apt_dht_Khashmir/DHT.py

   1
   2 from datetime import datetime
   3 import os, sha, random
   4
   5 from twisted.internet import defer, reactor
   6 from twisted.internet.abstract import isIPAddress
   7 from twisted.python import log
   8 from twisted.trial import unittest
   9 from zope.interface import implements
  10
  11 from apt_dht.interfaces import IDHT
  12 from khashmir import Khashmir
  13 from bencode import bencode, bdecode
  14
  15 khashmir_dir = 'apt-dht-Khashmir'
  16
  17 class DHTError(Exception):
  18     """Represents errors that occur in the DHT."""
  19
  20 class DHT:
  21
  22     implements(IDHT)
  23
  24     def __init__(self):
  25         self.config = None
  26         self.cache_dir = ''
  27         self.bootstrap = []
  28         self.bootstrap_node = False
  29         self.joining = None
  30         self.joined = False
  31         self.outstandingJoins = 0
  32         self.foundAddrs = []
  33         self.storing = {}
  34         self.retrieving = {}
  35         self.retrieved = {}
  36
  37     def loadConfig(self, config, section):
  38         """See L{apt_dht.interfaces.IDHT}."""
  39         self.config_parser = config
  40         self.section = section
  41         self.config = {}
  42         self.cache_dir = os.path.join(self.config_parser.get(section, 'cache_dir'), khashmir_dir)
  43         if not os.path.exists(self.cache_dir):
  44             os.makedirs(self.cache_dir)
  45         self.bootstrap = self.config_parser.getstringlist(section, 'BOOTSTRAP')
  46         self.bootstrap_node = self.config_parser.getboolean(section, 'BOOTSTRAP_NODE')
  47         for k in self.config_parser.options(section):
  48             if k in ['K', 'HASH_LENGTH', 'CONCURRENT_REQS', 'STORE_REDUNDANCY',
  49                      'RETRIEVE_VALUES', 'MAX_FAILURES', 'PORT']:
  50                 self.config[k] = self.config_parser.getint(section, k)
  51             elif k in ['CHECKPOINT_INTERVAL', 'MIN_PING_INTERVAL',
  52                        'BUCKET_STALENESS', 'KEY_EXPIRE']:
  53                 self.config[k] = self.config_parser.gettime(section, k)
  54             elif k in ['SPEW']:
  55                 self.config[k] = self.config_parser.getboolean(section, k)
  56             else:
  57                 self.config[k] = self.config_parser.get(section, k)
  58
  59     def join(self):
  60         """See L{apt_dht.interfaces.IDHT}."""
  61         if self.config is None:
  62             raise DHTError, "configuration not loaded"
  63         if self.joining:
  64             raise DHTError, "a join is already in progress"
  65
  66         self.khashmir = Khashmir(self.config, self.cache_dir)
  67
  68         self.joining = defer.Deferred()
  69         for node in self.bootstrap:
  70             host, port = node.rsplit(':', 1)
  71             port = int(port)
  72             if isIPAddress(host):
  73                 self._join_gotIP(host, port)
  74             else:
  75                 reactor.resolve(host).addCallback(self._join_gotIP, port)
  76
  77         return self.joining
  78
  79     def _join_gotIP(self, ip, port):
  80         """Called after an IP address has been found for a single bootstrap node."""
  81         self.outstandingJoins += 1
  82         self.khashmir.addContact(ip, port, self._join_single, self._join_error)
  83
  84     def _join_single(self, addr):
  85         """Called when a single bootstrap node has been added."""
  86         self.outstandingJoins -= 1
  87         if addr:
  88             self.foundAddrs.append(addr)
  89         if addr or self.outstandingJoins <= 0:
  90             self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
  91         log.msg('Got back from bootstrap node: %r' % (addr,))
  92
  93     def _join_error(self, failure = None):
  94         """Called when a single bootstrap node has failed."""
  95         self.outstandingJoins -= 1
  96         log.msg("bootstrap node could not be reached")
  97         if self.outstandingJoins <= 0:
  98             self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
  99
 100     def _join_complete(self, result):
 101         """Called when the tables have been initialized with nodes."""
 102         if not self.joined and len(result) > 0:
 103             self.joined = True
 104         if self.joining and self.outstandingJoins <= 0:
 105             df = self.joining
 106             self.joining = None
 107             if self.joined or self.bootstrap_node:
 108                 self.joined = True
 109                 df.callback(self.foundAddrs)
 110             else:
 111                 df.errback(DHTError('could not find any nodes to bootstrap to'))
 112
 113     def getAddrs(self):
 114         return self.foundAddrs
 115
 116     def leave(self):
 117         """See L{apt_dht.interfaces.IDHT}."""
