Automatically refresh and expire the torrent status cache.

Stop at ratio was not working when no clients were connected, because
it was using a cached version of the torrent status, and never calling
for a refresh. When a client connected, it called for the refresh and
started working properly.

Closes: https://dev.deluge-torrent.org/ticket/3497
Closes: https://github.com/deluge-torrent/deluge/pull/369

3 files changed, 54 insertions, 20 deletions

diff --git a/deluge/core/torrent.py b/deluge/core/torrent.py
index 9a4af0b8a..57ec26f37 100644
--- a/deluge/core/torrent.py
+++ b/deluge/core/torrent.py
@@ -16,6 +16,8 @@ Attributes:
 import logging
 import os
 import socket
+import time
+from typing import Optional
 from urllib.parse import urlparse
 
 from twisted.internet.defer import Deferred, DeferredList
@@ -234,7 +236,8 @@ class Torrent:
         self.handle = handle
 
         self.magnet = magnet
-        self.status = self.handle.status()
+        self._status: Optional['lt.torrent_status'] = None
+        self._status_last_update: float = 0.0
 
         self.torrent_info = self.handle.torrent_file()
         self.has_metadata = self.status.has_metadata
@@ -267,7 +270,6 @@ class Torrent:
         self.prev_status = {}
         self.waiting_on_folder_rename = []
 
-        self.update_status(self.handle.status())
         self._create_status_funcs()
         self.set_options(self.options)
         self.update_state()
@@ -641,7 +643,7 @@ class Torrent:
 
     def update_state(self):
         """Updates the state, based on libtorrent's torrent state"""
-        status = self.handle.status()
+        status = self.get_lt_status()
         session_paused = component.get('Core').session.is_paused()
         old_state = self.state
         self.set_status_message()
@@ -709,7 +711,7 @@ class Torrent:
             restart_to_resume (bool, optional): Prevent resuming clearing the error, only restarting
                 session can resume.
         """
-        status = self.handle.status()
+        status = self.get_lt_status()
         self._set_handle_flags(
             flag=lt.torrent_flags.auto_managed,
             set_flag=False,
@@ -1024,7 +1026,7 @@ class Torrent:
             dict: a dictionary of the status keys and their values
         """
         if update:
-            self.update_status(self.handle.status())
+            self.get_lt_status()
 
         if all_keys:
             keys = list(self.status_funcs)
@@ -1054,13 +1056,35 @@ class Torrent:
 
         return status_dict
 
-    def update_status(self, status):
+    def get_lt_status(self) -> 'lt.torrent_status':
+        """Get the torrent status fresh, not from cache.
+
+        This should be used when a guaranteed fresh status is needed rather than
+        `torrent.handle.status()` because it will update the cache as well.
+        """
+        self.status = self.handle.status()
+        return self.status
+
+    @property
+    def status(self) -> 'lt.torrent_status':
+        """Cached copy of the libtorrent status for this torrent.
+
+        If it has not been updated within the last five seconds, it will be
+        automatically refreshed.
+        """
+        if self._status_last_update < (time.time() - 5):
+            self.status = self.handle.status()
+        return self._status
+
+    @status.setter
+    def status(self, status: 'lt.torrent_status') -> None:
         """Updates the cached status.
 
         Args:
-            status (libtorrent.torrent_status): a libtorrent torrent status
+            status: a libtorrent torrent status
         """
-        self.status = status
+        self._status = status
+        self._status_last_update = time.time()
 
     def _create_status_funcs(self):
         """Creates the functions for getting torrent status"""
diff --git a/deluge/core/torrentmanager.py b/deluge/core/torrentmanager.py
index 753bc894c..41e1966b0 100644
--- a/deluge/core/torrentmanager.py
+++ b/deluge/core/torrentmanager.py
@@ -279,11 +279,6 @@ class TorrentManager(component.Component):
                 'Paused',
                 'Queued',
             ):
-                # If the global setting is set, but the per-torrent isn't...
-                # Just skip to the next torrent.
-                # This is so that a user can turn-off the stop at ratio option on a per-torrent basis
-                if not torrent.options['stop_at_ratio']:
-                    continue
                 if (
                     torrent.get_ratio() >= torrent.options['stop_ratio']
                     and torrent.is_finished
@@ -291,7 +286,7 @@ class TorrentManager(component.Component):
                     if torrent.options['remove_at_ratio']:
                         self.remove(torrent_id)
                         break
-                    if not torrent.handle.status().paused:
+                    if not torrent.status.paused:
                         torrent.pause()
 
     def __getitem__(self, torrent_id):
@@ -1359,10 +1354,8 @@ class TorrentManager(component.Component):
         torrent.set_tracker_status('Announce OK')
 
         # Check for peer information from the tracker, if none then send a scrape request.
-        if (
-            alert.handle.status().num_complete == -1
-            or alert.handle.status().num_incomplete == -1
-        ):
+        torrent.get_lt_status()
+        if torrent.status.num_complete == -1 or torrent.status.num_incomplete == -1:
             torrent.scrape_tracker()
 
     def on_alert_tracker_announce(self, alert):
@@ -1612,7 +1605,7 @@ class TorrentManager(component.Component):
             except RuntimeError:
                 continue
             if torrent_id in self.torrents:
-                self.torrents[torrent_id].update_status(t_status)
+                self.torrents[torrent_id].status = t_status
 
         self.handle_torrents_status_callback(self.torrents_status_requests.pop())
 
diff --git a/deluge/tests/test_torrent.py b/deluge/tests/test_torrent.py
index 6c07531dd..36adc0fde 100644
--- a/deluge/tests/test_torrent.py
+++ b/deluge/tests/test_torrent.py
@@ -3,7 +3,7 @@
 # the additional special exception to link portions of this program with the OpenSSL library.
 # See LICENSE for more details.
 #
-
+import itertools
 import os
 import time
 from base64 import b64encode
@@ -356,3 +356,20 @@ class TestTorrent(BaseTestCase):
         self.torrent = Torrent(handle, {})
         assert not self.torrent.connect_peer('127.0.0.1', 'text')
         assert self.torrent.connect_peer('127.0.0.1', '1234')
+
+    def test_status_cache(self):
+        atp = self.get_torrent_atp('test_torrent.file.torrent')
+        handle = self.session.add_torrent(atp)
+        mock_time = mock.Mock(return_value=time.time())
+        with mock.patch('time.time', mock_time):
+            torrent = Torrent(handle, {})
+            counter = itertools.count()
+            handle.status = mock.Mock(side_effect=counter.__next__)
+            first_status = torrent.get_lt_status()
+            assert first_status == 0, 'sanity check'
+            assert first_status == torrent.status, 'cached status should be used'
+            assert torrent.get_lt_status() == 1, 'status should update'
+            assert torrent.status == 1
+            # Advance time and verify cache expires and updates
+            mock_time.return_value += 10
+            assert torrent.status == 2