backends/bitcoind/blockchain_processor.py

   1 from json import dumps, loads
   2 import leveldb, urllib
   3 import deserialize
   4 import ast, time, threading, hashlib
   5 from Queue import Queue
   6 import traceback, sys, os
   7
   8
   9
  10 Hash = lambda x: hashlib.sha256(hashlib.sha256(x).digest()).digest()
  11 hash_encode = lambda x: x[::-1].encode('hex')
  12 hash_decode = lambda x: x.decode('hex')[::-1]
  13
  14
  15
  16 def rev_hex(s):
  17     return s.decode('hex')[::-1].encode('hex')
  18
  19
  20 def int_to_hex(i, length=1):
  21     s = hex(i)[2:].rstrip('L')
  22     s = "0"*(2*length - len(s)) + s
  23     return rev_hex(s)
  24
  25 def header_to_string(res):
  26     pbh = res.get('prev_block_hash')
  27     if pbh is None: pbh = '0'*64
  28     s = int_to_hex(res.get('version'),4) \
  29         + rev_hex(pbh) \
  30         + rev_hex(res.get('merkle_root')) \
  31         + int_to_hex(int(res.get('timestamp')),4) \
  32         + int_to_hex(int(res.get('bits')),4) \
  33         + int_to_hex(int(res.get('nonce')),4)
  34     return s
  35
  36 def header_from_string( s):
  37     hex_to_int = lambda s: eval('0x' + s[::-1].encode('hex'))
  38     h = {}
  39     h['version'] = hex_to_int(s[0:4])
  40     h['prev_block_hash'] = hash_encode(s[4:36])
  41     h['merkle_root'] = hash_encode(s[36:68])
  42     h['timestamp'] = hex_to_int(s[68:72])
  43     h['bits'] = hex_to_int(s[72:76])
  44     h['nonce'] = hex_to_int(s[76:80])
  45     return h
  46
  47
  48
  49
  50 from processor import Processor, print_log
  51
  52 class BlockchainProcessor(Processor):
  53
  54     def __init__(self, config, shared):
  55         Processor.__init__(self)
  56
  57         self.shared = shared
  58         self.up_to_date = False
  59         self.watched_addresses = []
  60         self.history_cache = {}
  61         self.chunk_cache = {}
  62         self.cache_lock = threading.Lock()
  63         self.headers_data = ''
  64
  65         self.mempool_addresses = {}
  66         self.mempool_hist = {}
  67         self.mempool_hashes = []
  68         self.mempool_lock = threading.Lock()
  69
  70         self.address_queue = Queue()
  71         self.dbpath = config.get('leveldb', 'path')
  72
  73         self.dblock = threading.Lock()
  74         try:
  75             self.db = leveldb.LevelDB(self.dbpath)
  76         except:
  77             traceback.print_exc(file=sys.stdout)
  78             self.shared.stop()
  79
  80         self.bitcoind_url = 'http://%s:%s@%s:%s/' % (
  81             config.get('bitcoind','user'),
  82             config.get('bitcoind','password'),
  83             config.get('bitcoind','host'),
  84             config.get('bitcoind','port'))
  85
  86         self.height = 0
  87         self.sent_height = 0
  88         self.sent_header = None
  89
  90
  91         try:
  92             hist = self.deserialize(self.db.Get('height'))
  93             self.last_hash, self.height, _ = hist[0]
  94             print_log( "hist", hist )
  95         except:
  96             #traceback.print_exc(file=sys.stdout)
  97             print_log('initializing database')
  98             self.height = 0
  99             self.last_hash = '000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'
 100
 101         # catch_up headers
 102         self.init_headers(self.height)
 103
 104         threading.Timer(0, lambda: self.catch_up(sync=False)).start()
 105         while not shared.stopped() and not self.up_to_date:
 106             try:
 107                 time.sleep(1)
 108             except:
 109                 print "keyboard interrupt: stopping threads"
 110                 shared.stop()
 111                 sys.exit(0)
 112
 113         print_log( "blockchain is up to date." )
 114
 115         threading.Timer(10, self.main_iteration).start()
 116
 117
 118
 119     def bitcoind(self, method, params=[]):
 120         postdata = dumps({"method": method, 'params': params, 'id':'jsonrpc'})
 121         respdata = urllib.urlopen(self.bitcoind_url, postdata).read()
 122         r = loads(respdata)
 123         if r['error'] != None:
 124             raise BaseException(r['error'])
 125         return r.get('result')
 126
 127
 128     def serialize(self, h):
 129         s = ''
 130         for txid, txpos, height in h:
 131             s += txid + int_to_hex(txpos, 4) + int_to_hex(height, 4)
 132         return s.decode('hex')
 133
 134
 135     def deserialize(self, s):
 136         h = []
 137         while s:
 138             txid = s[0:32].encode('hex')
 139             txpos = int( rev_hex( s[32:36].encode('hex') ), 16 )
