213 lines
8.1 KiB
Python
213 lines
8.1 KiB
Python
#!/usr/bin/env python
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#
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# This library is free software, distributed under the terms of
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# the GNU Lesser General Public License Version 3, or any later version.
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# See the COPYING file included in this archive
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#
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# The docstrings in this module contain epytext markup; API documentation
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# may be created by processing this file with epydoc: http://epydoc.sf.net
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import UserDict
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#import sqlite3
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import cPickle as pickle
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import time
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import os
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import constants
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class DataStore(UserDict.DictMixin):
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""" Interface for classes implementing physical storage (for data
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published via the "STORE" RPC) for the Kademlia DHT
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@note: This provides an interface for a dict-like object
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"""
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def keys(self):
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""" Return a list of the keys in this data store """
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# def lastPublished(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was last published """
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# def originalPublisherID(self, key):
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# """ Get the original publisher of the data's node ID
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#
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# @param key: The key that identifies the stored data
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# @type key: str
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#
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# @return: Return the node ID of the original publisher of the
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# C{(key, value)} pair identified by C{key}.
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# """
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# def originalPublishTime(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was originally published """
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# def setItem(self, key, value, lastPublished, originallyPublished, originalPublisherID):
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# """ Set the value of the (key, value) pair identified by C{key};
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# this should set the "last published" value for the (key, value)
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# pair to the current time
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# """
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def addPeerToBlob(self, key, value, lastPublished, originallyPublished, originalPublisherID):
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pass
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# def __getitem__(self, key):
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# """ Get the value identified by C{key} """
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# def __setitem__(self, key, value):
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# """ Convenience wrapper to C{setItem}; this accepts a tuple in the
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# format: (value, lastPublished, originallyPublished, originalPublisherID) """
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# self.setItem(key, *value)
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# def __delitem__(self, key):
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# """ Delete the specified key (and its value) """
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class DictDataStore(DataStore):
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""" A datastore using an in-memory Python dictionary """
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def __init__(self):
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# Dictionary format:
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# { <key>: (<value>, <lastPublished>, <originallyPublished> <originalPublisherID>) }
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self._dict = {}
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def keys(self):
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""" Return a list of the keys in this data store """
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return self._dict.keys()
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# def lastPublished(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was last published """
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# return self._dict[key][1]
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# def originalPublisherID(self, key):
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# """ Get the original publisher of the data's node ID
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#
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# @param key: The key that identifies the stored data
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# @type key: str
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#
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# @return: Return the node ID of the original publisher of the
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# C{(key, value)} pair identified by C{key}.
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# """
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# return self._dict[key][3]
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# def originalPublishTime(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was originally published """
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# return self._dict[key][2]
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def removeExpiredPeers(self):
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now = int(time.time())
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def notExpired(peer):
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if (now - peer[2]) > constants.dataExpireTimeout:
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return False
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return True
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for key in self._dict.keys():
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unexpired_peers = filter(notExpired, self._dict[key])
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self._dict[key] = unexpired_peers
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def hasPeersForBlob(self, key):
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if key in self._dict and len(self._dict[key]) > 0:
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return True
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return False
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def addPeerToBlob(self, key, value, lastPublished, originallyPublished, originalPublisherID):
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if key in self._dict:
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self._dict[key].append((value, lastPublished, originallyPublished, originalPublisherID))
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else:
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self._dict[key] = [(value, lastPublished, originallyPublished, originalPublisherID)]
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def getPeersForBlob(self, key):
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if key in self._dict:
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return [val[0] for val in self._dict[key]]
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# def setItem(self, key, value, lastPublished, originallyPublished, originalPublisherID):
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# """ Set the value of the (key, value) pair identified by C{key};
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# this should set the "last published" value for the (key, value)
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# pair to the current time
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# """
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# self._dict[key] = (value, lastPublished, originallyPublished, originalPublisherID)
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# def __getitem__(self, key):
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# """ Get the value identified by C{key} """
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# return self._dict[key][0]
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# def __delitem__(self, key):
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# """ Delete the specified key (and its value) """
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# del self._dict[key]
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#class SQLiteDataStore(DataStore):
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# """ Example of a SQLite database-based datastore
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# """
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# def __init__(self, dbFile=':memory:'):
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# """
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# @param dbFile: The name of the file containing the SQLite database; if
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# unspecified, an in-memory database is used.
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# @type dbFile: str
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# """
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# createDB = not os.path.exists(dbFile)
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# self._db = sqlite3.connect(dbFile)
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# self._db.isolation_level = None
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# self._db.text_factory = str
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# if createDB:
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# self._db.execute('CREATE TABLE data(key, value, lastPublished, originallyPublished, originalPublisherID)')
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# self._cursor = self._db.cursor()
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# def keys(self):
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# """ Return a list of the keys in this data store """
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# keys = []
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# try:
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# self._cursor.execute("SELECT key FROM data")
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# for row in self._cursor:
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# keys.append(row[0].decode('hex'))
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# finally:
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# return keys
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# def lastPublished(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was last published """
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# return int(self._dbQuery(key, 'lastPublished'))
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# def originalPublisherID(self, key):
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# """ Get the original publisher of the data's node ID
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# @param key: The key that identifies the stored data
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# @type key: str
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# @return: Return the node ID of the original publisher of the
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# C{(key, value)} pair identified by C{key}.
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# """
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# return self._dbQuery(key, 'originalPublisherID')
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# def originalPublishTime(self, key):
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# """ Get the time the C{(key, value)} pair identified by C{key}
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# was originally published """
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# return int(self._dbQuery(key, 'originallyPublished'))
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# def setItem(self, key, value, lastPublished, originallyPublished, originalPublisherID):
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# # Encode the key so that it doesn't corrupt the database
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# encodedKey = key.encode('hex')
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# self._cursor.execute("select key from data where key=:reqKey", {'reqKey': encodedKey})
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# if self._cursor.fetchone() == None:
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# self._cursor.execute('INSERT INTO data(key, value, lastPublished, originallyPublished, originalPublisherID) VALUES (?, ?, ?, ?, ?)', (encodedKey, buffer(pickle.dumps(value, pickle.HIGHEST_PROTOCOL)), lastPublished, originallyPublished, originalPublisherID))
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# else:
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# self._cursor.execute('UPDATE data SET value=?, lastPublished=?, originallyPublished=?, originalPublisherID=? WHERE key=?', (buffer(pickle.dumps(value, pickle.HIGHEST_PROTOCOL)), lastPublished, originallyPublished, originalPublisherID, encodedKey))
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# def _dbQuery(self, key, columnName, unpickle=False):
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# try:
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# self._cursor.execute("SELECT %s FROM data WHERE key=:reqKey" % columnName, {'reqKey': key.encode('hex')})
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# row = self._cursor.fetchone()
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# value = str(row[0])
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# except TypeError:
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# raise KeyError, key
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# else:
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# if unpickle:
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# return pickle.loads(value)
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# else:
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# return value
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# def __getitem__(self, key):
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# return self._dbQuery(key, 'value', unpickle=True)
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# def __delitem__(self, key):
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# self._cursor.execute("DELETE FROM data WHERE key=:reqKey", {'reqKey': key.encode('hex')})
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