Mercurial > hg
changeset 40879:0c638ff69f5c
util: add method to peek item in lrucachedict
I want a function that doesn't unnecessarily update the internal state of
the cache dict after fork().
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Wed, 31 Oct 2018 22:29:05 +0900 |
parents | 2525faf4ecdb |
children | 7cda0cacbbf6 |
files | mercurial/util.py tests/test-lrucachedict.py |
diffstat | 2 files changed, 29 insertions(+), 0 deletions(-) [+] |
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--- a/mercurial/util.py Wed Oct 31 22:05:45 2018 +0900 +++ b/mercurial/util.py Wed Oct 31 22:29:05 2018 +0900 @@ -1337,6 +1337,20 @@ except KeyError: return default + def peek(self, k, default=_notset): + """Get the specified item without moving it to the head + + Unlike get(), this doesn't mutate the internal state. But be aware + that it doesn't mean peek() is thread safe. + """ + try: + node = self._cache[k] + return node.value + except KeyError: + if default is _notset: + raise + return default + def clear(self): n = self._head while n.key is not _notset:
--- a/tests/test-lrucachedict.py Wed Oct 31 22:05:45 2018 +0900 +++ b/tests/test-lrucachedict.py Wed Oct 31 22:29:05 2018 +0900 @@ -79,6 +79,21 @@ self.assertEqual(d.get('a'), 'va') self.assertEqual(list(d), ['a', 'c', 'b']) + def testpeek(self): + d = util.lrucachedict(4) + d['a'] = 'va' + d['b'] = 'vb' + d['c'] = 'vc' + + with self.assertRaises(KeyError): + d.peek('missing') + self.assertEqual(list(d), ['c', 'b', 'a']) + self.assertIsNone(d.peek('missing', None)) + self.assertEqual(list(d), ['c', 'b', 'a']) + + self.assertEqual(d.peek('a'), 'va') + self.assertEqual(list(d), ['c', 'b', 'a']) + def testcopypartial(self): d = util.lrucachedict(4) d.insert('a', 'va', cost=4)