bitcoind', 'user'),
  52             config.get('bitcoind', 'password'),
  53             config.get('bitcoind', 'host'),
  54             config.get('bitcoind', 'port'))
  55
  56         self.height = 0
  57         self.is_test = False
  58         self.sent_height = 0
  59         self.sent_header = None
  60
  61         try:
  62             hist = self.deserialize(self.db.Get('height'))
  63             self.last_hash, self.height, db_version = hist[0]
  64             print_log("Database version", self.db_version)
  65             print_log("Blockchain height", self.height)
  66         except:
  67             traceback.print_exc(file=sys.stdout)
  68             print_log('initializing database')
  69             self.height = 0
  70             self.last_hash = '000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
  71
  72         # check version
  73         if self.db_version != db_version:
  74             print_log("Your database '%s' is deprecated. Please create a new database"%self.dbpath)
  75             self.shared.stop()
  76             return
  77
  78         # catch_up headers
  79         self.init_headers(self.height)
  80
  81         threading.Timer(0, lambda: self.catch_up(sync=False)).start()
  82         while not shared.stopped() and not self.up_to_date:
  83             try:
  84                 time.sleep(1)
  85             except:
  86                 print "keyboard interrupt: stopping threads"
  87                 shared.stop()
  88                 sys.exit(0)
  89
  90         print_log("blockchain is up to date.")
  91
  92         threading.Timer(10, self.main_iteration).start()
  93
  94     def bitcoind(self, method, params=[]):
  95         postdata = dumps({"method": method, 'params': params, 'id': 'jsonrpc'})
  96         try:
  97             respdata = urllib.urlopen(self.bitcoind_url, postdata).read()
  98         except:
  99             traceback.print_exc(file=sys.stdout)
 100             self.shared.stop()
 101
 102         r = loads(respdata)
 103         if r['error'] is not None:
 104             raise BaseException(r['error'])
 105         return r.get('result')
 106
 107     def serialize(self, h):
 108         s = ''
 109         for txid, txpos, height in h:
 110             s += self.serialize_item(txid, txpos, height)
 111         return s
 112
 113     def serialize_item(self, txid, txpos, height, spent=chr(0)):
 114         s = (txid + int_to_hex(txpos, 4) + int_to_hex(height, 3)).decode('hex') + spent
 115         return s
 116
 117     def deserialize_item(self,s):
 118         txid = s[0:32].encode('hex')
 119         txpos = int(rev_hex(s[32:36].encode('hex')), 16)
 120         height = int(rev_hex(s[36:39].encode('hex')), 16)
 121         spent = s[39:40]
 122         return (txid, txpos, height, spent)
 123
 124     def deserialize(self, s):
 125         h = []
 126         while s:
 127             txid, txpos, height, spent = self.deserialize_item(s[0:40])
 128             h.append((txid, txpos, height))
 129             if spent == chr(1):
 130                 txid, txpos, height, spent = self.deserialize_item(s[40:80])
 131                 h.append((txid, txpos, height))
 132             s = s[80:]
 133         return h
 134
 135     def block2header(self, b):
 136         return {
 137             "block_height": b.get('height'),
 138             "version": b.get('version'),
 139             "prev_block_hash": b.get('previousblockhash'),
 140             "merkle_root": b.get('merkleroot'),
 141             "timestamp": b.get('time'),
 142             "bits": int(b.get('bits'), 16),
 143             "nonce": b.get('nonce'),
 144         }
 145
 146     def get_header(self, height):
 147         block_hash = self.bitcoind('getblockhash', [height])
 148         b = self.bitcoind('getblock', [block_hash])
 149         return self.block2header(b)
 150
 151     def init_headers(self, db_height):
 152         self.chunk_cache = {}
 153         self.headers_filename = os.path.join(self.dbpath, 'blockchain_headers')
 154
 155         if os.path.exists(self.headers_filename):
 156             height = os.path.getsize(self.headers_filename)/80 - 1   # the current height
 157             if height > 0:
 158                 prev_hash = self.hash_header(self.read_header(height))
 159             else:
