From 8d2f3c36caf9ecdee1176314b18388aef6e7f2c2 Mon Sep 17 00:00:00 2001 From: "J. Nick Koston" Date: Thu, 13 Jul 2023 09:18:53 -1000 Subject: gh-106664: selectors: add get() method to _SelectorMapping (#106665) It can be used to avoid raising and catching KeyError twice via __getitem__. Co-authored-by: Inada Naoki --- Lib/selectors.py | 14 +++++++++----- Lib/test/test_selectors.py | 6 ++++++ .../Library/2023-07-12-03-04-45.gh-issue-106664.ZeUG78.rst | 1 + 3 files changed, 16 insertions(+), 5 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2023-07-12-03-04-45.gh-issue-106664.ZeUG78.rst diff --git a/Lib/selectors.py b/Lib/selectors.py index af6a4f9..dfcc125 100644 --- a/Lib/selectors.py +++ b/Lib/selectors.py @@ -66,12 +66,16 @@ class _SelectorMapping(Mapping): def __len__(self): return len(self._selector._fd_to_key) + def get(self, fileobj, default=None): + fd = self._selector._fileobj_lookup(fileobj) + return self._selector._fd_to_key.get(fd, default) + def __getitem__(self, fileobj): - try: - fd = self._selector._fileobj_lookup(fileobj) - return self._selector._fd_to_key[fd] - except KeyError: - raise KeyError("{!r} is not registered".format(fileobj)) from None + fd = self._selector._fileobj_lookup(fileobj) + key = self._selector._fd_to_key.get(fd) + if key is None: + raise KeyError("{!r} is not registered".format(fileobj)) + return key def __iter__(self): return iter(self._selector._fd_to_key) diff --git a/Lib/test/test_selectors.py b/Lib/test/test_selectors.py index c2db88c..4545cba 100644 --- a/Lib/test/test_selectors.py +++ b/Lib/test/test_selectors.py @@ -223,6 +223,8 @@ class BaseSelectorTestCase: self.assertRaises(RuntimeError, s.get_key, wr) self.assertRaises(KeyError, mapping.__getitem__, rd) self.assertRaises(KeyError, mapping.__getitem__, wr) + self.assertEqual(mapping.get(rd), None) + self.assertEqual(mapping.get(wr), None) def test_get_key(self): s = self.SELECTOR() @@ -241,13 +243,17 @@ class BaseSelectorTestCase: self.addCleanup(s.close) rd, wr = self.make_socketpair() + sentinel = object() keys = s.get_map() self.assertFalse(keys) self.assertEqual(len(keys), 0) self.assertEqual(list(keys), []) + self.assertEqual(keys.get(rd), None) + self.assertEqual(keys.get(rd, sentinel), sentinel) key = s.register(rd, selectors.EVENT_READ, "data") self.assertIn(rd, keys) + self.assertEqual(key, keys.get(rd)) self.assertEqual(key, keys[rd]) self.assertEqual(len(keys), 1) self.assertEqual(list(keys), [rd.fileno()]) diff --git a/Misc/NEWS.d/next/Library/2023-07-12-03-04-45.gh-issue-106664.ZeUG78.rst b/Misc/NEWS.d/next/Library/2023-07-12-03-04-45.gh-issue-106664.ZeUG78.rst new file mode 100644 index 0000000..c278cad --- /dev/null +++ b/Misc/NEWS.d/next/Library/2023-07-12-03-04-45.gh-issue-106664.ZeUG78.rst @@ -0,0 +1 @@ +:mod:`selectors`: Add ``_SelectorMapping.get()`` method and optimize ``_SelectorMapping.__getitem__()``. -- cgit v0.12