linting refactoring communicator(utils) and reduced TOCTOU issus with online peer picking

src/communicator/onlinepeers/clearofflinepeer.py

@@ -1,9 +1,13 @@
-'''
-    Onionr - Private P2P Communication
+"""Onionr - Private P2P Communication.
 
-    clear offline peer in a communicator instance
-'''
-'''
+clear offline peer in a communicator instance
+"""
+from typing import TYPE_CHECKING
+
+import logger
+if TYPE_CHECKING:
+    from communicator import OnionrCommunicatorDaemon
+"""
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
@@ -16,14 +20,16 @@
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
-'''
-import logger
-def clear_offline_peer(comm_inst):
-    '''Removes the longest offline peer to retry later'''
+"""
+
+
+def clear_offline_peer(comm_inst: 'OnionrCommunicatorDaemon'):
+    """Remove the longest offline peer to retry later."""
     try:
         removed = comm_inst.offlinePeers.pop(0)
     except IndexError:
         pass
     else:
-        logger.debug('Removed ' + removed + ' from offline list, will try them again.')
-    comm_inst.decrementThreadCount('clear_offline_peer')
+        logger.debug('Removed ' + removed +
+                     ' from offline list, will try them again.')
+    comm_inst.decrementThreadCount('clear_offline_peer')

src/communicator/onlinepeers/onlinepeers.py

@@ -1,11 +1,14 @@
-"""
-    Onionr - Private P2P Communication
+"""Onionr - Private P2P Communication.
 
-    get online peers in a communicator instance
+get online peers in a communicator instance
 """
 import time
+from typing import TYPE_CHECKING
+
 from etc import humanreadabletime
 import logger
+if TYPE_CHECKING:
+    from communicator import OnionrCommunicatorDaemon
 """
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -22,25 +25,25 @@ import logger
 """
 
 
-def get_online_peers(comm_inst):
-    """
-        Manages the comm_inst.onlinePeers attribute list,
-        ]connects to more peers if we have none connected
+def get_online_peers(comm_inst: 'OnionrCommunicatorDaemon'):
+    """Manage the comm_inst.onlinePeers attribute list.
+
+    Connect to more peers if we have none connected
     """
     config = comm_inst.config
     if config.get('general.offline_mode', False):
         comm_inst.decrementThreadCount('get_online_peers')
         return
     logger.debug('Refreshing peer pool...')
-    maxPeers = int(config.get('peers.max_connect', 10))
-    needed = maxPeers - len(comm_inst.onlinePeers)
+    max_peers = int(config.get('peers.max_connect', 10))
+    needed = max_peers - len(comm_inst.onlinePeers)
 
     last_seen = 'never'
     if not isinstance(comm_inst.lastNodeSeen, type(None)):
         last_seen = humanreadabletime.human_readable_time(
             comm_inst.lastNodeSeen)
 
-    for i in range(needed):
+    for _ in range(needed):
         if len(comm_inst.onlinePeers) == 0:
             comm_inst.connectNewPeer(useBootstrap=True)
         else:
@@ -50,8 +53,7 @@ def get_online_peers(comm_inst):
             break
     else:
         if len(comm_inst.onlinePeers) == 0:
-            logger.debug
-            ('Couldn\'t connect to any peers.' +
+            logger.debug('Couldn\'t connect to any peers.' +
              f' Last node seen {last_seen}  ago.')
         else:
             comm_inst.lastNodeSeen = time.time()

src/communicator/onlinepeers/pickonlinepeers.py

@@ -1,9 +1,12 @@
-'''
-    Onionr - Private P2P Communication
+"""
+Onionr - Private P2P Communication.
 
-    pick online peers in a communicator instance
-'''
-'''
+pick online peers in a communicator instance
+"""
+import secrets
+
+import onionrexceptions
+"""
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
@@ -16,17 +19,22 @@
 
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
-'''
-import secrets
+"""
+
+
 def pick_online_peer(comm_inst):
-    '''randomly picks peer from pool without bias (using secrets module)'''
+    """Randomly picks peer from pool without bias (using secrets module)."""
     ret_data = ''
+    peer_length = len(comm_inst.onlinePeers)
+    if peer_length <= 0:
+        raise onionrexceptions.OnlinePeerNeeded
+
     while True:
         peer_length = len(comm_inst.onlinePeers)
-        if peer_length <= 0:
-            break
+
         try:
-            # get a random online peer, securely. May get stuck in loop if network is lost or if all peers in pool magically disconnect at once
+            # Get a random online peer, securely.
+            # May get stuck in loop if network is lost or if all peers in pool magically disconnect at once
             ret_data = comm_inst.onlinePeers[secrets.randbelow(peer_length)]
         except IndexError:
             pass