 160                 prev_hash = None
 161         else:
 162             open(self.headers_filename, 'wb').close()
 163             prev_hash = None
 164             height = -1
 165
 166         if height < db_height:
 167             print_log("catching up missing headers:", height, db_height)
 168
 169         try:
 170             while height < db_height:
 171                 height = height + 1
 172                 header = self.get_header(height)
 173                 if height > 1:
 174                     assert prev_hash == header.get('prev_block_hash')
 175                 self.write_header(header, sync=False)
 176                 prev_hash = self.hash_header(header)
 177                 if (height % 1000) == 0:
 178                     print_log("headers file:", height)
 179         except KeyboardInterrupt:
 180             self.flush_headers()
 181             sys.exit()
 182
 183         self.flush_headers()
 184
 185     def hash_header(self, header):
 186         return rev_hex(Hash(header_to_string(header).decode('hex')).encode('hex'))
 187
 188     def read_header(self, block_height):
 189         if os.path.exists(self.headers_filename):
 190             with open(self.headers_filename, 'rb') as f:
 191                 f.seek(block_height * 80)
 192                 h = f.read(80)
 193             if len(h) == 80:
 194                 h = header_from_string(h)
 195                 return h
 196
 197     def read_chunk(self, index):
 198         with open(self.headers_filename, 'rb') as f:
 199             f.seek(index*2016*80)
 200             chunk = f.read(2016*80)
 201         return chunk.encode('hex')
 202
 203     def write_header(self, header, sync=True):
 204         if not self.headers_data:
 205             self.headers_offset = header.get('block_height')
 206
 207         self.headers_data += header_to_string(header).decode('hex')
 208         if sync or len(self.headers_data) > 40*100:
 209             self.flush_headers()
 210
 211         with self.cache_lock:
 212             chunk_index = header.get('block_height')/2016
 213             if self.chunk_cache.get(chunk_index):
 214                 self.chunk_cache.pop(chunk_index)
 215
 216     def pop_header(self):
 217         # we need to do this only if we have not flushed
 218         if self.headers_data:
 219             self.headers_data = self.headers_data[:-40]
 220
 221     def flush_headers(self):
 222         if not self.headers_data:
 223             return
 224         with open(self.headers_filename, 'rb+') as f:
 225             f.seek(self.headers_offset*80)
 226             f.write(self.headers_data)
 227         self.headers_data = ''
 228
 229     def get_chunk(self, i):
 230         # store them on disk; store the current chunk in memory
 231         with self.cache_lock:
 232             chunk = self.chunk_cache.get(i)
 233             if not chunk:
 234                 chunk = self.read_chunk(i)
 235                 self.chunk_cache[i] = chunk
 236
 237         return chunk
 238
 239     def get_mempool_transaction(self, txid):
 240         try:
 241             raw_tx = self.bitcoind('getrawtransaction', [txid, 0, -1])
 242         except:
 243             return None
 244
 245         vds = deserialize.BCDataStream()
 246         vds.write(raw_tx.decode('hex'))
 247
 248         return deserialize.parse_Transaction(vds, is_coinbase=False)
 249
 250     def get_history(self, addr, cache_only=False):
 251         with self.cache_lock:
 252             hist = self.history_cache.get(addr)
 253         if hist is not None:
 254             return hist
 255         if cache_only:
 256             return -1
 257
 258         with self.dblock:
 259             try:
 260                 hist = self.deserialize(self.db.Get(addr))
 261                 is_known = True
 262             except:
 263                 hist = []
 264                 is_known = False
 265
 266         # sort history, because redeeming transactions are next to the corresponding txout
 267         hist.sort(key=lambda tup: tup[2])
 268
 269         # uniqueness
 270         hist = set(map(lambda x: (x[0], x[2]), hist))
 271
 272         # add memory pool
 273         with self.mempool_lock:
 274             for txid in self.mempool_hist.get(addr, []):
 275                 hist.append((txid, 0, 0))
 276
 277         # convert to dict
