apt_dht_Khashmir/DHT.py

   1
   2 import os, sha, random
   3
   4 from twisted.internet import defer, reactor
   5 from twisted.internet.abstract import isIPAddress
   6 from twisted.trial import unittest
   7 from zope.interface import implements
   8
   9 from apt_dht.interfaces import IDHT
  10 from khashmir import Khashmir
  11
  12 class DHTError(Exception):
  13     """Represents errors that occur in the DHT."""
  14
  15 class DHT:
  16
  17     implements(IDHT)
  18
  19     def __init__(self):
  20         self.config = None
  21         self.cache_dir = ''
  22         self.bootstrap = []
  23         self.bootstrap_node = False
  24         self.joining = None
  25         self.joined = False
  26         self.storing = {}
  27         self.retrieving = {}
  28         self.retrieved = {}
  29
  30     def loadConfig(self, config, section):
  31         """See L{apt_dht.interfaces.IDHT}."""
  32         self.config_parser = config
  33         self.section = section
  34         self.config = {}
  35         self.cache_dir = self.config_parser.get(section, 'cache_dir')
  36         self.bootstrap = self.config_parser.getstringlist(section, 'BOOTSTRAP')
  37         self.bootstrap_node = self.config_parser.getboolean(section, 'BOOTSTRAP_NODE')
  38         for k in self.config_parser.options(section):
  39             if k in ['K', 'HASH_LENGTH', 'CONCURRENT_REQS', 'STORE_REDUNDANCY',
  40                      'MAX_FAILURES', 'PORT']:
  41                 self.config[k] = self.config_parser.getint(section, k)
  42             elif k in ['CHECKPOINT_INTERVAL', 'MIN_PING_INTERVAL',
  43                        'BUCKET_STALENESS', 'KEINITIAL_DELAY', 'KE_DELAY', 'KE_AGE']:
  44                 self.config[k] = self.config_parser.gettime(section, k)
  45             else:
  46                 self.config[k] = self.config_parser.get(section, k)
  47
  48     def join(self):
  49         """See L{apt_dht.interfaces.IDHT}."""
  50         if self.config is None:
  51             raise DHTError, "configuration not loaded"
  52         if self.joining:
  53             raise DHTError, "a join is already in progress"
  54
  55         self.khashmir = Khashmir(self.config, self.cache_dir)
  56
  57         self.joining = defer.Deferred()
  58         for node in self.bootstrap:
  59             host, port = node.rsplit(':', 1)
  60             port = int(port)
  61             if isIPAddress(host):
  62                 self._join_gotIP(host, port)
  63             else:
  64                 reactor.resolve(host).addCallback(self._join_gotIP, port)
  65
  66         return self.joining
  67
  68     def _join_gotIP(self, ip, port):
  69         """Called after an IP address has been found for a single bootstrap node."""
  70         self.khashmir.addContact(ip, port, self._join_single)
  71
  72     def _join_single(self):
  73         """Called when a single bootstrap node has been added."""
  74         self.khashmir.findCloseNodes(self._join_complete)
  75
  76     def _join_complete(self, result):
  77         """Called when the tables have been initialized with nodes."""
  78         if not self.joined:
  79             self.joined = True
  80             if len(result) > 0 or self.bootstrap_node:
  81                 df = self.joining
  82                 self.joining = None
  83                 df.callback(result)
  84             else:
  85                 df = self.joining
  86                 self.joining = None
  87                 df.errback(DHTError('could not find any nodes to bootstrap to'))
  88
  89     def leave(self):
  90         """See L{apt_dht.interfaces.IDHT}."""
  91         if self.config is None:
  92             raise DHTError, "configuration not loaded"
  93
  94         if self.joined or self.joining:
  95             if self.joining:
  96                 self.joining.errback(DHTError('still joining when leave was called'))
  97                 self.joining = None
  98             self.joined = False
  99             self.khashmir.shutdown()
 100
 101     def normalizeKey(self, key):
 102         """Normalize a key's length suitable for insertion in the DHT."""
 103         key_bytes = (self.config['HASH_LENGTH'] - 1) // 8 + 1
 104         if len(key) < key_bytes:
 105             key = key + '\000'*(key_bytes - len(key))
 106         elif len(key) > key_bytes:
 107             key = key[:key_bytes]
 108         return key
 109
 110     def getValue(self, key):
 111         """See L{apt_dht.interfaces.IDHT}."""
