diff options
| -rw-r--r-- | Doc/library/fnmatch.rst | 7 | ||||
| -rw-r--r-- | Lib/fnmatch.py | 44 | ||||
| -rw-r--r-- | Lib/test/test_fnmatch.py | 23 |
3 files changed, 60 insertions, 14 deletions
diff --git a/Doc/library/fnmatch.rst b/Doc/library/fnmatch.rst index 0352b52..49073c5 100644 --- a/Doc/library/fnmatch.rst +++ b/Doc/library/fnmatch.rst @@ -84,6 +84,13 @@ patterns. <_sre.SRE_Match object at 0x...> +.. function:: purge() + + Clear the internal pattern cache. + + .. versionadded:: 3.2 + + .. seealso:: Module :mod:`glob` diff --git a/Lib/fnmatch.py b/Lib/fnmatch.py index 726fbe5..7c20e74 100644 --- a/Lib/fnmatch.py +++ b/Lib/fnmatch.py @@ -12,9 +12,19 @@ corresponding to PATTERN. (It does not compile it.) import os import posixpath import re -import functools -__all__ = ["filter", "fnmatch", "fnmatchcase", "translate"] +__all__ = ["filter", "fnmatch", "fnmatchcase", "purge", "translate"] + +_cache = {} # Maps text patterns to compiled regexen. +_cacheb = {} # Ditto for bytes patterns. +_MAXCACHE = 100 # Maximum size of caches. + + +def purge(): + """Clear the pattern cache.""" + _cache.clear() + _cacheb.clear() + def fnmatch(name, pat): """Test whether FILENAME matches PATTERN. @@ -35,21 +45,28 @@ def fnmatch(name, pat): pat = os.path.normcase(pat) return fnmatchcase(name, pat) -@functools.lru_cache(maxsize=250) -def _compile_pattern(pat, is_bytes=False): - if is_bytes: - pat_str = str(pat, 'ISO-8859-1') - res_str = translate(pat_str) - res = bytes(res_str, 'ISO-8859-1') - else: - res = translate(pat) - return re.compile(res).match + +def _compile_pattern(pat): + cache = _cacheb if isinstance(pat, bytes) else _cache + regex = cache.get(pat) + if regex is None: + if isinstance(pat, bytes): + pat_str = str(pat, 'ISO-8859-1') + res_str = translate(pat_str) + res = bytes(res_str, 'ISO-8859-1') + else: + res = translate(pat) + if len(cache) >= _MAXCACHE: + cache.clear() + cache[pat] = regex = re.compile(res) + return regex.match + def filter(names, pat): """Return the subset of the list NAMES that match PAT.""" result = [] pat = os.path.normcase(pat) - match = _compile_pattern(pat, isinstance(pat, bytes)) + match = _compile_pattern(pat) if os.path is posixpath: # normcase on posix is NOP. Optimize it away from the loop. for name in names: @@ -61,13 +78,14 @@ def filter(names, pat): result.append(name) return result + def fnmatchcase(name, pat): """Test whether FILENAME matches PATTERN, including case. This is a version of fnmatch() which doesn't case-normalize its arguments. """ - match = _compile_pattern(pat, isinstance(pat, bytes)) + match = _compile_pattern(pat) return match(name) is not None diff --git a/Lib/test/test_fnmatch.py b/Lib/test/test_fnmatch.py index 482835d..a93558c 100644 --- a/Lib/test/test_fnmatch.py +++ b/Lib/test/test_fnmatch.py @@ -3,10 +3,15 @@ from test import support import unittest -from fnmatch import fnmatch, fnmatchcase, translate, filter +from fnmatch import (fnmatch, fnmatchcase, _MAXCACHE, _cache, _cacheb, purge, + translate, filter) + class FnmatchTestCase(unittest.TestCase): + def tearDown(self): + purge() + def check_match(self, filename, pattern, should_match=1, fn=fnmatch): if should_match: self.assertTrue(fn(filename, pattern), @@ -60,6 +65,22 @@ class FnmatchTestCase(unittest.TestCase): self.check_match(b'test\xff', b'te*\xff') self.check_match(b'foo\nbar', b'foo*') + def test_cache_clearing(self): + # check that caches do not grow too large + # http://bugs.python.org/issue7846 + + # string pattern cache + for i in range(_MAXCACHE + 1): + fnmatch('foo', '?' * i) + + self.assertLessEqual(len(_cache), _MAXCACHE) + + # bytes pattern cache + for i in range(_MAXCACHE + 1): + fnmatch(b'foo', b'?' * i) + self.assertLessEqual(len(_cacheb), _MAXCACHE) + + class TranslateTestCase(unittest.TestCase): def test_translate(self): |