relay: add database, not used yet

.gitignore

@@ -55,3 +55,4 @@ docs/_build/
 # PyBuilder
 target/
 /twistd.pid
+/relay.sqlite

src/wormhole/database.py

@@ -0,0 +1,40 @@
+import os, sys
+import sqlite3
+from pkg_resources import resource_string
+
+class DBError(Exception):
+    pass
+
+def get_schema(version):
+    return resource_string("wormhole", "db-schemas/v%d.sql" % version)
+
+def get_db(dbfile, stderr=sys.stderr):
+    """Open or create the given db file. The parent directory must exist.
+    Returns the db connection object, or raises DBError.
+    """
+
+    must_create = not os.path.exists(dbfile)
+    try:
+        db = sqlite3.connect(dbfile)
+    except (EnvironmentError, sqlite3.OperationalError), e:
+        raise DBError("Unable to create/open db file %s: %s" % (dbfile, e))
+    db.row_factory = sqlite3.Row
+
+    VERSION = 1
+    if must_create:
+        schema = get_schema(VERSION)
+        db.executescript(schema)
+        db.execute("INSERT INTO version (version) VALUES (?)", (VERSION,))
+        db.commit()
+
+    try:
+        version = db.execute("SELECT version FROM version").fetchone()[0]
+    except sqlite3.DatabaseError, e:
+        # this indicates that the file is not a compatible database format.
+        # Perhaps it was created with an old version, or it might be junk.
+        raise DBError("db file is unusable: %s" % e)
+
+    if version != VERSION:
+        raise DBError("Unable to handle db version %s" % version)
+
+    return db

src/wormhole/db-schemas/v1.sql

@@ -0,0 +1,18 @@
+
+-- note: anything which isn't an boolean, integer, or human-readable unicode
+-- string, (i.e. binary strings) will be stored as hex
+
+CREATE TABLE `version`
+(
+ `version` INTEGER -- contains one row, set to 1
+);
+
+CREATE TABLE `messages`
+(
+ `channel_id` INTEGER,
+ `side` VARCHAR,
+ `msgnum` VARCHAR, -- not numeric, more of a PAKE-phase indicator string
+ `message` VARCHAR,
+ `when` INTEGER
+);
+CREATE INDEX `lookup` ON `messages` (`channel_id`, `side`, `msgnum`);

src/wormhole/servers/relay.py

@@ -5,6 +5,7 @@ from twisted.internet import protocol
 from twisted.application import strports, service, internet
 from twisted.web import server, static, resource, http
 from .. import __version__
+from ..database import get_db
 
 SECONDS = 1.0
 MINUTE = 60*SECONDS
@@ -58,10 +59,11 @@ class EventsProtocol:
 class Channel(resource.Resource):
     isLeaf = True # I handle /CHANNEL-ID/*
 
-    def __init__(self, channel_id, relay, welcome):
+    def __init__(self, channel_id, relay, db, welcome):
         resource.Resource.__init__(self)
         self.channel_id = channel_id
         self.relay = relay
+        self.db = db
         self.welcome = welcome
         self.expire_at = time.time() + CHANNEL_EXPIRATION_TIME
         self.sides = set()
@@ -145,7 +147,7 @@ class Allocator(resource.Resource):
         #side = request.postpath[0]
         channel_id = self.relay.allocate_channel_id()
         self.relay.channels[channel_id] = Channel(channel_id, self.relay,
-                                                  self.welcome)
+                                                  self.relay.db, self.welcome)
         log.msg("allocated #%d, now have %d channels" %
                 (channel_id, len(self.relay.channels)))
         request.setHeader("content-type", "application/json; charset=utf-8")
@@ -163,8 +165,9 @@ class ChannelList(resource.Resource):
                            "channel-ids": self.channel_ids})+"\n"
 
 class Relay(resource.Resource):
-    def __init__(self, welcome):
+    def __init__(self, db, welcome):
         resource.Resource.__init__(self)
+        self.db = db
         self.welcome = welcome
         self.channels = {}
 
@@ -205,7 +208,8 @@ class Relay(resource.Resource):
         if not channel_id in self.channels:
             log.msg("claimed #%d, now have %d channels" %
                     (channel_id, len(self.channels)))
-            self.channels[channel_id] = Channel(channel_id, self, self.welcome)
+            self.channels[channel_id] = Channel(channel_id, self, self.db,
+                                                self.welcome)
         return self.channels[channel_id]
 
     def free_child(self, channel_id):
@@ -342,7 +346,7 @@ class Root(resource.Resource):
 class RelayServer(service.MultiService):
     def __init__(self, relayport, transitport, advertise_version):
         service.MultiService.__init__(self)
-
+        self.db = get_db("relay.sqlite")
         welcome = {
             "current_version": __version__,
             # adding .motd will cause all clients to display the message,
@@ -358,7 +362,7 @@ class RelayServer(service.MultiService):
         site = server.Site(self.root)
         self.relayport_service = strports.service(relayport, site)
         self.relayport_service.setServiceParent(self)
-        self.relay = Relay(welcome) # accessible from tests
+        self.relay = Relay(self.db, welcome) # accessible from tests
         self.root.putChild("wormhole-relay", self.relay)
         t = internet.TimerService(5*MINUTE, self.relay.prune_old_channels)
         t.setServiceParent(self)