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
  14 khashmir_dir = 'apt-dht-Khashmir'
  15
  16 class DHTError(Exception):
  17     """Represents errors that occur in the DHT."""
  18
  19 class DHT:
  20
  21     implements(IDHT)
  22
  23     def __init__(self):
  24         self.config = None
  25         self.cache_dir = ''
  26         self.bootstrap = []
  27         self.bootstrap_node = False
  28         self.joining = None
  29         self.joined = False
  30         self.outstandingJoins = 0
  31         self.foundAddrs = []
  32         self.storing = {}
  33         self.retrieving = {}
  34         self.retrieved = {}
  35
  36     def loadConfig(self, config, section):
  37         """See L{apt_dht.interfaces.IDHT}."""
  38         self.config_parser = config
  39         self.section = section
  40         self.config = {}
  41         self.cache_dir = os.path.join(self.config_parser.get(section, 'cache_dir'), khashmir_dir)
  42         if not os.path.exists(self.cache_dir):
  43             os.makedirs(self.cache_dir)
  44         self.bootstrap = self.config_parser.getstringlist(section, 'BOOTSTRAP')
  45         self.bootstrap_node = self.config_parser.getboolean(section, 'BOOTSTRAP_NODE')
  46         for k in self.config_parser.options(section):
  47             if k in ['K', 'HASH_LENGTH', 'CONCURRENT_REQS', 'STORE_REDUNDANCY',
  48                      'MAX_FAILURES', 'PORT']:
  49                 self.config[k] = self.config_parser.getint(section, k)
  50             elif k in ['CHECKPOINT_INTERVAL', 'MIN_PING_INTERVAL',
  51                        'BUCKET_STALENESS', 'KEINITIAL_DELAY', 'KE_DELAY', 'KE_AGE']:
  52                 self.config[k] = self.config_parser.gettime(section, k)
  53             elif k in ['SPEW']:
  54                 self.config[k] = self.config_parser.getboolean(section, k)
  55             else:
  56                 self.config[k] = self.config_parser.get(section, k)
  57
  58     def join(self):
  59         """See L{apt_dht.interfaces.IDHT}."""
  60         if self.config is None:
  61             raise DHTError, "configuration not loaded"
  62         if self.joining:
  63             raise DHTError, "a join is already in progress"
  64
  65         self.khashmir = Khashmir(self.config, self.cache_dir)
  66
  67         self.joining = defer.Deferred()
  68         for node in self.bootstrap:
  69             host, port = node.rsplit(':', 1)
  70             port = int(port)
  71             if isIPAddress(host):
  72                 self._join_gotIP(host, port)
  73             else:
  74                 reactor.resolve(host).addCallback(self._join_gotIP, port)
  75
  76         return self.joining
  77
  78     def _join_gotIP(self, ip, port):
  79         """Called after an IP address has been found for a single bootstrap node."""
  80         self.outstandingJoins += 1
  81         self.khashmir.addContact(ip, port, self._join_single, self._join_error)
  82
  83     def _join_single(self, addr):
  84         """Called when a single bootstrap node has been added."""
  85         self.outstandingJoins -= 1
  86         if addr:
  87             self.foundAddrs.append(addr)
  88         if addr or self.outstandingJoins <= 0:
  89             self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
  90         log.msg('Got back from bootstrap node: %r' % (addr,))
  91
  92     def _join_error(self, failure = None):
  93         """Called when a single bootstrap node has failed."""
  94         self.outstandingJoins -= 1
  95         log.msg("bootstrap node could not be reached")
  96         if self.outstandingJoins <= 0:
  97             self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
  98
  99     def _join_complete(self, result):
 100         """Called when the tables have been initialized with nodes."""
 101         if not self.joined and len(result) > 0:
 102             self.joined = True
 103         if self.joining and self.outstandingJoins <= 0:
 104             df = self.joining
 105             self.joining = None
 106             if self.joined or self.bootstrap_node:
 107                 self.joined = True
 108                 df.callback(self.foundAddrs)
 109             else:
 110                 df.errback(DHTError('could not find any nodes to bootstrap to'))
 111
 112     def getAddrs(self):
 113         return self.foundAddrs
 114
 115     def leave(self):
 116         """See L{apt_dht.interfaces.IDHT}."""