 112         if self.config is None:
 113             raise DHTError, "configuration not loaded"
 114         if not self.joined:
 115             raise DHTError, "have not joined a network yet"
 116
 117         d = defer.Deferred()
 118         key = self.normalizeKey(key)
 119         if key not in self.retrieving:
 120             self.khashmir.valueForKey(key, self._getValue)
 121         self.retrieving.setdefault(key, []).append(d)
 122         return d
 123
 124     def _getValue(self, key, result):
 125         if result:
 126             self.retrieved.setdefault(key, []).extend(result)
 127         else:
 128             final_result = []
 129             if key in self.retrieved:
 130                 final_result = self.retrieved[key]
 131                 del self.retrieved[key]
 132             for i in range(len(self.retrieving[key])):
 133                 d = self.retrieving[key].pop(0)
 134                 d.callback(final_result)
 135             del self.retrieving[key]
 136
 137     def storeValue(self, key, value):
 138         """See L{apt_dht.interfaces.IDHT}."""
 139         if self.config is None:
 140             raise DHTError, "configuration not loaded"
 141         if not self.joined:
 142             raise DHTError, "have not joined a network yet"
 143
 144         key = self.normalizeKey(key)
 145         if key in self.storing and value in self.storing[key]:
 146             raise DHTError, "already storing that key with the same value"
 147
 148         d = defer.Deferred()
 149         self.khashmir.storeValueForKey(key, value, self._storeValue)
 150         self.storing.setdefault(key, {})[value] = d
 151         return d
 152
 153     def _storeValue(self, key, value, result):
 154         if key in self.storing and value in self.storing[key]:
 155             if len(result) > 0:
 156                 self.storing[key][value].callback(result)
 157             else:
 158                 self.storing[key][value].errback(DHTError('could not store value %s in key %s' % (value, key)))
 159             del self.storing[key][value]
 160             if len(self.storing[key].keys()) == 0:
 161                 del self.storing[key]
 162
 163 class TestSimpleDHT(unittest.TestCase):
 164     """Unit tests for the DHT."""
 165
 166     timeout = 2
 167     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 168                     'CHECKPOINT_INTERVAL': 900, 'CONCURRENT_REQS': 4,
 169                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 170                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 171                     'KEINITIAL_DELAY': 15, 'KE_DELAY': 1200,
 172                     'KE_AGE': 3600, }
 173
 174     def setUp(self):
 175         self.a = DHT()
 176         self.b = DHT()
 177         self.a.config = self.DHT_DEFAULTS.copy()
 178         self.a.config['PORT'] = 4044
 179         self.a.bootstrap = ["127.0.0.1:4044"]
 180         self.a.bootstrap_node = True
 181         self.a.cache_dir = '/tmp'
 182         self.b.config = self.DHT_DEFAULTS.copy()
 183         self.b.config['PORT'] = 4045
 184         self.b.bootstrap = ["127.0.0.1:4044"]
 185         self.b.cache_dir = '/tmp'
 186
 187     def test_normalizeKey(self):
 188         self.failUnless(self.a.normalizeKey('12345678901234567890') == '12345678901234567890')
 189         self.failUnless(self.a.normalizeKey('12345678901234567') == '12345678901234567\000\000\000')
 190         self.failUnless(self.a.normalizeKey('1234567890123456789012345') == '12345678901234567890')
 191         self.failUnless(self.a.normalizeKey('1234567890123456789') == '1234567890123456789\000')
 192         self.failUnless(self.a.normalizeKey('123456789012345678901') == '12345678901234567890')
 193
 194     def test_bootstrap_join(self):
 195         d = self.a.join()
 196         return d
 197
 198     def node_join(self, result):
 199         d = self.b.join()
 200         return d
 201
 202     def test_join(self):
 203         self.lastDefer = defer.Deferred()
 204         d = self.a.join()
 205         d.addCallback(self.node_join)
 206         d.addCallback(self.lastDefer.callback)
 207         return self.lastDefer
 208
 209     def value_stored(self, result, value):
 210         self.stored -= 1
 211         if self.stored == 0:
 212             self.get_values()
 213
 214     def store_values(self, result):
 215         self.stored = 3
 216         d = self.a.storeValue(sha.new('4045').digest(), str(4045*3))
 217         d.addCallback(self.value_stored, 4045)
 218         d = self.a.storeValue(sha.new('4044').digest(), str(4044*2))
 219         d.addCallback(self.value_stored, 4044)
 220         d = self.b.storeValue(sha.new('4045').digest(), str(4045*2))
 221         d.addCallback(self.value_stored, 4045)
 222
 223     def check_values(self, result, values):
 224         self.checked -= 1
 225         self.failUnless(len(result) == len(values))
 226         for v in result:
 227             self.failUnless(v in values)
 228         if self.checked == 0:
 229             self.lastDefer.callback(1)
 230
 231     def get_values(self):
 232         self.checked = 4
 233         d = self.a.getValue(sha.new('4044').digest())
 234         d.addCallback(self.check_values, [str(4044*2)])
 235         d = self.b.getValue(sha.new('4044').digest())
 236         d.addCallback(self.check_values, [str(4044*2)])
 237         d = self.a.getValue(sha.new('4045').digest())
 238         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 239         d = self.b.getValue(sha.new('4045').digest())
 240         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 241
 242     def test_store(self):
 243         from twisted.internet.base import DelayedCall
 244         DelayedCall.debug = True
 245         self.lastDefer = defer.Deferred()
 246         d = self.a.join()
 247         d.addCallback(self.node_join)
 248         d.addCallback(self.store_values)
 249         return self.lastDefer
 250
 251     def tearDown(self):
 252         self.a.leave()
 253         try:
 254             os.unlink(self.a.khashmir.store.db)
 255         except:
 256             pass
 257         self.b.leave()
 258         try:
 259             os.unlink(self.b.khashmir.store.db)
 260         except:
 261             pass
 262
 263 class TestMultiDHT(unittest.TestCase):
 264
 265     timeout = 60
 266     num = 20
 267     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 268                     'CHECKPOINT_INTERVAL': 900, 'CONCURRENT_REQS': 4,
 269                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 270                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 271                     'KEINITIAL_DELAY': 15, 'KE_DELAY': 1200,
 272                     'KE_AGE': 3600, }
 273
 274     def setUp(self):
 275         self.l = []
 276         self.startport = 4081
 277         for i in range(self.num):
 278             self.l.append(DHT())
 279             self.l[i].config = self.DHT_DEFAULTS.copy()
 280             self.l[i].config['PORT'] = self.startport + i
 281             self.l[i].bootstrap = ["127.0.0.1:" + str(self.startport)]
 282             self.l[i].cache_dir = '/tmp'
 283         self.l[0].bootstrap_node = True
 284
 285     def node_join(self, result, next_node):
 286         d = self.l[next_node].join()
 287         if next_node + 1 < len(self.l):
 288             d.addCallback(self.node_join, next_node + 1)
 289         else:
 290             d.addCallback(self.lastDefer.callback)
 291
 292     def test_join(self):
 293         self.timeout = 2
 294         self.lastDefer = defer.Deferred()
 295         d = self.l[0].join()
 296         d.addCallback(self.node_join, 1)
 297         return self.lastDefer
 298
 299     def value_stored(self, result, value):
 300         self.stored -= 1
 301         if self.stored == 0:
 302             self.get_values()
 303
 304     def store_values(self, result):
 305         self.stored = 0
 306         for i in range(len(self.l)):
 307             for j in range(0, i+1):
 308                 self.stored += 1
 309                 d = self.l[j].storeValue(sha.new(str(self.startport+i)).digest(), str((self.startport+i)*(j+1)))
 310                 d.addCallback(self.value_stored, self.startport+i)
 311
 312     def check_values(self, result, values):
 313         self.checked -= 1
 314         self.failUnless(len(result) == len(values))
 315         for v in result:
 316             self.failUnless(v in values)
 317         if self.checked == 0:
 318             self.lastDefer.callback(1)
 319
 320     def get_values(self):
 321         self.checked = 0
 322         for i in range(len(self.l)):
 323             for j in random.sample(xrange(len(self.l)), max(len(self.l), 4)):
 324                 self.checked += 1
 325                 d = self.l[i].getValue(sha.new(str(self.startport+j)).digest())
 326                 check = []
 327                 for k in range(self.startport+j, (self.startport+j)*(j+1)+1, self.startport+j):
 328                     check.append(str(k))
 329                 d.addCallback(self.check_values, check)
 330
 331     def store_join(self, result, next_node):
 332         d = self.l[next_node].join()
 333         if next_node + 1 < len(self.l):
 334             d.addCallback(self.store_join, next_node + 1)
 335         else:
 336             d.addCallback(self.store_values)
 337
 338     def test_store(self):
 339         from twisted.internet.base import DelayedCall
 340         DelayedCall.debug = True
 341         self.lastDefer = defer.Deferred()
 342         d = self.l[0].join()
 343         d.addCallback(self.store_join, 1)
 344         return self.lastDefer
 345
 346     def tearDown(self):
 347         for i in self.l:
 348             try:
 349                 i.leave()
 350                 os.unlink(i.khashmir.store.db)
 351             except:
 352                 pass