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