 278         hist = map(lambda x: {'tx_hash': x[0], 'height': x[1]}, hist)
 279
 280         # add something to distinguish between unused and empty addresses
 281         if hist == [] and is_known:
 282             hist = ['*']
 283
 284         with self.cache_lock:
 285             self.history_cache[addr] = hist
 286         return hist
 287
 288     def get_status(self, addr, cache_only=False):
 289         tx_points = self.get_history(addr, cache_only)
 290         if cache_only and tx_points == -1:
 291             return -1
 292
 293         if not tx_points:
 294             return None
 295         if tx_points == ['*']:
 296             return '*'
 297         status = ''
 298         for tx in tx_points:
 299             status += tx.get('tx_hash') + ':%d:' % tx.get('height')
 300         return hashlib.sha256(status).digest().encode('hex')
 301
 302     def get_merkle(self, tx_hash, height):
 303
 304         block_hash = self.bitcoind('getblockhash', [height])
 305         b = self.bitcoind('getblock', [block_hash])
 306         tx_list = b.get('tx')
 307         tx_pos = tx_list.index(tx_hash)
 308
 309         merkle = map(hash_decode, tx_list)
 310         target_hash = hash_decode(tx_hash)
 311         s = []
 312         while len(merkle) != 1:
 313             if len(merkle) % 2:
 314                 merkle.append(merkle[-1])
 315             n = []
 316             while merkle:
 317                 new_hash = Hash(merkle[0] + merkle[1])
 318                 if merkle[0] == target_hash:
 319                     s.append(hash_encode(merkle[1]))
 320                     target_hash = new_hash
 321                 elif merkle[1] == target_hash:
 322                     s.append(hash_encode(merkle[0]))
 323                     target_hash = new_hash
 324                 n.append(new_hash)
 325                 merkle = merkle[2:]
 326             merkle = n
 327
 328         return {"block_height": height, "merkle": s, "pos": tx_pos}
 329
 330
 331     def add_to_history(self, addr, tx_hash, tx_pos, tx_height):
 332         # keep it sorted
 333         s = self.serialize_item(tx_hash, tx_pos, tx_height) + 40*chr(0)
 334         assert len(s) == 80
 335
 336         serialized_hist = self.batch_list[addr]
 337
 338         l = len(serialized_hist)/80
 339         for i in range(l-1, -1, -1):
 340             item = serialized_hist[80*i:80*(i+1)]
 341             item_height = int(rev_hex(item[36:39].encode('hex')), 16)
 342             if item_height < tx_height:
 343                 serialized_hist = serialized_hist[0:80*(i+1)] + s + serialized_hist[80*(i+1):]
 344                 break
 345         else:
 346             serialized_hist = s + serialized_hist
 347
 348         self.batch_list[addr] = serialized_hist
 349
 350         # backlink
 351         txo = (tx_hash + int_to_hex(tx_pos, 4)).decode('hex')
 352         self.batch_txio[txo] = addr
 353
 354
 355
 356     def revert_add_to_history(self, addr, tx_hash, tx_pos, tx_height):
 357
 358         serialized_hist = self.batch_list[addr]
 359         s = self.serialize_item(tx_hash, tx_pos, tx_height) + 40*chr(0)
 360         if serialized_hist.find(s) == -1: raise
 361         serialized_hist = serialized_hist.replace(s, '')
 362         self.batch_list[addr] = serialized_hist
 363
 364
 365
 366     def prune_history(self, addr, undo):
 367         # remove items that have bit set to one
 368         if undo.get(addr) is None: undo[addr] = []
 369
 370         serialized_hist = self.batch_list[addr]
 371         l = len(serialized_hist)/80
 372         for i in range(l):
 373             if len(serialized_hist)/80 < self.pruning_limit: break
 374             item = serialized_hist[80*i:80*(i+1)]
 375             if item[39:40] == chr(1):
 376                 assert item[79:80] == chr(2)
 377                 serialized_hist = serialized_hist[0:80*i] + serialized_hist[80*(i+1):]
 378                 undo[addr].append(item)  # items are ordered
 379         self.batch_list[addr] = serialized_hist
 380
 381
 382     def revert_prune_history(self, addr, undo):
 383         # restore removed items
 384         serialized_hist = self.batch_list[addr]
 385
 386         if undo.get(addr) is not None:
 387             itemlist = undo.pop(addr)
 388         else:
 389             return
 390
