]> git.mxchange.org Git - quix0rs-apt-p2p.git/blobdiff - apt_dht_Khashmir/DHT.py
Document the DHT's DHT module.
[quix0rs-apt-p2p.git] / apt_dht_Khashmir / DHT.py
index c4a0b340ec786d2537b4a331a2d0c117793c21bf..81c2696e1a3f0871b98fdea83409e9a5d310f45c 100644 (file)
 
-from twisted.internet import defer
+"""The main interface to the Khashmir DHT.
+
+@var khashmir_dir: the name of the directory to use for DHT files
+"""
+
+from datetime import datetime
+import os, sha, random
+
+from twisted.internet import defer, reactor
+from twisted.internet.abstract import isIPAddress
+from twisted.python import log
+from twisted.trial import unittest
 from zope.interface import implements
 
 from apt_dht.interfaces import IDHT
 from khashmir import Khashmir
+from bencode import bencode, bdecode
+
+khashmir_dir = 'apt-dht-Khashmir'
 
 class DHTError(Exception):
     """Represents errors that occur in the DHT."""
 
 class DHT:
+    """The main interface instance to the Khashmir DHT.
+    
+    @type config: C{dictionary}
+    @ivar config: the DHT configuration values
+    @type cache_dir: C{string}
+    @ivar cache_dir: the directory to use for storing files
+    @type bootstrap: C{list} of C{string}
+    @ivar bootstrap: the nodes to contact to bootstrap into the system
+    @type bootstrap_node: C{boolean}
+    @ivar bootstrap_node: whether this node is a bootstrap node
+    @type joining: L{twisted.internet.defer.Deferred}
+    @ivar joining: if a join is underway, the deferred that will signal it's end
+    @type joined: C{boolean}
+    @ivar joined: whether the DHT network has been successfully joined
+    @type outstandingJoins: C{int}
+    @ivar outstandingJoins: the number of bootstrap nodes that have yet to respond
+    @type foundAddrs: C{list} of (C{string}, C{int})
+    @ivar foundAddrs: the IP address an port that were returned by bootstrap nodes
+    @type storing: C{dictionary}
+    @ivar storing: keys are keys for which store requests are active, values
+        are dictionaries with keys the values being stored and values the
+        deferred to call when complete
+    @type retrieving: C{dictionary}
+    @ivar retrieving: keys are the keys for which getValue requests are active,
+        values are lists of the deferreds waiting for the requests
+    @type retrieved: C{dictionary}
+    @ivar retrieved: keys are the keys for which getValue requests are active,
+        values are list of the values returned so far
+    @type config_parser: L{apt_dht.apt_dht_conf.AptDHTConfigParser}
+    @ivar config_parser: the configuration info for the main program
+    @type section: C{string}
+    @ivar section: the section of the configuration info that applies to the DHT
+    @type khashmir: L{khashmir.Khashmir}
+    @ivar khashmir: the khashmir DHT instance to use
+    """
     
     implements(IDHT)
     
     def __init__(self):
+        """Initialize the DHT."""
         self.config = None
+        self.cache_dir = ''
+        self.bootstrap = []
+        self.bootstrap_node = False
+        self.joining = None
+        self.joined = False
+        self.outstandingJoins = 0
+        self.foundAddrs = []
+        self.storing = {}
+        self.retrieving = {}
+        self.retrieved = {}
     
     def loadConfig(self, config, section):
         """See L{apt_dht.interfaces.IDHT}."""
         self.config_parser = config
         self.section = section
-        self.config = []
+        self.config = {}
+        
+        # Get some initial values
+        self.cache_dir = os.path.join(self.config_parser.get(section, 'cache_dir'), khashmir_dir)
+        if not os.path.exists(self.cache_dir):
+            os.makedirs(self.cache_dir)
+        self.bootstrap = self.config_parser.getstringlist(section, 'BOOTSTRAP')
+        self.bootstrap_node = self.config_parser.getboolean(section, 'BOOTSTRAP_NODE')
         for k in self.config_parser.options(section):
+            # The numbers in the config file
             if k in ['K', 'HASH_LENGTH', 'CONCURRENT_REQS', 'STORE_REDUNDANCY', 
-                     'MAX_FAILURES', 'PORT']:
+                     'RETRIEVE_VALUES', 'MAX_FAILURES', 'PORT']:
                 self.config[k] = self.config_parser.getint(section, k)
+            # The times in the config file
             elif k in ['CHECKPOINT_INTERVAL', 'MIN_PING_INTERVAL', 
-                       'BUCKET_STALENESS', 'KEINITIAL_DELAY', 'KE_DELAY', 'KE_AGE']:
+                       'BUCKET_STALENESS', 'KEY_EXPIRE']:
                 self.config[k] = self.config_parser.gettime(section, k)
+            # The booleans in the config file
+            elif k in ['SPEW']:
+                self.config[k] = self.config_parser.getboolean(section, k)
+            # Everything else is a string
             else:
                 self.config[k] = self.config_parser.get(section, k)
-        if 'PORT' not in self.config:
-            self.config['PORT'] = self.config_parser.getint('DEFAULT', 'PORT')
     