 140             height = int( rev_hex( s[36:40].encode('hex') ), 16 )
 141             h.append( ( txid, txpos, height ) )
 142             s = s[40:]
 143         return h
 144
 145
 146     def block2header(self, b):
 147         return {"block_height":b.get('height'), "version":b.get('version'), "prev_block_hash":b.get('previousblockhash'),
 148                 "merkle_root":b.get('merkleroot'), "timestamp":b.get('time'), "bits":int(b.get('bits'),16), "nonce":b.get('nonce')}
 149
 150
 151     def get_header(self, height):
 152         block_hash = self.bitcoind('getblockhash', [height])
 153         b = self.bitcoind('getblock', [block_hash])
 154         return self.block2header(b)
 155
 156
 157     def init_headers(self, db_height):
 158         self.chunk_cache = {}
 159         self.headers_filename = os.path.join( self.dbpath, 'blockchain_headers')
 160
 161         if os.path.exists(self.headers_filename):
 162             height = os.path.getsize(self.headers_filename)/80 - 1   # the current height
 163             if height > 0:
 164                 prev_hash = self.hash_header(self.read_header(height))
 165             else:
 166                 prev_hash = None
 167         else:
 168             open(self.headers_filename,'wb').close()
 169             prev_hash = None
 170             height = -1
 171
 172         if height < db_height:
 173             print_log( "catching up missing headers:", height, db_height)
 174
 175         try:
 176             while height != db_height:
 177                 height = height + 1
 178                 header = self.get_header(height)
 179                 if height>1:
 180                     assert prev_hash == header.get('prev_block_hash')
 181                 self.write_header(header, sync=False)
 182                 prev_hash = self.hash_header(header)
 183                 if height%1000==0: print_log("headers file:",height)
 184         except KeyboardInterrupt:
 185             self.flush_headers()
 186             sys.exit()
 187
 188         self.flush_headers()
 189
 190
 191     def hash_header(self, header):
 192         return rev_hex(Hash(header_to_string(header).decode('hex')).encode('hex'))
 193
 194
 195     def read_header(self, block_height):
 196         if os.path.exists(self.headers_filename):
 197             f = open(self.headers_filename,'rb')
 198             f.seek(block_height*80)
 199             h = f.read(80)
 200             f.close()
 201             if len(h) == 80:
 202                 h = header_from_string(h)
 203                 return h
 204
 205
 206     def read_chunk(self, index):
 207         f = open(self.headers_filename,'rb')
 208         f.seek(index*2016*80)
 209         chunk = f.read(2016*80)
 210         f.close()
 211         return chunk.encode('hex')
 212
 213
 214     def write_header(self, header, sync=True):
 215         if not self.headers_data:
 216             self.headers_offset = header.get('block_height')
 217
 218         self.headers_data += header_to_string(header).decode('hex')
 219         if sync or len(self.headers_data) > 40*100:
 220             self.flush_headers()
 221
 222     def pop_header(self):
 223         # we need to do this only if we have not flushed
 224         if self.headers_data:
 225             self.headers_data = self.headers_data[:-40]
 226
 227     def flush_headers(self):
 228         if not self.headers_data: return
 229         f = open(self.headers_filename,'rb+')
 230         f.seek(self.headers_offset*80)
 231         f.write(self.headers_data)
 232         f.close()
 233         self.headers_data = ''
 234
 235
 236     def get_chunk(self, i):
 237         # store them on disk; store the current chunk in memory
 238         chunk = self.chunk_cache.get(i)
 239         if not chunk:
 240             chunk = self.read_chunk(i)
 241             self.chunk_cache[i] = chunk
 242         return chunk
 243
 244
 245     def get_transaction(self, txid, block_height=-1, is_coinbase = False):
 246         raw_tx = self.bitcoind('getrawtransaction', [txid, 0, block_height])
 247         vds = deserialize.BCDataStream()
 248         vds.write(raw_tx.decode('hex'))
 249         out = deserialize.parse_Transaction(vds, is_coinbase)
 250         return out
 251
 252
 253     def get_history(self, addr, cache_only=False):
 254         with self.cache_lock: hist = self.history_cache.get( addr )
 255         if hist is not None: return hist
 256         if cache_only: 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         # should not be necessary
 267         hist.sort( key=lambda tup: tup[1])
 268         # check uniqueness too...