 391         if not itemlist: return
 392
 393         l = len(serialized_hist)/80
 394         tx_item = ''
 395         for i in range(l-1, -1, -1):
 396             if tx_item == '':
 397                 if not itemlist:
 398                     break
 399                 else:
 400                     tx_item = itemlist.pop(-1) # get the last element
 401                     tx_height = int(rev_hex(tx_item[36:39].encode('hex')), 16)
 402
 403             item = serialized_hist[80*i:80*(i+1)]
 404             item_height = int(rev_hex(item[36:39].encode('hex')), 16)
 405
 406             if item_height < tx_height:
 407                 serialized_hist = serialized_hist[0:80*(i+1)] + tx_item + serialized_hist[80*(i+1):]
 408                 tx_item = ''
 409
 410         else:
 411             serialized_hist = ''.join(itemlist) + tx_item + serialized_hist
 412
 413         self.batch_list[addr] = serialized_hist
 414
 415
 416     def set_spent_bit(self, addr, txi, is_spent, txid=None, index=None, height=None):
 417         serialized_hist = self.batch_list[addr]
 418         l = len(serialized_hist)/80
 419         for i in range(l):
 420             item = serialized_hist[80*i:80*(i+1)]
 421             if item[0:36] == txi:
 422                 if is_spent:
 423                     new_item = item[0:39] + chr(1) + self.serialize_item(txid, index, height, chr(2))
 424                 else:
 425                     new_item = item[0:39] + chr(0) + chr(0)*40
 426                 serialized_hist = serialized_hist[0:80*i] + new_item + serialized_hist[80*(i+1):]
 427                 break
 428         else:
 429             hist = self.deserialize(serialized_hist)
 430             raise BaseException("prevout not found", addr, hist, txi.encode('hex'))
 431
 432         self.batch_list[addr] = serialized_hist
 433
 434
 435     def unset_spent_bit(self, addr, txi):
 436         self.set_spent_bit(addr, txi, False)
 437         self.batch_txio[txi] = addr
 438
 439
 440     def deserialize_block(self, block):
 441         txlist = block.get('tx')
 442         tx_hashes = []  # ordered txids
 443         txdict = {}     # deserialized tx
 444         is_coinbase = True
 445         for raw_tx in txlist:
 446             tx_hash = hash_encode(Hash(raw_tx.decode('hex')))
 447             tx_hashes.append(tx_hash)
 448             vds = deserialize.BCDataStream()
 449             vds.write(raw_tx.decode('hex'))
 450             tx = deserialize.parse_Transaction(vds, is_coinbase)
 451             txdict[tx_hash] = tx
 452             is_coinbase = False
 453         return tx_hashes, txdict
 454
 455     def get_undo_info(self, height):
 456         s = self.db.Get("undo%d" % (height % 100))
 457         return eval(s)
 458
 459     def write_undo_info(self, batch, height, undo_info):
 460         if self.is_test or height > self.bitcoind_height - 100:
 461             batch.Put("undo%d" % (height % 100), repr(undo_info))
 462
 463     def import_block(self, block, block_hash, block_height, sync, revert=False):
 464
 465         self.batch_list = {}  # address -> history
 466         self.batch_txio = {}  # transaction i/o -> address
 467
 468         block_inputs = []
 469         block_outputs = []
 470         addr_to_read = []
 471
 472         # deserialize transactions
 473         t0 = time.time()
 474         tx_hashes, txdict = self.deserialize_block(block)
 475
 476         t00 = time.time()
 477
 478         # undo info
 479         if revert:
 480             undo_info = self.get_undo_info(block_height)
 481         else:
 482             undo_info = {}
 483
 484
 485         if not revert:
 486             # read addresses of tx inputs
 487             for tx in txdict.values():
 488                 for x in tx.get('inputs'):
 489                     txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 490                     block_inputs.append(txi)
 491
 492             block_inputs.sort()
 493             for txi in block_inputs:
 494                 try:
 495                     addr = self.db.Get(txi)
 496                 except:
 497                     # print "addr not in db", txi.encode('hex')
 498                     # the input could come from the same block
 499                     continue
 500                 self.batch_txio[txi] = addr
 501                 addr_to_read.append(addr)