 117         if self.config is None:
 118             raise DHTError, "configuration not loaded"
 119
 120         if self.joined or self.joining:
 121             if self.joining:
 122                 self.joining.errback(DHTError('still joining when leave was called'))
 123                 self.joining = None
 124             self.joined = False
 125             self.khashmir.shutdown()
 126
 127     def getValue(self, key):
 128         """See L{apt_dht.interfaces.IDHT}."""
 129         if self.config is None:
 130             raise DHTError, "configuration not loaded"
 131         if not self.joined:
 132             raise DHTError, "have not joined a network yet"
 133
 134         d = defer.Deferred()
 135         if key not in self.retrieving:
 136             self.khashmir.valueForKey(key, self._getValue)
 137         self.retrieving.setdefault(key, []).append(d)
 138         return d
 139
 140     def _getValue(self, key, result):
 141         if result:
 142             self.retrieved.setdefault(key, []).extend(result)
 143         else:
 144             final_result = []
 145             if key in self.retrieved:
 146                 final_result = self.retrieved[key]
 147                 del self.retrieved[key]
 148             for i in range(len(self.retrieving[key])):
 149                 d = self.retrieving[key].pop(0)
 150                 d.callback(final_result)
 151             del self.retrieving[key]
 152
 153     def storeValue(self, key, value):
 154         """See L{apt_dht.interfaces.IDHT}."""
 155         if self.config is None:
 156             raise DHTError, "configuration not loaded"
 157         if not self.joined:
 158             raise DHTError, "have not joined a network yet"
 159
 160         if key in self.storing and value in self.storing[key]:
 161             raise DHTError, "already storing that key with the same value"
 162
 163         d = defer.Deferred()
 164         self.khashmir.storeValueForKey(key, value, self._storeValue)
 165         self.storing.setdefault(key, {})[value] = d
 166         return d
 167
 168     def _storeValue(self, key, value, result):
 169         if key in self.storing and value in self.storing[key]:
 170             if len(result) > 0:
 171                 self.storing[key][value].callback(result)
 172             else:
 173                 self.storing[key][value].errback(DHTError('could not store value %s in key %s' % (value, key)))
 174             del self.storing[key][value]
 175             if len(self.storing[key].keys()) == 0:
 176                 del self.storing[key]
 177
 178 class TestSimpleDHT(unittest.TestCase):
 179     """Unit tests for the DHT."""
 180
 181     timeout = 2
 182     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 183                     'CHECKPOINT_INTERVAL': 900, 'CONCURRENT_REQS': 4,
 184                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 185                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 186                     'KEINITIAL_DELAY': 15, 'KE_DELAY': 1200,
 187                     'KE_AGE': 3600, 'SPEW': False, }
 188
 189     def setUp(self):
 190         self.a = DHT()
 191         self.b = DHT()
 192         self.a.config = self.DHT_DEFAULTS.copy()
 193         self.a.config['PORT'] = 4044
 194         self.a.bootstrap = ["127.0.0.1:4044"]
 195         self.a.bootstrap_node = True
 196         self.a.cache_dir = '/tmp'
 197         self.b.config = self.DHT_DEFAULTS.copy()
 198         self.b.config['PORT'] = 4045
 199         self.b.bootstrap = ["127.0.0.1:4044"]
 200         self.b.cache_dir = '/tmp'
 201
 202     def test_bootstrap_join(self):
 203         d = self.a.join()
 204         return d
 205
 206     def node_join(self, result):
 207         d = self.b.join()
 208         return d
 209
 210     def test_join(self):
 211         self.lastDefer = defer.Deferred()
 212         d = self.a.join()
 213         d.addCallback(self.node_join)
 214         d.addCallback(self.lastDefer.callback)
 215         return self.lastDefer
 216
 217     def value_stored(self, result, value):
 218         self.stored -= 1
 219         if self.stored == 0:
 220             self.get_values()
 221
 222     def store_values(self, result):
 223         self.stored = 3
 224         d = self.a.storeValue(sha.new('4045').digest(), str(4045*3))
 225         d.addCallback(self.value_stored, 4045)
 226         d = self.a.storeValue(sha.new('4044').digest(), str(4044*2))
 227         d.addCallback(self.value_stored, 4044)
 228         d = self.b.storeValue(sha.new('4045').digest(), str(4045*2))
 229         d.addCallback(self.value_stored, 4045)
 230
 231     def check_values(self, result, values):
 232         self.checked -= 1
 233         self.failUnless(len(result) == len(values))
