switch utils.deadline to a context manager

modules/sed.py

@@ -55,10 +55,10 @@ class Module(ModuleManager.BaseModule):
             for_user = event["user"].nickname if self._closest_setting(event,
                 "sed-sender-only", False) else None
 
-            def _find():
-                return event["target"].buffer.find(pattern, from_self=False,
+            with utils.deadline():
+                match = event["target"].buffer.find(pattern, from_self=False,
                     for_user=for_user, not_pattern=REGEX_SED)
-            match = utils.deadline(_find)
+
             if match:
                 new_message = re.sub(pattern, replace, match.line.message,
                     count)

src/utils/__init__.py

@@ -1,4 +1,5 @@
-import datetime, decimal, enum, io, ipaddress, re, signal, threading, typing
+import contextlib, datetime, decimal, enum, io, ipaddress, re, signal
+import threading, typing
 from src.utils import cli, consts, irc, http, parse, security
 
 class Direction(enum.Enum):
@@ -348,11 +349,13 @@ class DeadlineExceededException(Exception):
 def _raise_deadline():
     raise DeadlineExceededException()
 
-def deadline(f: typing.Callable[[], typing.Any], seconds: int=10) -> typing.Any:
-    signal.signal(signal.SIGALRM, lambda _1, _2: _raise_deadline())
+@contextlib.contextmanager
+def deadline(seconds: int=10):
+    old_handler = signal.signal(signal.SIGALRM,
+        lambda _1, _2: _raise_deadline())
     signal.alarm(seconds)
 
     try:
-        return f()
+        yield
     finally:
-        signal.signal(signal.SIGALRM, signal.SIG_IGN)
+        signal.signal(signal.SIGALRM, old_handler)