 502
 503         else:
 504             for txid, tx in txdict.items():
 505                 for x in tx.get('outputs'):
 506                     txo = (txid + int_to_hex(x.get('index'), 4)).decode('hex')
 507                     block_outputs.append(txo)
 508                     addr_to_read.append( x.get('address') )
 509
 510                 undo = undo_info.get(txid)
 511                 for i, x in enumerate(tx.get('inputs')):
 512                     addr = undo['prev_addr'][i]
 513                     addr_to_read.append(addr)
 514
 515
 516
 517
 518
 519         # read histories of addresses
 520         for txid, tx in txdict.items():
 521             for x in tx.get('outputs'):
 522                 addr_to_read.append(x.get('address'))
 523
 524         addr_to_read.sort()
 525         for addr in addr_to_read:
 526             try:
 527                 self.batch_list[addr] = self.db.Get(addr)
 528             except:
 529                 self.batch_list[addr] = ''
 530
 531
 532         # process
 533         t1 = time.time()
 534
 535         if revert:
 536             tx_hashes = tx_hashes[::-1]
 537
 538
 539         for txid in tx_hashes:  # must be ordered
 540             tx = txdict[txid]
 541             if not revert:
 542
 543                 undo = { 'prev_addr':[] } # contains the list of pruned items for each address in the tx; also, 'prev_addr' is a list of prev addresses
 544
 545                 prev_addr = []
 546                 for i, x in enumerate(tx.get('inputs')):
 547                     txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 548                     addr = self.batch_txio[txi]
 549
 550                     # add redeem item to the history.
 551                     # add it right next to the input txi? this will break history sorting, but it's ok if I neglect tx inputs during search
 552                     self.set_spent_bit(addr, txi, True, txid, i, block_height)
 553
 554                     # when I prune, prune a pair
 555                     self.prune_history(addr, undo)
 556                     prev_addr.append(addr)
 557
 558                 undo['prev_addr'] = prev_addr
 559
 560                 # here I add only the outputs to history; maybe I want to add inputs too (that's in the other loop)
 561                 for x in tx.get('outputs'):
 562                     addr = x.get('address')
 563                     self.add_to_history(addr, txid, x.get('index'), block_height)
 564                     self.prune_history(addr, undo)  # prune here because we increased the length of the history
 565
 566                 undo_info[txid] = undo
 567
 568             else:
 569
 570                 undo = undo_info.pop(txid)
 571
 572                 for x in tx.get('outputs'):
 573                     addr = x.get('address')
 574                     self.revert_prune_history(addr, undo)
 575                     self.revert_add_to_history(addr, txid, x.get('index'), block_height)
 576
 577                 prev_addr = undo.pop('prev_addr')
 578                 for i, x in enumerate(tx.get('inputs')):
 579                     addr = prev_addr[i]
 580                     self.revert_prune_history(addr, undo)
 581                     txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 582                     self.unset_spent_bit(addr, txi)
 583
 584                 assert undo == {}
 585
 586         if revert:
 587             assert undo_info == {}
 588
 589
 590         # write
 591         max_len = 0
 592         max_addr = ''
 593         t2 = time.time()
 594
 595         batch = leveldb.WriteBatch()
 596         for addr, serialized_hist in self.batch_list.items():
 597             batch.Put(addr, serialized_hist)
 598             l = len(serialized_hist)/80
 599             if l > max_len:
 600                 max_len = l
 601                 max_addr = addr
 602
 603         if not revert:
 604             # add new created outputs
 605             for txio, addr in self.batch_txio.items():
 606                 batch.Put(txio, addr)
 607             # delete spent inputs
 608             for txi in block_inputs:
 609                 batch.Delete(txi)
 610             # add undo info
 611             self.write_undo_info(batch, block_height, undo_info)
 612         else:
 613             # restore spent inputs
