From 2e90d76784ea1a297dcdb1d95a354402a881337a Mon Sep 17 00:00:00 2001
From: burris <burris>
Date: Tue, 3 Dec 2002 03:49:58 +0000
Subject: [PATCH] now we store and retrieve node information from our
 database...

---
 const.py    |  5 +++-
 khashmir.py | 79 ++++++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 70 insertions(+), 14 deletions(-)

diff --git a/const.py b/const.py
index 4926f00..d81ecbd 100644
--- a/const.py
+++ b/const.py
@@ -7,12 +7,15 @@ main.installReactor(reactor)
 # magic id to use before we know a peer's id
 NULL_ID =  20 * '\0'
 
-# Kademlia "K" constant
+# Kademlia "K" constant, this should be an even number
 K = 8
 
 # SHA1 is 160 bits long
 HASH_LENGTH = 160
 
+# checkpoint every this many seconds
+CHECKPOINT_INTERVAL = 60 * 15 # fifteen minutes
+
 
 ### SEARCHING/STORING
 # concurrent xmlrpc calls per find node/value request!
diff --git a/khashmir.py b/khashmir.py
index a9bc5b5..5e7c717 100644
--- a/khashmir.py
+++ b/khashmir.py
@@ -30,15 +30,41 @@ class Khashmir(xmlrpc.XMLRPC):
 	__slots__ = ('listener', 'node', 'table', 'store', 'app', 'last')
 	def __init__(self, host, port, db='khashmir.db'):
 		self.setup(host, port, db)
+		
 	def setup(self, host, port, db='khashmir.db'):
-		self.node = Node().init(newID(), host, port)
+		self.findDB(db)
+		self.node = self.loadSelfNode(host, port)
 		self.table = KTable(self.node)
+		self.loadRoutingTable()
 		self.app = Application("xmlrpc")
 		self.app.listenTCP(port, server.Site(self))
-		self.findDB(db)
 		self.last = time.time()
 		KeyExpirer(store=self.store)
-
+		reactor.callLater(const.CHECKPOINT_INTERVAL, self.checkpoint)
+		self.refreshTable(force=1)
+		
+	def loadSelfNode(self, host, port):
+		c = self.store.cursor()
+		c.execute('select id from self where num = 0;')
+		if c.rowcount > 0:
+			id = c.fetchone()[0].decode('base64')
+		else:
+			id = newID()
+		return Node().init(id, host, port)
+		
+	def saveSelfNode(self):
+		self.store.autocommit = 0
+		c = self.store.cursor()
+		c.execute('delete from self where num = 0;')
+		c.execute("insert into self values (0, '%s');" % self.node.id.encode('base64'))
+		self.store.commit()
+		self.store.autocommit = 1
+		
+	def checkpoint(self):
+		self.saveSelfNode()
+		self.dumpRoutingTable()
+		reactor.callLater(const.CHECKPOINT_INTERVAL, self.checkpoint)
+		
 	def findDB(self, db):
 		import os
 		try:
@@ -65,10 +91,37 @@ class Khashmir(xmlrpc.XMLRPC):
 			create index kv_timestamp on kv(time);
 			
 			create table nodes (id text primary key, host text, port number);
+			
+			create table self (num number primary key, id text);
 			"""
 		c = self.store.cursor()
 		c.execute(s)
 
+	def dumpRoutingTable(self):
+		"""
+			save routing table nodes to the database
+		"""
+		self.store.autocommit = 0;
+		c = self.store.cursor()
+		c.execute("delete from nodes where id not NULL;")
+		for bucket in self.table.buckets:
+			for node in bucket.l:
+				d = node.senderDict()
+				c.execute("insert into nodes values ('%s', '%s', '%s');" % (d['id'], d['host'], d['port']))
+		self.store.commit()
+		self.store.autocommit = 1;
+		
+	def loadRoutingTable(self):
+		"""
+			load routing table nodes from database
+			it's usually a good idea to call refreshTable(force=1) after loading the table
+		"""
+		c = self.store.cursor()
+		c.execute("select * from nodes;")
+		for rec in c.fetchall():
+			n = Node().initWithDict({'id':rec[0], 'host':rec[1], 'port':int(rec[2])})
+			self.table.insertNode(n, contacted=0)
+			
 	def render(self, request):
 		"""
 			Override the built in render so we can have access to the request object!
@@ -182,14 +235,14 @@ class Khashmir(xmlrpc.XMLRPC):
 		"""
 		df = node.ping(self.node.senderDict())
 		## these are the callbacks we use when we issue a PING
-		def _pongHandler(args, id=node.id, host=node.host, port=node.port, table=self.table):
+		def _pongHandler(args, node=node, table=self.table):
 			l, sender = args
-			if id != const.NULL_ID and id != sender['id'].decode('base64'):
+			if node.id != const.NULL_ID and node.id != sender['id'].decode('base64'):
 				# whoah, got response from different peer than we were expecting
-				pass
+				self.table.invalidateNode(node)
 			else:
-				sender['host'] = host
-				sender['port'] = port
+				sender['host'] = node.host
+				sender['port'] = node.port
 				n = Node().initWithDict(sender)
 				table.insertNode(n)
 				return
@@ -207,15 +260,15 @@ class Khashmir(xmlrpc.XMLRPC):
 		id = self.node.id[:-1] + chr((ord(self.node.id[-1]) + 1) % 256)
 		self.findNode(id, callback)
 
-	def refreshTable(self):
+	def refreshTable(self, force=0):
 		"""
-			
+			force=1 will refresh table regardless of last bucket access time
 		"""
 		def callback(nodes):
 			pass
 	
 		for bucket in self.table.buckets:
-			if time.time() - bucket.lastAccessed >= const.BUCKET_STALENESS:
+			if force or (time.time() - bucket.lastAccessed >= const.BUCKET_STALENESS):
 				id = newIDInRange(bucket.min, bucket.max)
 				self.findNode(id, callback)
 
@@ -286,12 +339,12 @@ class Khashmir(xmlrpc.XMLRPC):
 			return {'nodes' : nodes}, self.node.senderDict()
 #------ testing
 
-def test_build_net(quiet=0, peers=24, host='localhost',  pause=0):
+def test_build_net(quiet=0, peers=24, host='localhost',  pause=0, startport=2001):
 	from whrandom import randrange
 	import threading
 	import thread
 	import sys
-	port = 2001
+	port = startport
 	l = []
 		
 	if not quiet:
-- 
2.39.2