 269
 270         # add memory pool
 271         with self.mempool_lock:
 272             for txid in self.mempool_hist.get(addr,[]):
 273                 hist.append((txid, 0, 0))
 274
 275         hist = map(lambda x: {'tx_hash':x[0], 'height':x[2]}, hist)
 276         # add something to distinguish between unused and empty addresses
 277         if hist == [] and is_known: hist = ['*']
 278
 279         with self.cache_lock: self.history_cache[addr] = hist
 280         return hist
 281
 282
 283     def get_status(self, addr, cache_only=False):
 284         tx_points = self.get_history(addr, cache_only)
 285         if cache_only and tx_points == -1: return -1
 286
 287         if not tx_points: return None
 288         if tx_points == ['*']: return '*'
 289         status = ''
 290         for tx in tx_points:
 291             status += tx.get('tx_hash') + ':%d:' % tx.get('height')
 292         return hashlib.sha256( status ).digest().encode('hex')
 293
 294
 295     def get_merkle(self, tx_hash, height):
 296
 297         block_hash = self.bitcoind('getblockhash', [height])
 298         b = self.bitcoind('getblock', [block_hash])
 299         tx_list = b.get('tx')
 300         tx_pos = tx_list.index(tx_hash)
 301
 302         merkle = map(hash_decode, tx_list)
 303         target_hash = hash_decode(tx_hash)
 304         s = []
 305         while len(merkle) != 1:
 306             if len(merkle)%2: merkle.append( merkle[-1] )
 307             n = []
 308             while merkle:
 309                 new_hash = Hash( merkle[0] + merkle[1] )
 310                 if merkle[0] == target_hash:
 311                     s.append( hash_encode( merkle[1]))
 312                     target_hash = new_hash
 313                 elif merkle[1] == target_hash:
 314                     s.append( hash_encode( merkle[0]))
 315                     target_hash = new_hash
 316                 n.append( new_hash )
 317                 merkle = merkle[2:]
 318             merkle = n
 319
 320         return {"block_height":height, "merkle":s, "pos":tx_pos}
 321
 322
 323
 324
 325     def add_to_history(self, addr, tx_hash, tx_pos, tx_height):
 326
 327         # keep it sorted
 328         s = (tx_hash + int_to_hex(tx_pos, 4) + int_to_hex(tx_height, 4)).decode('hex')
 329
 330         serialized_hist = self.batch_list[addr]
 331
 332         l = len(serialized_hist)/40
 333         for i in range(l-1, -1, -1):
 334             item = serialized_hist[40*i:40*(i+1)]
 335             item_height = int( rev_hex( item[36:40].encode('hex') ), 16 )
 336             if item_height < tx_height:
 337                 serialized_hist = serialized_hist[0:40*(i+1)] + s + serialized_hist[40*(i+1):]
 338                 break
 339         else:
 340             serialized_hist = s + serialized_hist
 341
 342         self.batch_list[addr] = serialized_hist
 343
 344         # backlink
 345         txo = (tx_hash + int_to_hex(tx_pos, 4)).decode('hex')
 346         self.batch_txio[txo] = addr
 347
 348
 349     def remove_from_history(self, tx_hash, tx_pos):
 350
 351         txi = (tx_hash + int_to_hex(tx_pos, 4)).decode('hex')
 352         try:
 353             addr = self.batch_txio[txi]
 354         except:
 355             raise BaseException(tx_hash, tx_pos)
 356             print "WARNING: cannot find address for", (tx_hash, tx_pos)
 357             return
 358
 359         serialized_hist = self.batch_list[addr]
 360
 361         l = len(serialized_hist)/40
 362         for i in range(l):
 363             if serialized_hist[40*i:40*i+36] == txi:
 364                 serialized_hist = serialized_hist[0:40*i] + serialized_hist[40*(i+1):]
 365                 break
 366         else:
 367             raise BaseException("prevout not found", addr, hist, tx_hash, tx_pos)
 368         self.batch_list[addr] = serialized_hist
 369
 370
 371     def deserialize_block(self, block):
 372         txlist = block.get('tx')
 373         tx_hashes = []  # ordered txids
 374         txdict = {}     # deserialized tx
 375         is_coinbase = True
 376         for raw_tx in txlist:
 377             tx_hash = hash_encode(Hash(raw_tx.decode('hex')))
 378             tx_hashes.append(tx_hash)
 379             vds = deserialize.BCDataStream()
