fix: free unused journal.Reader instances (#158)

I'm a bit dumb and forgot to add code that frees journal.Reader instances from memory.

Co-authored-by: nhnn <nhnn@disroot.org>
Co-authored-by: Inex Code <inex.code@selfprivacy.org>
Reviewed-on: https://git.selfprivacy.org/SelfPrivacy/selfprivacy-rest-api/pulls/158
Reviewed-by: Inex Code <inex.code@selfprivacy.org>
Co-authored-by: nhnn <nhnn@noreply.git.selfprivacy.org>
Co-committed-by: nhnn <nhnn@noreply.git.selfprivacy.org>

selfprivacy_api/graphql/subscriptions/logs.py

@@ -21,11 +21,17 @@ async def log_stream() -> AsyncGenerator[LogEntry, None]:
 
     asyncio.get_event_loop().add_reader(j, lambda: asyncio.ensure_future(callback()))
 
-    while True:
-        entry = await queue.get()
-        try:
-            yield LogEntry(entry)
-        except Exception:
-            asyncio.get_event_loop().remove_reader(j)
-            return
-        queue.task_done()
+    try:
+        while True:
+            entry = await queue.get()
+            try:
+                yield LogEntry(entry)
+            except Exception:
+                asyncio.get_event_loop().remove_reader(j)
+                j.close()
+                return
+            queue.task_done()
+    except asyncio.CancelledError:
+        asyncio.get_event_loop().remove_reader(j)
+        j.close()
+        return

selfprivacy_api/utils/systemd_journal.py

@@ -42,6 +42,8 @@ def get_paginated_logs(
         events = get_events_from_journal(j, limit, lambda j: j.get_previous())
         events.reverse()
 
+        j.close()
+
         return events
     elif up_cursor is None and down_cursor is not None:
         j.seek_cursor(down_cursor)
@@ -50,6 +52,8 @@ def get_paginated_logs(
         events = get_events_from_journal(j, limit, lambda j: j.get_previous())
         events.reverse()
 
+        j.close()
+
         return events
     elif up_cursor is not None and down_cursor is None:
         j.seek_cursor(up_cursor)
@@ -57,8 +61,12 @@ def get_paginated_logs(
 
         events = get_events_from_journal(j, limit, lambda j: j.get_next())
 
+        j.close()
+
         return events
     else:
+        j.close()
+
         raise NotImplementedError(
             "Pagination by both up_cursor and down_cursor is not implemented"
         )