--- /dev/null
+
+"""An sqlite database for storing nodes and key/value pairs."""
+
+from datetime import datetime, timedelta
+from pysqlite2 import dbapi2 as sqlite
+from binascii import a2b_base64, b2a_base64
+from time import sleep
+import os
+
+from twisted.trial import unittest
+
+class DBExcept(Exception):
+ pass
+
+class khash(str):
+ """Dummy class to convert all hashes to base64 for storing in the DB."""
+
+class dht_value(str):
+ """Dummy class to convert all DHT values to base64 for storing in the DB."""
+
+# Initialize the database to work with 'khash' objects (binary strings)
+sqlite.register_adapter(khash, b2a_base64)
+sqlite.register_converter("KHASH", a2b_base64)
+sqlite.register_converter("khash", a2b_base64)
+
+# Initialize the database to work with DHT values (binary strings)
+sqlite.register_adapter(dht_value, b2a_base64)
+sqlite.register_converter("DHT_VALUE", a2b_base64)
+sqlite.register_converter("dht_value", a2b_base64)
+
+class DB:
+ """An sqlite database for storing persistent node info and key/value pairs.
+
+ @type db: C{string}
+ @ivar db: the database file to use
+ @type conn: L{pysqlite2.dbapi2.Connection}
+ @ivar conn: an open connection to the sqlite database
+ """
+
+ def __init__(self, db):
+ """Load or create the database file.
+
+ @type db: C{string}
+ @param db: the database file to use
+ """
+ self.db = db
+ try:
+ os.stat(db)
+ except OSError:
+ self._createNewDB(db)
+ else:
+ self._loadDB(db)
+ if sqlite.version_info < (2, 1):
+ sqlite.register_converter("TEXT", str)
+ sqlite.register_converter("text", str)
+ else:
+ self.conn.text_factory = str
+
+ #{ Loading the DB
+ def _loadDB(self, db):
+ """Open a new connection to the existing database file"""
+ try:
+ self.conn = sqlite.connect(database=db, detect_types=sqlite.PARSE_DECLTYPES)
+ except:
+ import traceback
+ raise DBExcept, "Couldn't open DB", traceback.format_exc()
+
+ def _createNewDB(self, db):
+ """Open a connection to a new database and create the necessary tables."""
+ self.conn = sqlite.connect(database=db, detect_types=sqlite.PARSE_DECLTYPES)
+ c = self.conn.cursor()
+ c.execute("CREATE TABLE kv (key KHASH, value DHT_VALUE, last_refresh TIMESTAMP, "+
+ "PRIMARY KEY (key, value))")
+ c.execute("CREATE INDEX kv_key ON kv(key)")
+ c.execute("CREATE INDEX kv_last_refresh ON kv(last_refresh)")
+ c.execute("CREATE TABLE nodes (id KHASH PRIMARY KEY, host TEXT, port NUMBER)")
+ c.execute("CREATE TABLE self (num NUMBER PRIMARY KEY, id KHASH)")
+ self.conn.commit()
+
+ def close(self):
+ self.conn.close()
+
+ #{ This node's ID
+ def getSelfNode(self):
+ """Retrieve this node's ID from a previous run of the program."""
+ c = self.conn.cursor()
+ c.execute('SELECT id FROM self WHERE num = 0')
+ id = c.fetchone()
+ if id:
+ return id[0]
+ else:
+ return None
+
+ def saveSelfNode(self, id):
+ """Store this node's ID for a subsequent run of the program."""
+ c = self.conn.cursor()
+ c.execute("INSERT OR REPLACE INTO self VALUES (0, ?)", (khash(id),))
+ self.conn.commit()
+
+ #{ Routing table
+ def dumpRoutingTable(self, buckets):
+ """Save routing table nodes to the database."""
+ c = self.conn.cursor()
+ c.execute("DELETE FROM nodes WHERE id NOT NULL")
+ for bucket in buckets:
+ for node in bucket.l:
+ c.execute("INSERT INTO nodes VALUES (?, ?, ?)", (khash(node.id), node.host, node.port))
+ self.conn.commit()
+
+ def getRoutingTable(self):
+ """Load routing table nodes from database."""
+ c = self.conn.cursor()
+ c.execute("SELECT * FROM nodes")
+ return c.fetchall()
+
+ #{ Key/value pairs
+ def retrieveValues(self, key):
+ """Retrieve values from the database."""
+ c = self.conn.cursor()
+ c.execute("SELECT value FROM kv WHERE key = ?", (khash(key),))
+ l = []
+ rows = c.fetchall()
+ for row in rows:
+ l.append(row[0])
+ return l
+
+ def countValues(self, key):
+ """Count the number of values in the database."""
+ c = self.conn.cursor()
+ c.execute("SELECT COUNT(value) as num_values FROM kv WHERE key = ?", (khash(key),))
+ res = 0
+ row = c.fetchone()
+ if row:
+ res = row[0]
+ return res
+
+ def storeValue(self, key, value):
+ """Store or update a key and value."""
+ c = self.conn.cursor()
+ c.execute("INSERT OR REPLACE INTO kv VALUES (?, ?, ?)",
+ (khash(key), dht_value(value), datetime.now()))
+ self.conn.commit()
+
+ def expireValues(self, expireAfter):
+ """Expire older values after expireAfter seconds."""
+ t = datetime.now() - timedelta(seconds=expireAfter)
+ c = self.conn.cursor()
+ c.execute("DELETE FROM kv WHERE last_refresh < ?", (t, ))
+ self.conn.commit()
+
+class TestDB(unittest.TestCase):
+ """Tests for the khashmir database."""
+
+ timeout = 5
+ db = '/tmp/khashmir.db'
+ key = '\xca\xec\xb8\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'
+
+ def setUp(self):
+ self.store = DB(self.db)
+
+ def test_selfNode(self):
+ self.store.saveSelfNode(self.key)
+ self.failUnlessEqual(self.store.getSelfNode(), self.key)
+
+ def test_Value(self):
+ self.store.storeValue(self.key, self.key)
+ val = self.store.retrieveValues(self.key)
+ self.failUnlessEqual(len(val), 1)
+ self.failUnlessEqual(val[0], self.key)
+
+ def test_expireValues(self):
+ self.store.storeValue(self.key, self.key)
+ sleep(2)
+ self.store.storeValue(self.key, self.key+self.key)
+ self.store.expireValues(1)
+ val = self.store.retrieveValues(self.key)
+ self.failUnlessEqual(len(val), 1)
+ self.failUnlessEqual(val[0], self.key+self.key)
+
+ def test_RoutingTable(self):
+ class dummy:
+ id = self.key
+ host = "127.0.0.1"
+ port = 9977
+ def contents(self):
+ return (self.id, self.host, self.port)
+ dummy2 = dummy()
+ dummy2.id = '\xaa\xbb\xcc\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'
+ dummy2.host = '205.23.67.124'
+ dummy2.port = 12345
+ class bl:
+ def __init__(self):
+ self.l = []
+ bl1 = bl()
+ bl1.l.append(dummy())
+ bl2 = bl()
+ bl2.l.append(dummy2)
+ buckets = [bl1, bl2]
+ self.store.dumpRoutingTable(buckets)
+ rt = self.store.getRoutingTable()
+ self.failUnlessIn(dummy().contents(), rt)
+ self.failUnlessIn(dummy2.contents(), rt)
+
+ def tearDown(self):
+ self.store.close()
+ os.unlink(self.db)