 234         for v in result:
 235             self.failUnless(v in values)
 236         if self.checked == 0:
 237             self.lastDefer.callback(1)
 238
 239     def get_values(self):
 240         self.checked = 4
 241         d = self.a.getValue(sha.new('4044').digest())
 242         d.addCallback(self.check_values, [str(4044*2)])
 243         d = self.b.getValue(sha.new('4044').digest())
 244         d.addCallback(self.check_values, [str(4044*2)])
 245         d = self.a.getValue(sha.new('4045').digest())
 246         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 247         d = self.b.getValue(sha.new('4045').digest())
 248         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 249
 250     def test_store(self):
 251         from twisted.internet.base import DelayedCall
 252         DelayedCall.debug = True
 253         self.lastDefer = defer.Deferred()
 254         d = self.a.join()
 255         d.addCallback(self.node_join)
 256         d.addCallback(self.store_values)
 257         return self.lastDefer
 258
 259     def tearDown(self):
 260         self.a.leave()
 261         try:
 262             os.unlink(self.a.khashmir.store.db)
 263         except:
 264             pass
 265         self.b.leave()
 266         try:
 267             os.unlink(self.b.khashmir.store.db)
 268         except:
 269             pass
 270
 271 class TestMultiDHT(unittest.TestCase):
 272
 273     timeout = 60
 274     num = 20
 275     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 276                     'CHECKPOINT_INTERVAL': 900, 'CONCURRENT_REQS': 4,
 277                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 278                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 279                     'KEINITIAL_DELAY': 15, 'KE_DELAY': 1200,
 280                     'KE_AGE': 3600, 'SPEW': False, }
 281
 282     def setUp(self):
 283         self.l = []
 284         self.startport = 4081
 285         for i in range(self.num):
 286             self.l.append(DHT())
 287             self.l[i].config = self.DHT_DEFAULTS.copy()
 288             self.l[i].config['PORT'] = self.startport + i
 289             self.l[i].bootstrap = ["127.0.0.1:" + str(self.startport)]
 290             self.l[i].cache_dir = '/tmp'
 291         self.l[0].bootstrap_node = True
 292
 293     def node_join(self, result, next_node):
 294         d = self.l[next_node].join()
 295         if next_node + 1 < len(self.l):
 296             d.addCallback(self.node_join, next_node + 1)
 297         else:
 298             d.addCallback(self.lastDefer.callback)
 299
 300     def test_join(self):
 301         self.timeout = 2
 302         self.lastDefer = defer.Deferred()
 303         d = self.l[0].join()
 304         d.addCallback(self.node_join, 1)
 305         return self.lastDefer
 306
 307     def store_values(self, result, i = 0, j = 0):
 308         if j > i:
 309             j -= i+1
 310             i += 1
 311         if i == len(self.l):
 312             self.get_values()
 313         else:
 314             d = self.l[j].storeValue(sha.new(str(self.startport+i)).digest(), str((self.startport+i)*(j+1)))
 315             d.addCallback(self.store_values, i, j+1)
 316
 317     def get_values(self, result = None, check = None, i = 0, j = 0):
 318         if result is not None:
 319             self.failUnless(len(result) == len(check))
 320             for v in result:
 321                 self.failUnless(v in check)
 322         if j >= len(self.l):
 323             j -= len(self.l)
 324             i += 1
 325         if i == len(self.l):
 326             self.lastDefer.callback(1)
 327         else:
 328             d = self.l[i].getValue(sha.new(str(self.startport+j)).digest())
 329             check = []
 330             for k in range(self.startport+j, (self.startport+j)*(j+1)+1, self.startport+j):
 331                 check.append(str(k))
 332             d.addCallback(self.get_values, check, i, j + random.randrange(1, min(len(self.l), 10)))
 333
 334     def store_join(self, result, next_node):
 335         d = self.l[next_node].join()
 336         if next_node + 1 < len(self.l):
 337             d.addCallback(self.store_join, next_node + 1)
 338         else:
 339             d.addCallback(self.store_values)
 340
 341     def test_store(self):
 342         from twisted.internet.base import DelayedCall
 343         DelayedCall.debug = True
 344         self.lastDefer = defer.Deferred()
 345         d = self.l[0].join()
 346         d.addCallback(self.store_join, 1)
 347         return self.lastDefer
 348
 349     def tearDown(self):
 350         for i in self.l:
 351             try:
 352                 i.leave()
 353                 os.unlink(i.khashmir.store.db)
 354             except:
 355                 pass