 614             for txio, addr in self.batch_txio.items():
 615                 # print "restoring spent input", repr(txio)
 616                 batch.Put(txio, addr)
 617             # delete spent outputs
 618             for txo in block_outputs:
 619                 batch.Delete(txo)
 620
 621         # add the max
 622         batch.Put('height', self.serialize([(block_hash, block_height, self.db_version)]))
 623
 624         # actual write
 625         self.db.Write(batch, sync=sync)
 626
 627         t3 = time.time()
 628         if t3 - t0 > 10 and not sync:
 629             print_log("block", block_height,
 630                       "parse:%0.2f " % (t00 - t0),
 631                       "read:%0.2f " % (t1 - t00),
 632                       "proc:%.2f " % (t2-t1),
 633                       "write:%.2f " % (t3-t2),
 634                       "max:", max_len, max_addr)
 635
 636         for addr in self.batch_list.keys():
 637             self.invalidate_cache(addr)
 638
 639     def add_request(self, request):
 640         # see if we can get if from cache. if not, add to queue
 641         if self.process(request, cache_only=True) == -1:
 642             self.queue.put(request)
 643
 644     def process(self, request, cache_only=False):
 645         #print "abe process", request
 646
 647         message_id = request['id']
 648         method = request['method']
 649         params = request.get('params', [])
 650         result = None
 651         error = None
 652
 653         if method == 'blockchain.numblocks.subscribe':
 654             result = self.height
 655
 656         elif method == 'blockchain.headers.subscribe':
 657             result = self.header
 658
 659         elif method == 'blockchain.address.subscribe':
 660             try:
 661                 address = params[0]
 662                 result = self.get_status(address, cache_only)
 663                 self.watch_address(address)
 664             except BaseException, e:
 665                 error = str(e) + ': ' + address
 666                 print_log("error:", error)
 667
 668         elif method == 'blockchain.address.unsubscribe':
 669             try:
 670                 password = params[0]
 671                 address = params[1]
 672                 if password == self.config.get('server', 'password'):
 673                     self.watched_addresses.remove(address)
 674                     # print_log('unsubscribed', address)
 675                     result = "ok"
 676                 else:
 677                     print_log('incorrect password')
 678                     result = "authentication error"
 679             except BaseException, e:
 680                 error = str(e) + ': ' + address
 681                 print_log("error:", error)
 682
 683         elif method == 'blockchain.address.get_history':
 684             try:
 685                 address = params[0]
 686                 result = self.get_history(address, cache_only)
 687             except BaseException, e:
 688                 error = str(e) + ': ' + address
 689                 print_log("error:", error)
 690
 691         elif method == 'blockchain.block.get_header':
 692             if cache_only:
 693                 result = -1
 694             else:
 695                 try:
 696                     height = params[0]
 697                     result = self.get_header(height)
 698                 except BaseException, e:
 699                     error = str(e) + ': %d' % height
 700                     print_log("error:", error)
 701
 702         elif method == 'blockchain.block.get_chunk':
 703             if cache_only:
 704                 result = -1
 705             else:
 706                 try:
 707                     index = params[0]
 708                     result = self.get_chunk(index)
 709                 except BaseException, e:
 710                     error = str(e) + ': %d' % index
 711                     print_log("error:", error)
 712
 713         elif method == 'blockchain.transaction.broadcast':
 714             try:
 715                 txo = self.bitcoind('sendrawtransaction', params)
 716                 print_log("sent tx:", txo)
 717                 result = txo
 718             except BaseException, e:
 719                 result = str(e)  # do not send an error