 118         if self.config is None:
 119             raise DHTError, "configuration not loaded"
 120
 121         if self.joined or self.joining:
 122             if self.joining:
 123                 self.joining.errback(DHTError('still joining when leave was called'))
 124                 self.joining = None
 125             self.joined = False
 126             self.khashmir.shutdown()
 127
 128     def _normKey(self, key, bits=None, bytes=None):
 129         bits = self.config["HASH_LENGTH"]
 130         if bits is not None:
 131             bytes = (bits - 1) // 8 + 1
 132         else:
 133             if bytes is None:
 134                 raise DHTError, "you must specify one of bits or bytes for normalization"
 135         if len(key) < bytes:
 136             key = key + '\000'*(bytes - len(key))
 137         elif len(key) > bytes:
 138             key = key[:bytes]
 139         return key
 140
 141     def getValue(self, key):
 142         """See L{apt_dht.interfaces.IDHT}."""
 143         if self.config is None:
 144             raise DHTError, "configuration not loaded"
 145         if not self.joined:
 146             raise DHTError, "have not joined a network yet"
 147
 148         key = self._normKey(key)
 149
 150         d = defer.Deferred()
 151         if key not in self.retrieving:
 152             self.khashmir.valueForKey(key, self._getValue)
 153         self.retrieving.setdefault(key, []).append(d)
 154         return d
 155
 156     def _getValue(self, key, result):
 157         if result:
 158             self.retrieved.setdefault(key, []).extend([bdecode(r) for r in result])
 159         else:
 160             final_result = []
 161             if key in self.retrieved:
 162                 final_result = self.retrieved[key]
 163                 del self.retrieved[key]
 164             for i in range(len(self.retrieving[key])):
 165                 d = self.retrieving[key].pop(0)
 166                 d.callback(final_result)
 167             del self.retrieving[key]
 168
 169     def storeValue(self, key, value):
 170         """See L{apt_dht.interfaces.IDHT}."""
 171         if self.config is None:
 172             raise DHTError, "configuration not loaded"
 173         if not self.joined:
 174             raise DHTError, "have not joined a network yet"
 175
 176         key = self._normKey(key)
 177         bvalue = bencode(value)
 178
 179         if key in self.storing and bvalue in self.storing[key]:
 180             raise DHTError, "already storing that key with the same value"
 181
 182         d = defer.Deferred()
 183         self.khashmir.storeValueForKey(key, bvalue, self._storeValue)
 184         self.storing.setdefault(key, {})[bvalue] = d
 185         return d
 186
 187     def _storeValue(self, key, bvalue, result):
 188         if key in self.storing and bvalue in self.storing[key]:
 189             if len(result) > 0:
 190                 self.storing[key][bvalue].callback(result)
 191             else:
 192                 self.storing[key][bvalue].errback(DHTError('could not store value %s in key %s' % (bvalue, key)))
 193             del self.storing[key][bvalue]
 194             if len(self.storing[key].keys()) == 0:
 195                 del self.storing[key]
 196
 197 class TestSimpleDHT(unittest.TestCase):
 198     """Unit tests for the DHT."""
 199
 200     timeout = 2
 201     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 202                     'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
 203                     'STORE_REDUNDANCY': 3, 'RETRIEVE_VALUES': -10000,
 204                     'MAX_FAILURES': 3,
 205                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 206                     'KEY_EXPIRE': 3600, 'SPEW': False, }
 207
 208     def setUp(self):
 209         self.a = DHT()
 210         self.b = DHT()
 211         self.a.config = self.DHT_DEFAULTS.copy()
 212         self.a.config['PORT'] = 4044
 213         self.a.bootstrap = ["127.0.0.1:4044"]
 214         self.a.bootstrap_node = True
 215         self.a.cache_dir = '/tmp'
 216         self.b.config = self.DHT_DEFAULTS.copy()
 217         self.b.config['PORT'] = 4045
 218         self.b.bootstrap = ["127.0.0.1:4044"]
 219         self.b.cache_dir = '/tmp'
 220
 221     def test_bootstrap_join(self):
 222         d = self.a.join()
 223         return d
 224
 225     def node_join(self, result):
 226         d = self.b.join()
 227         return d
 228
 229     def test_join(self):
 230         self.lastDefer = defer.Deferred()
 231         d = self.a.join()
 232         d.addCallback(self.node_join)
 233         d.addCallback(self.lastDefer.callback)
 234         return self.lastDefer
 235
 236     def test_normKey(self):
 237         h = self.a._normKey('12345678901234567890')
 238         self.failUnless(h == '12345678901234567890')
 239         h = self.a._normKey('12345678901234567')
 240         self.failUnless(h == '12345678901234567\000\000\000')
 241         h = self.a._normKey('1234567890123456789012345')
 242         self.failUnless(h == '12345678901234567890')
 243         h = self.a._normKey('1234567890123456789')
 244         self.failUnless(h == '1234567890123456789\000')
 245         h = self.a._normKey('123456789012345678901')
 246         self.failUnless(h == '12345678901234567890')
 247
 248     def value_stored(self, result, value):
 249         self.stored -= 1
 250         if self.stored == 0:
 251             self.get_values()
 252
 253     def store_values(self, result):
 254         self.stored = 3
 255         d = self.a.storeValue(sha.new('4045').digest(), str(4045*3))
 256         d.addCallback(self.value_stored, 4045)
 257         d = self.a.storeValue(sha.new('4044').digest(), str(4044*2))
 258         d.addCallback(self.value_stored, 4044)
 259         d = self.b.storeValue(sha.new('4045').digest(), str(4045*2))
 260         d.addCallback(self.value_stored, 4045)
 261
 262     def check_values(self, result, values):
 263         self.checked -= 1
 264         self.failUnless(len(result) == len(values))
 265         for v in result:
 266             self.failUnless(v in values)
 267         if self.checked == 0:
 268             self.lastDefer.callback(1)
 269
 270     def get_values(self):
 271         self.checked = 4
 272         d = self.a.getValue(sha.new('4044').digest())
 273         d.addCallback(self.check_values, [str(4044*2)])
 274         d = self.b.getValue(sha.new('4044').digest())
 275         d.addCallback(self.check_values, [str(4044*2)])
 276         d = self.a.getValue(sha.new('4045').digest())
 277         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 278         d = self.b.getValue(sha.new('4045').digest())
 279         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 280
 281     def test_store(self):
 282         from twisted.internet.base import DelayedCall
 283         DelayedCall.debug = True
 284         self.lastDefer = defer.Deferred()
 285         d = self.a.join()
 286         d.addCallback(self.node_join)
 287         d.addCallback(self.store_values)
 288         return self.lastDefer
 289
 290     def tearDown(self):
 291         self.a.leave()
 292         try:
 293             os.unlink(self.a.khashmir.store.db)
 294         except:
 295             pass
 296         self.b.leave()
 297         try:
 298             os.unlink(self.b.khashmir.store.db)
 299         except:
 300             pass
 301
 302 class TestMultiDHT(unittest.TestCase):
 303
 304     timeout = 60
 305     num = 20
 306     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 307                     'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
 308                     'STORE_REDUNDANCY': 3, 'RETRIEVE_VALUES': -10000,
 309                     'MAX_FAILURES': 3,
 310                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 311                     'KEY_EXPIRE': 3600, 'SPEW': False, }
 312
 313     def setUp(self):
 314         self.l = []
 315         self.startport = 4081
 316         for i in range(self.num):
 317             self.l.append(DHT())
 318             self.l[i].config = self.DHT_DEFAULTS.copy()
 319             self.l[i].config['PORT'] = self.startport + i
 320             self.l[i].bootstrap = ["127.0.0.1:" + str(self.startport)]
 321             self.l[i].cache_dir = '/tmp'
 322         self.l[0].bootstrap_node = True
 323
 324     def node_join(self, result, next_node):
 325         d = self.l[next_node].join()
 326         if next_node + 1 < len(self.l):
 327             d.addCallback(self.node_join, next_node + 1)
 328         else:
 329             d.addCallback(self.lastDefer.callback)
 330
 331     def test_join(self):
 332         self.timeout = 2
 333         self.lastDefer = defer.Deferred()
 334         d = self.l[0].join()
 335         d.addCallback(self.node_join, 1)
 336         return self.lastDefer
 337
 338     def store_values(self, result, i = 0, j = 0):
 339         if j > i:
 340             j -= i+1
 341             i += 1
 342         if i == len(self.l):
 343             self.get_values()
 344         else:
 345             d = self.l[j].storeValue(sha.new(str(self.startport+i)).digest(), str((self.startport+i)*(j+1)))
 346             d.addCallback(self.store_values, i, j+1)
 347
 348     def get_values(self, result = None, check = None, i = 0, j = 0):
 349         if result is not None:
 350             self.failUnless(len(result) == len(check))
 351             for v in result:
 352                 self.failUnless(v in check)
 353         if j >= len(self.l):
 354             j -= len(self.l)
 355             i += 1
 356         if i == len(self.l):
 357             self.lastDefer.callback(1)
 358         else:
 359             d = self.l[i].getValue(sha.new(str(self.startport+j)).digest())
 360             check = []
 361             for k in range(self.startport+j, (self.startport+j)*(j+1)+1, self.startport+j):
 362                 check.append(str(k))
 363             d.addCallback(self.get_values, check, i, j + random.randrange(1, min(len(self.l), 10)))
 364
 365     def store_join(self, result, next_node):
 366         d = self.l[next_node].join()
 367         if next_node + 1 < len(self.l):
 368             d.addCallback(self.store_join, next_node + 1)
 369         else:
 370             d.addCallback(self.store_values)
 371
 372     def test_store(self):
 373         from twisted.internet.base import DelayedCall
 374         DelayedCall.debug = True
 375         self.lastDefer = defer.Deferred()
 376         d = self.l[0].join()
 377         d.addCallback(self.store_join, 1)
 378         return self.lastDefer
 379
 380     def tearDown(self):
 381         for i in self.l:
 382             try:
 383                 i.leave()
 384                 os.unlink(i.khashmir.store.db)
 385             except:
 386                 pass