 380             vds.write(raw_tx.decode('hex'))
 381             tx = deserialize.parse_Transaction(vds, is_coinbase)
 382             txdict[tx_hash] = tx
 383             is_coinbase = False
 384         return tx_hashes, txdict
 385
 386
 387     def import_block(self, block, block_hash, block_height, sync, revert=False):
 388
 389         self.batch_list = {}  # address -> history
 390         self.batch_txio = {}  # transaction i/o -> address
 391
 392         inputs_to_read = []
 393         addr_to_read = []
 394
 395         # deserialize transactions
 396         t0 = time.time()
 397         tx_hashes, txdict = self.deserialize_block(block)
 398
 399         t00 = time.time()
 400
 401         if revert:
 402             # read addresses of tx outputs
 403             for tx_hash, tx in txdict.items():
 404                 for x in tx.get('outputs'):
 405                     txo = (tx_hash + int_to_hex(x.get('index'), 4)).decode('hex')
 406                 self.batch_txio[txo] = x.get('address')
 407         else:
 408             # read addresses of tx inputs
 409             for tx in txdict.values():
 410                 for x in tx.get('inputs'):
 411                     txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 412                     inputs_to_read.append(txi)
 413
 414             inputs_to_read.sort()
 415             for txi in inputs_to_read:
 416                 try:
 417                     addr = self.db.Get(txi)
 418                 except:
 419                     # the input could come from the same block
 420                     continue
 421                 self.batch_txio[txi] = addr
 422                 addr_to_read.append(addr)
 423
 424
 425         # read histories of addresses
 426         for txid, tx in txdict.items():
 427             for x in tx.get('outputs'):
 428                 addr_to_read.append(x.get('address'))
 429
 430         addr_to_read.sort()
 431         for addr in addr_to_read:
 432             try:
 433                 self.batch_list[addr] = self.db.Get(addr)
 434             except:
 435                 self.batch_list[addr] = ''
 436
 437         # process
 438         t1 = time.time()
 439
 440         for txid in tx_hashes: # must be ordered
 441             tx = txdict[txid]
 442             if not revert:
 443                 for x in tx.get('inputs'):
 444                     self.remove_from_history( x.get('prevout_hash'), x.get('prevout_n'))
 445                 for x in tx.get('outputs'):
 446                     self.add_to_history( x.get('address'), txid, x.get('index'), block_height)
 447             else:
 448                 for x in tx.get('outputs'):
 449                     self.remove_from_history( txid, x.get('index'))
 450
 451                 for x in tx.get('inputs'):
 452                     prevout_height = self.db.Get(x['prevout_hash'].decode('hex'))
 453                     try:
 454                         # note: this will fail if the block containing txi is part of the reorg and has been orphaned by bitcoind
 455                         txi = self.get_transaction(x.get('prevout_hash'), prevout_height )
 456                     except:
 457                         # so, if if it fails, we need to read the block containing txi
 458                         prevout_block_hash = self.db.Get('%d'%prevout_height)
 459                         prevout_block = self.bitcoind('getblock', [prevout_block_hash, 1])
 460                         for txc in prevout_block['tx']:
 461                             if hash_encode(Hash(txc)) == prevout_hash:
 462                                 raw_txi = txc
 463                                 break
 464                         else:
 465                             raise BaseException('txi not found')
 466
 467                         vds = deserialize.BCDataStream()
 468                         vds.write(raw_txi.decode('hex'))
 469                         txi = deserialize.parse_Transaction(vds, False)
 470
 471                     print "txi", txi
 472                     output = txi.get('outputs')[x.get('prevout_n')]
 473                     prevout_addr = output['address']
 474                     self.batch_list[prevout_addr] = self.db.Get(prevout_addr)
 475                     # no longer chronological..
