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                      '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 getValue(self, key):
 129         """See L{apt_dht.interfaces.IDHT}."""
 130         if self.config is None:
 131             raise DHTError, "configuration not loaded"
 132         if not self.joined:
 133             raise DHTError, "have not joined a network yet"
 134
 135         d = defer.Deferred()
 136         if key not in self.retrieving:
 137             self.khashmir.valueForKey(key, self._getValue)
 138         self.retrieving.setdefault(key, []).append(d)
 139         return d
 140
 141     def _getValue(self, key, result):
 142         if result:
 143             self.retrieved.setdefault(key, []).extend([bdecode(r) for r in result])
 144         else:
 145             final_result = []
 146             if key in self.retrieved:
 147                 final_result = self.retrieved[key]
 148                 del self.retrieved[key]
 149             for i in range(len(self.retrieving[key])):
 150                 d = self.retrieving[key].pop(0)
 151                 d.callback(final_result)
 152             del self.retrieving[key]
 153
 154     def storeValue(self, key, value):
 155         """See L{apt_dht.interfaces.IDHT}."""
 156         if self.config is None:
 157             raise DHTError, "configuration not loaded"
 158         if not self.joined:
 159             raise DHTError, "have not joined a network yet"
 160
 161         bvalue = bencode(value)
 162
 163         if key in self.storing and bvalue in self.storing[key]:
 164             raise DHTError, "already storing that key with the same value"
 165
 166         d = defer.Deferred()
 167         self.khashmir.storeValueForKey(key, bvalue, self._storeValue)
 168         self.storing.setdefault(key, {})[bvalue] = d
 169         return d
 170
 171     def _storeValue(self, key, bvalue, result):
 172         if key in self.storing and bvalue in self.storing[key]:
 173             if len(result) > 0:
 174                 self.storing[key][bvalue].callback(result)
 175             else:
 176                 self.storing[key][bvalue].errback(DHTError('could not store value %s in key %s' % (bvalue, key)))
 177             del self.storing[key][bvalue]
 178             if len(self.storing[key].keys()) == 0:
 179                 del self.storing[key]
 180
 181 class TestSimpleDHT(unittest.TestCase):
 182     """Unit tests for the DHT."""
 183
 184     timeout = 2
 185     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 186                     'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
 187                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 188                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 189                     'KEY_EXPIRE': 3600, 'SPEW': False, }
 190
 191     def setUp(self):
 192         self.a = DHT()
 193         self.b = DHT()
 194         self.a.config = self.DHT_DEFAULTS.copy()
 195         self.a.config['PORT'] = 4044
 196         self.a.bootstrap = ["127.0.0.1:4044"]
 197         self.a.bootstrap_node = True
 198         self.a.cache_dir = '/tmp'
 199         self.b.config = self.DHT_DEFAULTS.copy()
 200         self.b.config['PORT'] = 4045
 201         self.b.bootstrap = ["127.0.0.1:4044"]
 202         self.b.cache_dir = '/tmp'
 203
 204     def test_bootstrap_join(self):
 205         d = self.a.join()
 206         return d
 207
 208     def node_join(self, result):
 209         d = self.b.join()
 210         return d
 211
 212     def test_join(self):
 213         self.lastDefer = defer.Deferred()
 214         d = self.a.join()
 215         d.addCallback(self.node_join)
 216         d.addCallback(self.lastDefer.callback)
 217         return self.lastDefer
 218
 219     def value_stored(self, result, value):
 220         self.stored -= 1
 221         if self.stored == 0:
 222             self.get_values()
 223
 224     def store_values(self, result):
 225         self.stored = 3
 226         d = self.a.storeValue(sha.new('4045').digest(), str(4045*3))
 227         d.addCallback(self.value_stored, 4045)
 228         d = self.a.storeValue(sha.new('4044').digest(), str(4044*2))
 229         d.addCallback(self.value_stored, 4044)
 230         d = self.b.storeValue(sha.new('4045').digest(), str(4045*2))
 231         d.addCallback(self.value_stored, 4045)
 232
 233     def check_values(self, result, values):
 234         self.checked -= 1
 235         self.failUnless(len(result) == len(values))
 236         for v in result:
 237             self.failUnless(v in values)
 238         if self.checked == 0:
