+
+"""Manage all delaings with the DHT.
+
+@var DHT_PIECES: the maximum number of pieces to store with our contact info
+ in the DHT
+@var TORRENT_PIECES: the maximum number of pieces to store as a separate entry
+ in the DHT
+"""
+
+import sha
+
+from twisted.internet import reactor
+from twisted.python import log
+
+from interfaces import IDHTStats
+from apt_p2p_conf import config
+from Hash import HashObject
+from util import findMyIPAddr, compact
+
+DHT_PIECES = 4
+TORRENT_PIECES = 70
+
+class DHT:
+ """Manages all the requests to a DHT.
+
+ @type dhtClass: L{interfaces.IDHT}
+ @ivar dhtClass: the DHT class to use
+ @type db: L{db.DB}
+ @ivar db: the database to use for tracking files and hashes
+ @type dht: L{interfaces.IDHT}
+ @ivar dht: the DHT instance
+ @type my_contact: C{string}
+ @ivar my_contact: the 6-byte compact peer representation of this peer's
+ download information (IP address and port)
+ """
+
+ def __init__(self, dhtClass, db):
+ """Initialize the instance.
+
+ @type dhtClass: L{interfaces.IDHT}
+ @param dhtClass: the DHT class to use
+ """
+ self.dhtClass = dhtClass
+ self.db = db
+ self.my_contact = None
+
+ def start(self):
+ self.dht = self.dhtClass()
+ self.dht.loadConfig(config, config.get('DEFAULT', 'DHT'))
+ df = self.dht.join()
+ df.addCallbacks(self.joinComplete, self.joinError)
+ return df
+
+ def joinComplete(self, result):
+ """Complete the DHT join process and determine our download information.
+
+ Called by the DHT when the join has been completed with information
+ on the external IP address and port of this peer.
+ """
+ my_addr = findMyIPAddr(result,
+ config.getint(config.get('DEFAULT', 'DHT'), 'PORT'),
+ config.getboolean('DEFAULT', 'LOCAL_OK'))
+ if not my_addr:
+ raise RuntimeError, "IP address for this machine could not be found"
+ self.my_contact = compact(my_addr, config.getint('DEFAULT', 'PORT'))
+ self.nextRefresh = reactor.callLater(60, self.refreshFiles)
+ return (my_addr, config.getint('DEFAULT', 'PORT'))
+
+ def joinError(self, failure):
+ """Joining the DHT has failed."""
+ log.msg("joining DHT failed miserably")
+ log.err(failure)
+ return failure
+
+ def refreshFiles(self, result = None, hashes = {}):
+ """Refresh any files in the DHT that are about to expire."""
+ if result is not None:
+ log.msg('Storage resulted in: %r' % result)
+
+ if not hashes:
+ expireAfter = config.gettime('DEFAULT', 'KEY_REFRESH')
+ hashes = self.db.expiredHashes(expireAfter)
+ if len(hashes.keys()) > 0:
+ log.msg('Refreshing the keys of %d DHT values' % len(hashes.keys()))
+
+ delay = 60
+ if hashes:
+ delay = 3
+ raw_hash = hashes.keys()[0]
+ self.db.refreshHash(raw_hash)
+ hash = HashObject(raw_hash, pieces = hashes[raw_hash]['pieces'])
+ del hashes[raw_hash]
+ storeDefer = self.store(hash)
+ storeDefer.addBoth(self.refreshFiles, hashes)
+
+ if self.nextRefresh.active():
+ self.nextRefresh.reset(delay)
+ else:
+ self.nextRefresh = reactor.callLater(delay, self.refreshFiles, None, hashes)
+
+ def getStats(self):
+ """Retrieve the formatted statistics for the DHT.
+
+ @rtype: C{string}
+ @return: the formatted HTML page containing the statistics
+ """
+ if IDHTStats.implementedBy(self.dhtClass):
+ return self.dht.getStats()
+ return "<p>DHT doesn't support statistics\n"
+
+ def get(self, key):
+ """Retrieve a hash's value from the DHT."""
+ return self.dht.getValue(key)
+
+ def store(self, hash):
+ """Add a hash for a file to the DHT.
+
+ Sets the key and value from the hash information, and tries to add
+ it to the DHT.
+ """
+ key = hash.digest()
+ value = {'c': self.my_contact}
+ pieces = hash.pieceDigests()
+
+ # Determine how to store any piece data
+ if len(pieces) <= 1:
+ pass
+ elif len(pieces) <= DHT_PIECES:
+ # Short enough to be stored with our peer contact info
+ value['t'] = {'t': ''.join(pieces)}
+ elif len(pieces) <= TORRENT_PIECES:
+ # Short enough to be stored in a separate key in the DHT
+ value['h'] = sha.new(''.join(pieces)).digest()
+ else:
+ # Too long, must be served up by our peer HTTP server
+ value['l'] = sha.new(''.join(pieces)).digest()
+
+ storeDefer = self.dht.storeValue(key, value)
+ storeDefer.addCallbacks(self._store_done, self._store_error,
+ callbackArgs = (hash, ), errbackArgs = (hash.digest(), ))
+ return storeDefer
+
+ def _store_done(self, result, hash):
+ """Add a key/value pair for the pieces of the file to the DHT (if necessary)."""
+ log.msg('Added %s to the DHT: %r' % (hash.hexdigest(), result))
+ pieces = hash.pieceDigests()
+ if len(pieces) > DHT_PIECES and len(pieces) <= TORRENT_PIECES:
+ # Add the piece data key and value to the DHT
+ key = sha.new(''.join(pieces)).digest()
+ value = {'t': ''.join(pieces)}
+
+ storeDefer = self.dht.storeValue(key, value)
+ storeDefer.addCallbacks(self._store_torrent_done, self._store_error,
+ callbackArgs = (key, ), errbackArgs = (key, ))
+ return storeDefer
+ return result
+
+ def _store_torrent_done(self, result, key):
+ """Adding the pieces to the DHT is complete."""
+ log.msg('Added torrent string %r to the DHT: %r' % (key, result))
+ return result
+
+ def _store_error(self, err, key):
+ """Adding to the DHT failed."""
+ log.msg('An error occurred adding %r to the DHT: %r' % (key, err))
+ return err
+
\ No newline at end of file
projects / quix0rs-apt-p2p.git / commitdiff