 476                     self.add_to_history( prevout_addr, x.get('prevout_hash'), x.get('prevout_n'), prevout_height)
 477                     print "new hist", self.deserialize(self.batch_list[prevout_addr])
 478
 479         # write
 480         max_len = 0
 481         max_addr = ''
 482         t2 = time.time()
 483
 484         batch = leveldb.WriteBatch()
 485         for addr, serialized_hist in self.batch_list.items():
 486             batch.Put(addr, serialized_hist)
 487             l = len(serialized_hist)
 488             if l > max_len:
 489                 max_len = l
 490                 max_addr = addr
 491
 492         for txio, addr in self.batch_txio.items():
 493             batch.Put(txio, addr)
 494         # delete spent inputs
 495         for txi in inputs_to_read:
 496             batch.Delete(txi)
 497
 498         # add tx -> height
 499         for txid in tx_hashes:
 500             batch.Put(txid.decode('hex'), "%d"%block_height)
 501         # add height -> block_hash
 502         batch.Put("%d"%block_height, block_hash)
 503         # add the max
 504         batch.Put('height', self.serialize( [(block_hash, block_height, 0)] ) )
 505
 506         # actual write
 507         self.db.Write(batch, sync = sync)
 508
 509         t3 = time.time()
 510         if t3 - t0 > 10 and not sync:
 511             print_log("block", block_height,
 512                       "parse:%0.2f "%(t00 - t0),
 513                       "read:%0.2f "%(t1 - t00),
 514                       "proc:%.2f "%(t2-t1),
 515                       "write:%.2f "%(t3-t2),
 516                       "max:", max_len, max_addr)
 517
 518         for addr in self.batch_list.keys(): self.invalidate_cache(addr)
 519
 520
 521
 522     def add_request(self, request):
 523         # see if we can get if from cache. if not, add to queue
 524         if self.process( request, cache_only = True) == -1:
 525             self.queue.put(request)
 526
 527
 528
 529     def process(self, request, cache_only = False):
 530         #print "abe process", request
 531
 532         message_id = request['id']
 533         method = request['method']
 534         params = request.get('params',[])
 535         result = None
 536         error = None
 537
 538         if method == 'blockchain.numblocks.subscribe':
 539             result = self.height
 540
 541         elif method == 'blockchain.headers.subscribe':
 542             result = self.header
 543
 544         elif method == 'blockchain.address.subscribe':
 545             try:
 546                 address = params[0]
 547                 result = self.get_status(address, cache_only)
 548                 self.watch_address(address)
 549             except BaseException, e:
 550                 error = str(e) + ': ' + address
 551                 print_log( "error:", error )
 552
 553         elif method == 'blockchain.address.subscribe2':
 554             try:
 555                 address = params[0]
 556                 result = self.get_status(address, cache_only)
 557                 self.watch_address(address)
 558             except BaseException, e:
 559                 error = str(e) + ': ' + address
 560                 print_log( "error:", error )
 561
 562         elif method == 'blockchain.address.get_history2':
 563             try:
 564                 address = params[0]
 565                 result = self.get_history( address, cache_only )
 566             except BaseException, e:
 567                 error = str(e) + ': ' + address
 568                 print_log( "error:", error )
 569
 570         elif method == 'blockchain.block.get_header':
 571             if cache_only:
 572                 result = -1
 573             else:
 574                 try:
 575                     height = params[0]
 576                     result = self.get_header( height )
 577                 except BaseException, e:
 578                     error = str(e) + ': %d'% height
 579                     print_log( "error:", error )
 580
 581         elif method == 'blockchain.block.get_chunk':
 582             if cache_only:
 583                 result = -1
 584             else:
 585                 try:
 586                     index = params[0]
 587                     result = self.get_chunk( index )
 588                 except BaseException, e:
 589                     error = str(e) + ': %d'% index
 590                     print_log( "error:", error)
 591
 592         elif method == 'blockchain.transaction.broadcast':
 593             txo = self.bitcoind('sendrawtransaction', params)
 594             print_log( "sent tx:", txo )
 595             result = txo
 596
 597         elif method == 'blockchain.transaction.get_merkle':
 598             if cache_only:
 599                 result = -1
 600             else:
 601                 try:
 602                     tx_hash = params[0]
 603                     tx_height = params[1]
 604                     result = self.get_merkle(tx_hash, tx_height)
 605                 except BaseException, e:
 606                     error = str(e) + ': ' + tx_hash
 607                     print_log( "error:", error )
 608
 609         elif method == 'blockchain.transaction.get':
 610             try:
 611                 tx_hash = params[0]
 612                 height = params[1]
 613                 result = self.bitcoind('getrawtransaction', [tx_hash, 0, height] )
 614             except BaseException, e:
 615                 error = str(e) + ': ' + tx_hash
 616                 print_log( "error:", error )
 617
 618         else:
 619             error = "unknown method:%s"%method
 620
 621         if cache_only and result == -1: return -1
 622
 623         if error:
 624             response = { 'id':message_id, 'error':error }
 625             self.push_response(response)
 626         elif result != '':
 627             response = { 'id':message_id, 'result':result }
 628             self.push_response(response)
 629
 630
 631     def watch_address(self, addr):
 632         if addr not in self.watched_addresses:
 633             self.watched_addresses.append(addr)
 634
 635
 636
 637     def catch_up(self, sync = True):
 638         #   a reorg in bitcoind id not synchronous with my database
 639         #
 640         #                     -------> F ------> G -------> H
 641         #                    /
 642         #                   /
 643         #        A ------> B --------> C ------> E
 644         #
 645         #        we always compare the hash in the headers file to the hash returned by bitcoind
 646
 647
 648         t1 = time.time()
 649
 650         while not self.shared.stopped():
 651
 652             # are we done yet?
 653             info = self.bitcoind('getinfo')
 654             bitcoind_height = info.get('blocks')
 655             bitcoind_block_hash = self.bitcoind('getblockhash', [bitcoind_height])
 656             if self.last_hash == bitcoind_block_hash:
 657                 self.up_to_date = True
 658                 break
 659
 660             # not done..
 661             self.up_to_date = False
 662             next_block_hash = self.bitcoind('getblockhash', [self.height+1])
 663             next_block = self.bitcoind('getblock', [next_block_hash, 1])
 664
 665             if next_block.get('previousblockhash') == self.last_hash:
 666
 667                 self.import_block(next_block, next_block_hash, self.height+1, sync)
 668                 self.height = self.height + 1
 669                 self.write_header(self.block2header(next_block), sync)
 670                 self.last_hash = next_block_hash
 671
 672                 if (self.height)%100 == 0 and not sync:
 673                     t2 = time.time()
 674                     print_log( "catch_up: block %d (%.3fs)"%( self.height, t2 - t1 ) )
 675                     t1 = t2
 676
 677             else:
 678                 # revert current block
 679                 block = self.bitcoind('getblock', [self.last_hash, 1])
 680                 print_log( "bc2: reorg", self.height, block.get('previousblockhash'), self.last_hash )
 681                 self.import_block(block, self.last_hash, self.height, sync, revert=True)
 682                 self.pop_header()
 683
 684                 self.height = self.height -1
 685
 686                 # read previous header from disk
 687                 self.header = self.read_header(self.height)
 688                 self.last_hash = self.hash_header(self.header)
 689
 690
 691         self.header = self.block2header(self.bitcoind('getblock', [self.last_hash]))
 692
 693
 694
 695
 696     def memorypool_update(self):
 697
 698         mempool_hashes = self.bitcoind('getrawmempool')
