apt_dht_Khashmir/db.py

   1
   2 from datetime import datetime, timedelta
   3 from pysqlite2 import dbapi2 as sqlite
   4 from binascii import a2b_base64, b2a_base64
   5 from time import sleep
   6 import os
   7
   8 from twisted.trial import unittest
   9
  10 class DBExcept(Exception):
  11     pass
  12
  13 class khash(str):
  14     """Dummy class to convert all hashes to base64 for storing in the DB."""
  15
  16 sqlite.register_adapter(khash, b2a_base64)
  17 sqlite.register_converter("KHASH", a2b_base64)
  18 sqlite.register_converter("khash", a2b_base64)
  19
  20 class DB:
  21     """Database access for storing persistent data."""
  22
  23     def __init__(self, db):
  24         self.db = db
  25         try:
  26             os.stat(db)
  27         except OSError:
  28             self._createNewDB(db)
  29         else:
  30             self._loadDB(db)
  31         if sqlite.version_info < (2, 1):
  32             sqlite.register_converter("TEXT", str)
  33             sqlite.register_converter("text", str)
  34         else:
  35             self.conn.text_factory = str
  36
  37     def _loadDB(self, db):
  38         try:
  39             self.conn = sqlite.connect(database=db, detect_types=sqlite.PARSE_DECLTYPES)
  40         except:
  41             import traceback
  42             raise DBExcept, "Couldn't open DB", traceback.format_exc()
  43
  44     def _createNewDB(self, db):
  45         self.conn = sqlite.connect(database=db, detect_types=sqlite.PARSE_DECLTYPES)
  46         c = self.conn.cursor()
  47         c.execute("CREATE TABLE kv (key KHASH, value TEXT, last_refresh TIMESTAMP, PRIMARY KEY (key, value))")
  48         c.execute("CREATE INDEX kv_key ON kv(key)")
  49         c.execute("CREATE INDEX kv_last_refresh ON kv(last_refresh)")
  50         c.execute("CREATE TABLE nodes (id KHASH PRIMARY KEY, host TEXT, port NUMBER)")
  51         c.execute("CREATE TABLE self (num NUMBER PRIMARY KEY, id KHASH)")
  52         self.conn.commit()
  53
  54     def getSelfNode(self):
  55         c = self.conn.cursor()
  56         c.execute('SELECT id FROM self WHERE num = 0')
  57         id = c.fetchone()
  58         if id:
  59             return id[0]
  60         else:
  61             return None
  62
  63     def saveSelfNode(self, id):
  64         c = self.conn.cursor()
  65         c.execute("INSERT OR REPLACE INTO self VALUES (0, ?)", (khash(id),))
  66         self.conn.commit()
  67
  68     def dumpRoutingTable(self, buckets):
  69         """
  70             save routing table nodes to the database
  71         """
  72         c = self.conn.cursor()
  73         c.execute("DELETE FROM nodes WHERE id NOT NULL")
  74         for bucket in buckets:
  75             for node in bucket.l:
  76                 c.execute("INSERT INTO nodes VALUES (?, ?, ?)", (khash(node.id), node.host, node.port))
  77         self.conn.commit()
  78
  79     def getRoutingTable(self):
  80         """
  81             load routing table nodes from database
  82             it's usually a good idea to call refreshTable(force=1) after loading the table
  83         """
  84         c = self.conn.cursor()
  85         c.execute("SELECT * FROM nodes")
  86         return c.fetchall()
  87
  88     def retrieveValues(self, key):
  89         """Retrieve values from the database."""
  90         c = self.conn.cursor()
  91         c.execute("SELECT value FROM kv WHERE key = ?", (khash(key),))
  92         l = []
  93         rows = c.fetchall()
  94         for row in rows:
  95             l.append(row[0])
  96         return l
  97
  98     def storeValue(self, key, value):
  99         """Store or update a key and value."""