 720                 print_log("error:", result, params)
 721
 722         elif method == 'blockchain.transaction.get_merkle':
 723             if cache_only:
 724                 result = -1
 725             else:
 726                 try:
 727                     tx_hash = params[0]
 728                     tx_height = params[1]
 729                     result = self.get_merkle(tx_hash, tx_height)
 730                 except BaseException, e:
 731                     error = str(e) + ': ' + repr(params)
 732                     print_log("get_merkle error:", error)
 733
 734         elif method == 'blockchain.transaction.get':
 735             try:
 736                 tx_hash = params[0]
 737                 height = params[1]
 738                 result = self.bitcoind('getrawtransaction', [tx_hash, 0, height])
 739             except BaseException, e:
 740                 error = str(e) + ': ' + repr(params)
 741                 print_log("tx get error:", error)
 742
 743         else:
 744             error = "unknown method:%s" % method
 745
 746         if cache_only and result == -1:
 747             return -1
 748
 749         if error:
 750             self.push_response({'id': message_id, 'error': error})
 751         elif result != '':
 752             self.push_response({'id': message_id, 'result': result})
 753
 754     def watch_address(self, addr):
 755         if addr not in self.watched_addresses:
 756             self.watched_addresses.append(addr)
 757
 758     def catch_up(self, sync=True):
 759         t1 = time.time()
 760
 761         while not self.shared.stopped():
 762             # are we done yet?
 763             info = self.bitcoind('getinfo')
 764             self.bitcoind_height = info.get('blocks')
 765             bitcoind_block_hash = self.bitcoind('getblockhash', [self.bitcoind_height])
 766             if self.last_hash == bitcoind_block_hash:
 767                 self.up_to_date = True
 768                 break
 769
 770             # not done..
 771             self.up_to_date = False
 772             next_block_hash = self.bitcoind('getblockhash', [self.height + 1])
 773             next_block = self.bitcoind('getblock', [next_block_hash, 1])
 774
 775             # fixme: this is unsafe, if we revert when the undo info is not yet written
 776             revert = (random.randint(1, 100) == 1) if self.is_test else False
 777
 778             if (next_block.get('previousblockhash') == self.last_hash) and not revert:
 779
 780                 self.import_block(next_block, next_block_hash, self.height+1, sync)
 781                 self.height = self.height + 1
 782                 self.write_header(self.block2header(next_block), sync)
 783                 self.last_hash = next_block_hash
 784
 785                 if self.height % 100 == 0 and not sync:
 786                     t2 = time.time()
 787                     print_log("catch_up: block %d (%.3fs)" % (self.height, t2 - t1))
 788                     t1 = t2
 789
 790             else:
 791                 # revert current block
 792                 block = self.bitcoind('getblock', [self.last_hash, 1])
 793                 print_log("blockchain reorg", self.height, block.get('previousblockhash'), self.last_hash)
 794                 self.import_block(block, self.last_hash, self.height, sync, revert=True)
 795                 self.pop_header()
 796                 self.flush_headers()
 797
 798                 self.height -= 1
 799
 800                 # read previous header from disk
 801                 self.header = self.read_header(self.height)
 802                 self.last_hash = self.hash_header(self.header)
 803
 804         self.header = self.block2header(self.bitcoind('getblock', [self.last_hash]))
 805
 806     def memorypool_update(self):
 807         mempool_hashes = self.bitcoind('getrawmempool')
 808
 809         for tx_hash in mempool_hashes:
 810             if tx_hash in self.mempool_hashes:
 811                 continue
 812
 813             tx = self.get_mempool_transaction(tx_hash)
 814             if not tx:
 815                 continue
 816
 817             for x in tx.get('inputs'):
 818                 txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 819                 try:
 820                     addr = self.db.Get(txi)
 821                 except:
