1
# Copyright (C) 2006 Canonical Ltd
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
# GNU General Public License for more details.
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
15
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17
"""Tools for converting globs to regular expressions.
19
This module provides functions for converting shell-like globs to regular
26
from bzrlib.trace import (
32
class Replacer(object):
33
"""Do a multiple-pattern substitution.
35
The patterns and substitutions are combined into one, so the result of
36
one replacement is never substituted again. Add the patterns and
37
replacements via the add method and then call the object. The patterns
38
must not contain capturing groups.
41
_expand = re.compile(ur'\\&')
43
def __init__(self, source=None):
46
self._pats = list(source._pats)
47
self._funs = list(source._funs)
52
def add(self, pat, fun):
53
r"""Add a pattern and replacement.
55
The pattern must not contain capturing groups.
56
The replacement might be either a string template in which \& will be
57
replaced with the match, or a function that will get the matching text
58
as argument. It does not get match object, because capturing is
62
self._pats.append(pat)
63
self._funs.append(fun)
65
def add_replacer(self, replacer):
66
r"""Add all patterns from another replacer.
68
All patterns and replacements from replacer are appended to the ones
72
self._pats.extend(replacer._pats)
73
self._funs.extend(replacer._funs)
75
def __call__(self, text):
77
self._pat = re.compile(
78
u'|'.join([u'(%s)' % p for p in self._pats]),
80
return self._pat.sub(self._do_sub, text)
83
fun = self._funs[m.lastindex - 1]
84
if hasattr(fun, '__call__'):
85
return fun(m.group(0))
87
return self._expand.sub(m.group(0), fun)
90
_sub_named = Replacer()
91
_sub_named.add(ur'\[:digit:\]', ur'\d')
92
_sub_named.add(ur'\[:space:\]', ur'\s')
93
_sub_named.add(ur'\[:alnum:\]', ur'\w')
94
_sub_named.add(ur'\[:ascii:\]', ur'\0-\x7f')
95
_sub_named.add(ur'\[:blank:\]', ur' \t')
96
_sub_named.add(ur'\[:cntrl:\]', ur'\0-\x1f\x7f-\x9f')
100
if m[1] in (u'!', u'^'):
101
return u'[^' + _sub_named(m[2:-1]) + u']'
102
return u'[' + _sub_named(m[1:-1]) + u']'
105
def _invalid_regex(repl):
107
warning(u"'%s' not allowed withing regexp. Replacing with '%s'" %
114
_sub_re.add(u'^RE:', u'')
115
_sub_re.add(u'\((?!\?)', u'(?:')
116
_sub_re.add(u'\(\?P<.*>', _invalid_regex(u'(?:'))
117
_sub_re.add(u'\(\?P=[^)]*\)', _invalid_regex(u''))
120
_sub_fullpath = Replacer()
121
_sub_fullpath.add(ur'^RE:.*', _sub_re) # RE:<anything> is a regex
122
_sub_fullpath.add(ur'\[\^?\]?(?:[^][]|\[:[^]]+:\])+\]', _sub_group) # char group
123
_sub_fullpath.add(ur'(?:(?<=/)|^)(?:\.?/)+', u'') # canonicalize path
124
_sub_fullpath.add(ur'\\.', ur'\&') # keep anything backslashed
125
_sub_fullpath.add(ur'[(){}|^$+.]', ur'\\&') # escape specials
126
_sub_fullpath.add(ur'(?:(?<=/)|^)\*\*+/', ur'(?:.*/)?') # **/ after ^ or /
127
_sub_fullpath.add(ur'\*+', ur'[^/]*') # * elsewhere
128
_sub_fullpath.add(ur'\?', ur'[^/]') # ? everywhere
131
_sub_basename = Replacer()
132
_sub_basename.add(ur'\[\^?\]?(?:[^][]|\[:[^]]+:\])+\]', _sub_group) # char group
133
_sub_basename.add(ur'\\.', ur'\&') # keep anything backslashed
134
_sub_basename.add(ur'[(){}|^$+.]', ur'\\&') # escape specials
135
_sub_basename.add(ur'\*+', ur'.*') # * everywhere
136
_sub_basename.add(ur'\?', ur'.') # ? everywhere
139
def _sub_extension(pattern):
140
return _sub_basename(pattern[2:])
143
class Globster(object):
144
"""A simple wrapper for a set of glob patterns.
146
Provides the capability to search the patterns to find a match for
147
a given filename (including the full path).
149
Patterns are translated to regular expressions to expidite matching.
151
The regular expressions for multiple patterns are aggregated into
152
a super-regex containing groups of up to 99 patterns.
153
The 99 limitation is due to the grouping limit of the Python re module.
154
The resulting super-regex and associated patterns are stored as a list of
155
(regex,[patterns]) in _regex_patterns.
157
For performance reasons the patterns are categorised as extension patterns
158
(those that match against a file extension), basename patterns
159
(those that match against the basename of the filename),
160
and fullpath patterns (those that match against the full path).
161
The translations used for extensions and basenames are relatively simpler
162
and therefore faster to perform than the fullpath patterns.
164
Also, the extension patterns are more likely to find a match and
165
so are matched first, then the basename patterns, then the fullpath
168
def __init__(self, patterns):
169
self._regex_patterns = []
174
if pat.startswith(u'RE:') or u'/' in pat:
175
path_patterns.append(pat)
176
elif pat.startswith(u'*.'):
177
ext_patterns.append(pat)
179
base_patterns.append(pat)
180
self._add_patterns(ext_patterns,_sub_extension,
181
prefix=r'(?:.*/)?(?!.*/)(?:.*\.)')
182
self._add_patterns(base_patterns,_sub_basename,
183
prefix=r'(?:.*/)?(?!.*/)')
184
self._add_patterns(path_patterns,_sub_fullpath)
186
def _add_patterns(self, patterns, translator, prefix=''):
188
grouped_rules = ['(%s)' % translator(pat) for pat in patterns[:99]]
189
joined_rule = '%s(?:%s)$' % (prefix, '|'.join(grouped_rules))
190
self._regex_patterns.append((re.compile(joined_rule, re.UNICODE),
192
patterns = patterns[99:]
194
def match(self, filename):
195
"""Searches for a pattern that matches the given filename.
197
:return A matching pattern or None if there is no matching pattern.
199
for regex, patterns in self._regex_patterns:
200
match = regex.match(filename)
202
return patterns[match.lastindex -1]