 239             self.lastDefer.callback(1)
 240
 241     def get_values(self):
 242         self.checked = 4
 243         d = self.a.getValue(sha.new('4044').digest())
 244         d.addCallback(self.check_values, [str(4044*2)])
 245         d = self.b.getValue(sha.new('4044').digest())
 246         d.addCallback(self.check_values, [str(4044*2)])
 247         d = self.a.getValue(sha.new('4045').digest())
 248         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 249         d = self.b.getValue(sha.new('4045').digest())
 250         d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
 251
 252     def test_store(self):
 253         from twisted.internet.base import DelayedCall
 254         DelayedCall.debug = True
 255         self.lastDefer = defer.Deferred()
 256         d = self.a.join()
 257         d.addCallback(self.node_join)
 258         d.addCallback(self.store_values)
 259         return self.lastDefer
 260
 261     def tearDown(self):
 262         self.a.leave()
 263         try:
 264             os.unlink(self.a.khashmir.store.db)
 265         except:
 266             pass
 267         self.b.leave()
 268         try:
 269             os.unlink(self.b.khashmir.store.db)
 270         except:
 271             pass
 272
 273 class TestMultiDHT(unittest.TestCase):
 274
 275     timeout = 60
 276     num = 20
 277     DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
 278                     'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
 279                     'STORE_REDUNDANCY': 3, 'MAX_FAILURES': 3,
 280                     'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
 281                     'KEY_EXPIRE': 3600, 'SPEW': False, }
 282
 283     def setUp(self):
 284         self.l = []
 285         self.startport = 4081
 286         for i in range(self.num):
 287             self.l.append(DHT())
 288             self.l[i].config = self.DHT_DEFAULTS.copy()
 289             self.l[i].config['PORT'] = self.startport + i
 290             self.l[i].bootstrap = ["127.0.0.1:" + str(self.startport)]
 291             self.l[i].cache_dir = '/tmp'
 292         self.l[0].bootstrap_node = True
 293
 294     def node_join(self, result, next_node):
 295         d = self.l[next_node].join()
 296         if next_node + 1 < len(self.l):
 297             d.addCallback(self.node_join, next_node + 1)
 298         else:
 299             d.addCallback(self.lastDefer.callback)
 300
 301     def test_join(self):
 302         self.timeout = 2
 303         self.lastDefer = defer.Deferred()
 304         d = self.l[0].join()
 305         d.addCallback(self.node_join, 1)
 306         return self.lastDefer
 307
 308     def store_values(self, result, i = 0, j = 0):
 309         if j > i:
 310             j -= i+1
 311             i += 1
 312         if i == len(self.l):
 313             self.get_values()
 314         else:
 315             d = self.l[j].storeValue(sha.new(str(self.startport+i)).digest(), str((self.startport+i)*(j+1)))
 316             d.addCallback(self.store_values, i, j+1)
 317
 318     def get_values(self, result = None, check = None, i = 0, j = 0):
 319         if result is not None:
 320             self.failUnless(len(result) == len(check))
 321             for v in result:
 322                 self.failUnless(v in check)
 323         if j >= len(self.l):
 324             j -= len(self.l)
 325             i += 1
 326         if i == len(self.l):
 327             self.lastDefer.callback(1)
 328         else:
 329             d = self.l[i].getValue(sha.new(str(self.startport+j)).digest())
 330             check = []
 331             for k in range(self.startport+j, (self.startport+j)*(j+1)+1, self.startport+j):
 332                 check.append(str(k))
 333             d.addCallback(self.get_values, check, i, j + random.randrange(1, min(len(self.l), 10)))
 334
 335     def store_join(self, result, next_node):
 336         d = self.l[next_node].join()
 337         if next_node + 1 < len(self.l):
 338             d.addCallback(self.store_join, next_node + 1)
 339         else:
 340             d.addCallback(self.store_values)
 341
 342     def test_store(self):
 343         from twisted.internet.base import DelayedCall
 344         DelayedCall.debug = True
 345         self.lastDefer = defer.Deferred()
 346         d = self.l[0].join()
 347         d.addCallback(self.store_join, 1)
 348         return self.lastDefer
 349
 350     def tearDown(self):
 351         for i in self.l:
 352             try:
 353                 i.leave()
 354                 os.unlink(i.khashmir.store.db)
 355             except:
 356                 pass