     def join(self):
         """See L{apt_dht.interfaces.IDHT}."""
         if self.config is None:
             raise DHTError, "configuration not loaded"
+        if self.joining:
+            raise DHTError, "a join is already in progress"
 
-        self.khashmir = Khashmir(self.config, self.config_parser.get('DEFAULT', 'cache_dir'))
+        # Create the new khashmir instance
+        self.khashmir = Khashmir(self.config, self.cache_dir)
         
-        for node in self.config_parser.get(self.section, 'BOOTSTRAP'):
+        self.joining = defer.Deferred()
+        for node in self.bootstrap:
             host, port = node.rsplit(':', 1)
-            self.khashmir.addContact(host, port)
+            port = int(port)
             
-        self.khashmir.findCloseNodes()
+            # Translate host names into IP addresses
+            if isIPAddress(host):
+                self._join_gotIP(host, port)
+            else:
+                reactor.resolve(host).addCallback(self._join_gotIP, port)
+        
+        return self.joining
+
+    def _join_gotIP(self, ip, port):
+        """Join the DHT using a single bootstrap nodes IP address."""
+        self.outstandingJoins += 1
+        self.khashmir.addContact(ip, port, self._join_single, self._join_error)
+    
+    def _join_single(self, addr):
+        """Process the response from the bootstrap node.
+        
+        Finish the join by contacting close nodes.
+        """
+        self.outstandingJoins -= 1
+        if addr:
+            self.foundAddrs.append(addr)
+        if addr or self.outstandingJoins <= 0:
+            self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
+        log.msg('Got back from bootstrap node: %r' % (addr,))
+    
+    def _join_error(self, failure = None):
+        """Process an error in contacting the bootstrap node.
+        
+        If no bootstrap nodes remain, finish the process by contacting
+        close nodes.
+        """
+        self.outstandingJoins -= 1
+        log.msg("bootstrap node could not be reached")
+        if self.outstandingJoins <= 0:
+            self.khashmir.findCloseNodes(self._join_complete, self._join_complete)
+
+    def _join_complete(self, result):
+        """End the joining process and return the addresses found for this node."""
+        if not self.joined and len(result) > 0:
+            self.joined = True
+        if self.joining and self.outstandingJoins <= 0:
+            df = self.joining
+            self.joining = None
+            if self.joined or self.bootstrap_node:
+                self.joined = True
+                df.callback(self.foundAddrs)
+            else:
+                df.errback(DHTError('could not find any nodes to bootstrap to'))
+        
+    def getAddrs(self):
+        """Get the list of addresses returned by bootstrap nodes for this node."""
+        return self.foundAddrs
         
     def leave(self):
         """See L{apt_dht.interfaces.IDHT}."""
         if self.config is None:
             raise DHTError, "configuration not loaded"
-
-        self.khashmir.listenport.stopListening()
         
+        if self.joined or self.joining:
+            if self.joining:
+                self.joining.errback(DHTError('still joining when leave was called'))
+                self.joining = None
+            self.joined = False
+            self.khashmir.shutdown()
+        
+    def _normKey(self, key, bits=None, bytes=None):
+        """Normalize the length of keys used in the DHT."""
+        bits = self.config["HASH_LENGTH"]
+        if bits is not None:
+            bytes = (bits - 1) // 8 + 1
+        else:
+            if bytes is None:
+                raise DHTError, "you must specify one of bits or bytes for normalization"
+            
+        # Extend short keys with null bytes
+        if len(key) < bytes:
+            key = key + '\000'*(bytes - len(key))
+        # Truncate long keys
+        elif len(key) > bytes:
+            key = key[:bytes]
+        return key
+
     def getValue(self, key):
         """See L{apt_dht.interfaces.IDHT}."""
         if self.config is None:
             raise DHTError, "configuration not loaded"
+        if not self.joined:
+            raise DHTError, "have not joined a network yet"
+        
+        key = self._normKey(key)
 
         d = defer.Deferred()
-        self.khashmir.valueForKey(key, d.callback)
+        if key not in self.retrieving:
+            self.khashmir.valueForKey(key, self._getValue)
+        self.retrieving.setdefault(key, []).append(d)
         return d
         