 100         c = self.conn.cursor()
 101         c.execute("INSERT OR REPLACE INTO kv VALUES (?, ?, ?)",
 102                   (khash(key), value, datetime.now()))
 103         self.conn.commit()
 104
 105     def expireValues(self, expireAfter):
 106         """Expire older values after expireAfter seconds."""
 107         t = datetime.now() - timedelta(seconds=expireAfter)
 108         c = self.conn.cursor()
 109         c.execute("DELETE FROM kv WHERE last_refresh < ?", (t, ))
 110         self.conn.commit()
 111
 112     def refreshValues(self, expireAfter):
 113         """Find older values than expireAfter seconds to refresh.
 114
 115         @return: a list of the hash keys and a list of dictionaries with
 116             key of the value, value is the origination time
 117         """
 118         t = datetime.now() - timedelta(seconds=expireAfter)
 119         c = self.conn.cursor()
 120         c.execute("SELECT key, value, FROM kv WHERE last_refresh < ?", (t,))
 121         keys = []
 122         vals = []
 123         rows = c.fetchall()
 124         for row in rows:
 125             keys.append(row[0])
 126             vals.append({row[1]: row[2]})
 127         return keys, vals
 128
 129     def close(self):
 130         self.conn.close()
 131
 132 class TestDB(unittest.TestCase):
 133     """Tests for the khashmir database."""
 134
 135     timeout = 5
 136     db = '/tmp/khashmir.db'
 137     key = '\xca\xec\xb8\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'
 138
 139     def setUp(self):
 140         self.store = DB(self.db)
 141
 142     def test_selfNode(self):
 143         self.store.saveSelfNode(self.key)
 144         self.failUnlessEqual(self.store.getSelfNode(), self.key)
 145
 146     def test_Value(self):
 147         self.store.storeValue(self.key, 'foobar', datetime.now())
 148         val = self.store.retrieveValues(self.key)
 149         self.failUnlessEqual(len(val), 1)
 150         self.failUnlessEqual(val[0], 'foobar')
 151
 152     def test_expireValues(self):
 153         self.store.storeValue(self.key, 'foobar', datetime.now())
 154         sleep(2)
 155         self.store.storeValue(self.key, 'barfoo', datetime.now())
 156         self.store.expireValues(1)
 157         val = self.store.retrieveValues(self.key)
 158         self.failUnlessEqual(len(val), 1)
 159         self.failUnlessEqual(val[0], 'barfoo')
 160
 161     def test_refreshValues(self):
 162         self.store.storeValue(self.key, 'foobar', datetime.now())
 163         sleep(2)
 164         self.store.storeValue(self.key, 'barfoo', datetime.now())
 165         keys, vals = self.store.refreshValues(1)
 166         self.failUnlessEqual(len(keys), 1)
 167         self.failUnlessEqual(keys[0], self.key)
 168         self.failUnlessEqual(len(vals), 1)
 169         self.failUnlessEqual(len(vals[0].keys()), 1)
 170         self.failUnlessEqual(vals[0].keys()[0], 'foobar')
 171         val = self.store.retrieveValues(self.key)
 172         self.failUnlessEqual(len(val), 2)
 173
 174     def test_RoutingTable(self):
 175         class dummy:
 176             id = self.key
 177             host = "127.0.0.1"
 178             port = 9977
 179             def contents(self):
 180                 return (self.id, self.host, self.port)
 181         dummy2 = dummy()
 182         dummy2.id = '\xaa\xbb\xcc\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'
 183         dummy2.host = '205.23.67.124'
 184         dummy2.port = 12345
 185         class bl:
 186             def __init__(self):
 187                 self.l = []
 188         bl1 = bl()
 189         bl1.l.append(dummy())
 190         bl2 = bl()
 191         bl2.l.append(dummy2)
 192         buckets = [bl1, bl2]
 193         self.store.dumpRoutingTable(buckets)
 194         rt = self.store.getRoutingTable()
 195         self.failUnlessIn(dummy().contents(), rt)
 196         self.failUnlessIn(dummy2.contents(), rt)
 197
 198     def tearDown(self):
 199         self.store.close()
 200         os.unlink(self.db)