 822                     continue
 823                 l = self.mempool_addresses.get(tx_hash, [])
 824                 if addr not in l:
 825                     l.append(addr)
 826                     self.mempool_addresses[tx_hash] = l
 827
 828             for x in tx.get('outputs'):
 829                 addr = x.get('address')
 830                 l = self.mempool_addresses.get(tx_hash, [])
 831                 if addr not in l:
 832                     l.append(addr)
 833                     self.mempool_addresses[tx_hash] = l
 834
 835             self.mempool_hashes.append(tx_hash)
 836
 837         # remove older entries from mempool_hashes
 838         self.mempool_hashes = mempool_hashes
 839
 840         # remove deprecated entries from mempool_addresses
 841         for tx_hash, addresses in self.mempool_addresses.items():
 842             if tx_hash not in self.mempool_hashes:
 843                 self.mempool_addresses.pop(tx_hash)
 844
 845         # rebuild mempool histories
 846         new_mempool_hist = {}
 847         for tx_hash, addresses in self.mempool_addresses.items():
 848             for addr in addresses:
 849                 h = new_mempool_hist.get(addr, [])
 850                 if tx_hash not in h:
 851                     h.append(tx_hash)
 852                 new_mempool_hist[addr] = h
 853
 854         # invalidate cache for mempool addresses whose mempool history has changed
 855         for addr in new_mempool_hist.keys():
 856             if addr in self.mempool_hist.keys():
 857                 if self.mempool_hist[addr] != new_mempool_hist[addr]:
 858                     self.invalidate_cache(addr)
 859             else:
 860                 self.invalidate_cache(addr)
 861
 862         # invalidate cache for addresses that are removed from mempool ?
 863         # this should not be necessary if they go into a block, but they might not
 864         for addr in self.mempool_hist.keys():
 865             if addr not in new_mempool_hist.keys():
 866                 self.invalidate_cache(addr)
 867
 868
 869         with self.mempool_lock:
 870             self.mempool_hist = new_mempool_hist
 871
 872     def invalidate_cache(self, address):
 873         with self.cache_lock:
 874             if address in self.history_cache:
 875                 print_log("cache: invalidating", address)
 876                 self.history_cache.pop(address)
 877
 878         if address in self.watched_addresses:
 879             self.address_queue.put(address)
 880
 881     def main_iteration(self):
 882         if self.shared.stopped():
 883             print_log("blockchain processor terminating")
 884             return
 885
 886         with self.dblock:
 887             t1 = time.time()
 888             self.catch_up()
 889             t2 = time.time()
 890
 891         self.memorypool_update()
 892         t3 = time.time()
 893         # print "mempool:", len(self.mempool_addresses), len(self.mempool_hist), "%.3fs"%(t3 - t2)
 894
 895         if self.sent_height != self.height:
 896             self.sent_height = self.height
 897             self.push_response({
 898                 'id': None,
 899                 'method': 'blockchain.numblocks.subscribe',
 900                 'params': [self.height],
 901             })
 902
 903         if self.sent_header != self.header:
 904             print_log("blockchain: %d (%.3fs)" % (self.height, t2 - t1))
 905             self.sent_header = self.header
 906             self.push_response({
 907                 'id': None,
 908                 'method': 'blockchain.headers.subscribe',
 909                 'params': [self.header],
 910             })
 911
 912         while True:
 913             try:
 914                 addr = self.address_queue.get(False)
 915             except:
 916                 break
 917             if addr in self.watched_addresses:
 918                 status = self.get_status(addr)
 919                 self.push_response({
 920                     'id': None,
 921                     'method': 'blockchain.address.subscribe',
 922                     'params': [addr, status],
 923                 })
 924
 925         if not self.shared.stopped():
 926             threading.Timer(10, self.main_iteration).start()
 927         else:
 928             print_log("blockchain processor terminating")