+    def _getValue(self, key, result):
+        """Process a returned list of values from the DHT."""
+        # Save the list of values to return when it is complete
+        if result:
+            self.retrieved.setdefault(key, []).extend([bdecode(r) for r in result])
+        else:
+            # Empty list, the get is complete, return the result
+            final_result = []
+            if key in self.retrieved:
+                final_result = self.retrieved[key]
+                del self.retrieved[key]
+            for i in range(len(self.retrieving[key])):
+                d = self.retrieving[key].pop(0)
+                d.callback(final_result)
+            del self.retrieving[key]
+
     def storeValue(self, key, value):
         """See L{apt_dht.interfaces.IDHT}."""
         if self.config is None:
             raise DHTError, "configuration not loaded"
+        if not self.joined:
+            raise DHTError, "have not joined a network yet"
+
+        key = self._normKey(key)
+        bvalue = bencode(value)
+
+        if key in self.storing and bvalue in self.storing[key]:
+            raise DHTError, "already storing that key with the same value"
+
+        d = defer.Deferred()
+        self.khashmir.storeValueForKey(key, bvalue, self._storeValue)
+        self.storing.setdefault(key, {})[bvalue] = d
+        return d
+    
+    def _storeValue(self, key, bvalue, result):
+        """Process the response from the DHT."""
+        if key in self.storing and bvalue in self.storing[key]:
+            # Check if the store succeeded
+            if len(result) > 0:
+                self.storing[key][bvalue].callback(result)
+            else:
+                self.storing[key][bvalue].errback(DHTError('could not store value %s in key %s' % (bvalue, key)))
+            del self.storing[key][bvalue]
+            if len(self.storing[key].keys()) == 0:
+                del self.storing[key]
+
+class TestSimpleDHT(unittest.TestCase):
+    """Simple 2-node unit tests for the DHT."""
+    
+    timeout = 2
+    DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
+                    'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
+                    'STORE_REDUNDANCY': 3, 'RETRIEVE_VALUES': -10000,
+                    'MAX_FAILURES': 3,
+                    'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
+                    'KEY_EXPIRE': 3600, 'SPEW': False, }
+
+    def setUp(self):
+        self.a = DHT()
+        self.b = DHT()
+        self.a.config = self.DHT_DEFAULTS.copy()
+        self.a.config['PORT'] = 4044
+        self.a.bootstrap = ["127.0.0.1:4044"]
+        self.a.bootstrap_node = True
+        self.a.cache_dir = '/tmp'
+        self.b.config = self.DHT_DEFAULTS.copy()
+        self.b.config['PORT'] = 4045
+        self.b.bootstrap = ["127.0.0.1:4044"]
+        self.b.cache_dir = '/tmp'
+        
+    def test_bootstrap_join(self):
+        d = self.a.join()
+        return d
+        
+    def node_join(self, result):
+        d = self.b.join()
+        return d
+    
+    def test_join(self):
+        self.lastDefer = defer.Deferred()
+        d = self.a.join()
+        d.addCallback(self.node_join)
+        d.addCallback(self.lastDefer.callback)
+        return self.lastDefer
+
+    def test_normKey(self):
+        h = self.a._normKey('12345678901234567890')
+        self.failUnless(h == '12345678901234567890')
+        h = self.a._normKey('12345678901234567')
+        self.failUnless(h == '12345678901234567\000\000\000')
+        h = self.a._normKey('1234567890123456789012345')
+        self.failUnless(h == '12345678901234567890')
+        h = self.a._normKey('1234567890123456789')
+        self.failUnless(h == '1234567890123456789\000')
+        h = self.a._normKey('123456789012345678901')
+        self.failUnless(h == '12345678901234567890')
+
+    def value_stored(self, result, value):
+        self.stored -= 1
+        if self.stored == 0:
+            self.get_values()
+        
+    def store_values(self, result):
+        self.stored = 3
+        d = self.a.storeValue(sha.new('4045').digest(), str(4045*3))
+        d.addCallback(self.value_stored, 4045)
+        d = self.a.storeValue(sha.new('4044').digest(), str(4044*2))
+        d.addCallback(self.value_stored, 4044)
+        d = self.b.storeValue(sha.new('4045').digest(), str(4045*2))
+        d.addCallback(self.value_stored, 4045)
+
+    def check_values(self, result, values):
+        self.checked -= 1
