Do not cache newsgroups in Server

lib/nntp/tiny/server.py

@@ -5,11 +5,10 @@ import socket
 import selectors
 import ssl
 
-from nntp.tiny.config    import Config, ConfigException
-from nntp.tiny.db        import Database
-from nntp.tiny.host      import Host
-from nntp.tiny.newsgroup import Newsgroup
-from nntp.tiny.session   import Session
+from nntp.tiny.config  import Config, ConfigException
+from nntp.tiny.db      import Database
+from nntp.tiny.host    import Host
+from nntp.tiny.session import Session
 
 class ServerCapability(enum.Flag):
     NONE = 0
@@ -20,7 +19,6 @@ class Server():
     def __init__(self, config: Config):
         self.config       = config
         self.capabilities = ServerCapability.NONE
-        self.newsgroups   = dict()
         self.sslctx       = None
 
         if config.section('listen').get('tls', 'no') == 'yes':
@@ -28,17 +26,9 @@ class Server():
             self.sslctx.load_cert_chain(config.get('tls', 'cert'),
                                         config.get('tls', 'key'))
 
-        self._init_newsgroups()
-
     def connect_to_db(self):
         return Database.connect(self.config.get('database', 'path'))
 
-    def _init_newsgroups(self):
-        db = self.connect_to_db()
-
-        for newsgroup in db.query(Newsgroup).each():
-            self.newsgroups[newsgroup.name.casefold()] = newsgroup
-
     def listen(self, host: str, port: int, af: int):
         listener = socket.socket(af, socket.SOCK_STREAM)
         listener.bind((host, port))

lib/nntp/tiny/session.py

@@ -47,6 +47,15 @@ class Session(Connection):
 
         super().__init__(sock)
 
+    def newsgroup(self, name: str):
+        return self.db.get(Newsgroup, {'name': name})
+
+    def each_newsgroup(self):
+        cr = self.db.query(Newsgroup)
+
+        for newsgroup in cr.each():
+            yield newsgroup
+
     def respond(self, code: ResponseCode, message: str=None, body=None):
         response = Response(code, message, body)
 
@@ -106,10 +115,10 @@ class Session(Connection):
         return self.respond(ResponseCode.NNTP_POST_PROHIBITED)
 
     def _cmd_group(self, name: str):
-        if name not in self.server.newsgroups:
-            return self.respond(ResponseCode.NNTP_NEWSGROUP_NOT_FOUND)
+        newsgroup = self.newsgroup(name)
 
-        newsgroup = self.server.newsgroups[name]
+        if newsgroup is None:
+            return self.respond(ResponseCode.NNTP_NEWSGROUP_NOT_FOUND)
 
         sql = """
             select
@@ -236,7 +245,7 @@ class Session(Connection):
         if len(args) == 0 and newsgroup is None:
             return self.respond(ResponseCode.NNTP_NEWSGROUP_NOT_SELECTED)
         elif len(args) > 0:
-            newsgroup = self.server.newsgroups.get(args[0])
+            newsgroup = self.newsgroup(args[0])
 
             if newsgroup is None:
                 return self.respond(ResponseCode.NNTP_NEWSGROUP_NOT_FOUND)
@@ -290,9 +299,7 @@ class Session(Connection):
     def _cmd_list_newsgroups(self):
         self.respond(ResponseCode.NNTP_INFORMATION_FOLLOWS)
 
-        for name in self.server.newsgroups:
-            newsgroup = self.server.newsgroups[name]
-
+        for newsgroup in self.each_newsgroup():
             self.print("%s %s" % (
                 newsgroup.name,
                 newsgroup.description
@@ -325,8 +332,7 @@ class Session(Connection):
 
         self.respond(ResponseCode.NNTP_INFORMATION_FOLLOWS)
 
-        for name in self.server.newsgroups:
-            newsgroup   = self.server.newsgroups[name]
+        for newsgroup in self.each_newsgroup():
             last_active = self._newsgroup_last_active(newsgroup)
 
             if now - last_active < datetime.timedelta(days=1):
@@ -337,9 +343,7 @@ class Session(Connection):
     def _cmd_list_active_times(self):
         self.respond(ResponseCode.NNTP_INFORMATION_FOLLOWS)
 
-        for name in self.server.newsgroups:
-            newsgroup = self.server.newsgroups[name]
-
+        for newsgroup in self.each_newsgroup():
             self.print("%s %d %s" % (
                 name,
                 newsgroup.created_on.timestamp(),
@@ -469,10 +473,8 @@ class Session(Connection):
                 and message.created_on >= ?
         """
 
-        for name in self.server.newsgroups:
-            if fnmatch.fnmatch(name, wildmat):
-                newsgroup = self.server.newsgroups[name]
-
+        for newsgroup in self.each_newsgroup():
+            if fnmatch.fnmatch(newsgroup.name, wildmat):
                 cr = self.db.execute(sql, (newsgroup.id, timestamp.isoformat()))
 
                 while True:
@@ -500,9 +502,7 @@ class Session(Connection):
 
         self.respond(ResponseCode.NNTP_GROUPS_NEW_FOLLOW)
 
-        for name in self.server.newsgroups:
-            newsgroup = self.server.newsgroups[name]
-
+        for newsgroup in self.each_newsgroup():
             self.print_newsgroup_summary(newsgroup, timestamp)
 
         return self.end()
@@ -703,12 +703,12 @@ class Session(Connection):
         newsgroups = list()
 
         for name in names:
-            newsgroup = self.server.newsgroups.get(name)
+            newsgroup = self.newsgroup(name)
 
             if newsgroup is None or not newsgroup.writable:
                 return ResponseCode.NNTP_POST_PROHIBITED
 
-            newsgroups.append(self.server.newsgroups[name])
+            newsgroups.append(newsgroup)
 
         if len(newsgroups) == 0:
             return ResponseCode.NNTP_POST_FAILED