 699
 700         for tx_hash in mempool_hashes:
 701             if tx_hash in self.mempool_hashes: continue
 702
 703             tx = self.get_transaction(tx_hash)
 704             if not tx: continue
 705
 706             for x in tx.get('inputs'):
 707                 txi = (x.get('prevout_hash') + int_to_hex(x.get('prevout_n'), 4)).decode('hex')
 708                 try:
 709                     addr = self.db.Get(txi)
 710                 except:
 711                     continue
 712                 l = self.mempool_addresses.get(tx_hash, [])
 713                 if addr not in l:
 714                     l.append( addr )
 715                     self.mempool_addresses[tx_hash] = l
 716
 717             for x in tx.get('outputs'):
 718                 addr = x.get('address')
 719                 l = self.mempool_addresses.get(tx_hash, [])
 720                 if addr not in l:
 721                     l.append( addr )
 722                     self.mempool_addresses[tx_hash] = l
 723
 724             self.mempool_hashes.append(tx_hash)
 725
 726         # remove older entries from mempool_hashes
 727         self.mempool_hashes = mempool_hashes
 728
 729         # remove deprecated entries from mempool_addresses
 730         for tx_hash, addresses in self.mempool_addresses.items():
 731             if tx_hash not in self.mempool_hashes:
 732                 self.mempool_addresses.pop(tx_hash)
 733
 734         # rebuild histories
 735         new_mempool_hist = {}
 736         for tx_hash, addresses in self.mempool_addresses.items():
 737             for addr in addresses:
 738                 h = new_mempool_hist.get(addr, [])
 739                 if tx_hash not in h:
 740                     h.append( tx_hash )
 741                 new_mempool_hist[addr] = h
 742
 743         for addr in new_mempool_hist.keys():
 744             if addr in self.mempool_hist.keys():
 745                 if self.mempool_hist[addr] != new_mempool_hist[addr]:
 746                     self.invalidate_cache(addr)
 747             else:
 748                 self.invalidate_cache(addr)
 749
 750         with self.mempool_lock:
 751             self.mempool_hist = new_mempool_hist
 752
 753
 754
 755     def invalidate_cache(self, address):
 756         with self.cache_lock:
 757             if self.history_cache.has_key(address):
 758                 print_log( "cache: invalidating", address )
 759                 self.history_cache.pop(address)
 760
 761         if address in self.watched_addresses:
 762             self.address_queue.put(address)
 763
 764
 765
 766     def main_iteration(self):
 767
 768         if self.shared.stopped():
 769             print_log( "blockchain processor terminating" )
 770             return
 771
 772         with self.dblock:
 773             t1 = time.time()
 774             self.catch_up()
 775             t2 = time.time()
 776
 777         self.memorypool_update()
 778         t3 = time.time()
 779         # print "mempool:", len(self.mempool_addresses), len(self.mempool_hist), "%.3fs"%(t3 - t2)
 780
 781
 782         if self.sent_height != self.height:
 783             self.sent_height = self.height
 784             self.push_response({ 'id': None, 'method':'blockchain.numblocks.subscribe', 'params':[self.height] })
 785
 786         if self.sent_header != self.header:
 787             print_log( "blockchain: %d (%.3fs)"%( self.height, t2 - t1 ) )
 788             self.sent_header = self.header
 789             self.push_response({ 'id': None, 'method':'blockchain.headers.subscribe', 'params':[self.header] })
 790
 791         while True:
 792             try:
 793                 addr = self.address_queue.get(False)
 794             except:
 795                 break
 796             if addr in self.watched_addresses:
 797                 status = self.get_status( addr )
 798                 self.push_response({ 'id': None, 'method':'blockchain.address.subscribe', 'params':[addr, status] })
 799                 self.push_response({ 'id': None, 'method':'blockchain.address.subscribe2', 'params':[addr, status] })
 800
 801
 802         if not self.shared.stopped():
 803             threading.Timer(10, self.main_iteration).start()
 804         else:
 805             print_log( "blockchain processor terminating" )
 806
 807
 808
 809