+        self.failUnless(len(result) == len(values))
+        for v in result:
+            self.failUnless(v in values)
+        if self.checked == 0:
+            self.lastDefer.callback(1)
+    
+    def get_values(self):
+        self.checked = 4
+        d = self.a.getValue(sha.new('4044').digest())
+        d.addCallback(self.check_values, [str(4044*2)])
+        d = self.b.getValue(sha.new('4044').digest())
+        d.addCallback(self.check_values, [str(4044*2)])
+        d = self.a.getValue(sha.new('4045').digest())
+        d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
+        d = self.b.getValue(sha.new('4045').digest())
+        d.addCallback(self.check_values, [str(4045*2), str(4045*3)])
+
+    def test_store(self):
+        from twisted.internet.base import DelayedCall
+        DelayedCall.debug = True
+        self.lastDefer = defer.Deferred()
+        d = self.a.join()
+        d.addCallback(self.node_join)
+        d.addCallback(self.store_values)
+        return self.lastDefer
+
+    def tearDown(self):
+        self.a.leave()
+        try:
+            os.unlink(self.a.khashmir.store.db)
+        except:
+            pass
+        self.b.leave()
+        try:
+            os.unlink(self.b.khashmir.store.db)
+        except:
+            pass
+
+class TestMultiDHT(unittest.TestCase):
+    """More complicated 20-node tests for the DHT."""
+    
+    timeout = 60
+    num = 20
+    DHT_DEFAULTS = {'PORT': 9977, 'K': 8, 'HASH_LENGTH': 160,
+                    'CHECKPOINT_INTERVAL': 300, 'CONCURRENT_REQS': 4,
+                    'STORE_REDUNDANCY': 3, 'RETRIEVE_VALUES': -10000,
+                    'MAX_FAILURES': 3,
+                    'MIN_PING_INTERVAL': 900,'BUCKET_STALENESS': 3600,
+                    'KEY_EXPIRE': 3600, 'SPEW': False, }
+
+    def setUp(self):
+        self.l = []
+        self.startport = 4081
+        for i in range(self.num):
+            self.l.append(DHT())
+            self.l[i].config = self.DHT_DEFAULTS.copy()
+            self.l[i].config['PORT'] = self.startport + i
+            self.l[i].bootstrap = ["127.0.0.1:" + str(self.startport)]
+            self.l[i].cache_dir = '/tmp'
+        self.l[0].bootstrap_node = True
+        
+    def node_join(self, result, next_node):
+        d = self.l[next_node].join()
+        if next_node + 1 < len(self.l):
+            d.addCallback(self.node_join, next_node + 1)
+        else:
+            d.addCallback(self.lastDefer.callback)
+    
+    def test_join(self):
+        self.timeout = 2
+        self.lastDefer = defer.Deferred()
+        d = self.l[0].join()
+        d.addCallback(self.node_join, 1)
+        return self.lastDefer
+        
+    def store_values(self, result, i = 0, j = 0):
+        if j > i:
+            j -= i+1
+            i += 1
+        if i == len(self.l):
+            self.get_values()
+        else:
+            d = self.l[j].storeValue(sha.new(str(self.startport+i)).digest(), str((self.startport+i)*(j+1)))
+            d.addCallback(self.store_values, i, j+1)
+    
+    def get_values(self, result = None, check = None, i = 0, j = 0):
+        if result is not None:
+            self.failUnless(len(result) == len(check))
+            for v in result:
+                self.failUnless(v in check)
+        if j >= len(self.l):
+            j -= len(self.l)
+            i += 1
+        if i == len(self.l):
+            self.lastDefer.callback(1)
+        else:
+            d = self.l[i].getValue(sha.new(str(self.startport+j)).digest())
+            check = []
+            for k in range(self.startport+j, (self.startport+j)*(j+1)+1, self.startport+j):
+                check.append(str(k))
+            d.addCallback(self.get_values, check, i, j + random.randrange(1, min(len(self.l), 10)))
+
+    def store_join(self, result, next_node):
+        d = self.l[next_node].join()
+        if next_node + 1 < len(self.l):
+            d.addCallback(self.store_join, next_node + 1)
+        else:
+            d.addCallback(self.store_values)
+    
+    def test_store(self):
+        from twisted.internet.base import DelayedCall
+        DelayedCall.debug = True
+        self.lastDefer = defer.Deferred()
+        d = self.l[0].join()
+        d.addCallback(self.store_join, 1)
+        return self.lastDefer
 
-        self.khashmir.storeValueForKey(key, value)
+    def tearDown(self):
+        for i in self.l:
+            try:
+                i.leave()
+                os.unlink(i.khashmir.store.db)
+            except:
+                pass