view mercurial/match.py @ 8589:3edf133dcb5a

dirstate: skip step 3 in walk if nothing new will match

nothing will ever match on match.never
nothing new will match on match.exact (all found in step 1)
nothing new will match on match.match when
  there is no pattern and
  there is no direcory in pats

# match.py - file name matching
#
#  Copyright 2008, 2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

import util, re

class match(object):
    def __init__(self, root, cwd, patterns, include=[], exclude=[],
                 default='glob', exact=False):
        """build an object to match a set of file patterns

        arguments:
        root - the canonical root of the tree you're matching against
        cwd - the current working directory, if relevant
        patterns - patterns to find
        include - patterns to include
        exclude - patterns to exclude
        default - if a pattern in names has no explicit type, assume this one
        exact - patterns are actually literals

        a pattern is one of:
        'glob:<glob>' - a glob relative to cwd
        're:<regexp>' - a regular expression
        'path:<path>' - a path relative to canonroot
        'relglob:<glob>' - an unrooted glob (*.c matches C files in all dirs)
        'relpath:<path>' - a path relative to cwd
        'relre:<regexp>' - a regexp that needn't match the start of a name
        '<something>' - a pattern of the specified default type
        """

        self._root = root
        self._cwd = cwd
        self._files = []
        self._anypats = bool(include or exclude)

        if include:
            im = _buildmatch(_normalize(include, 'glob', root, cwd), '(?:/|$)')
        if exclude:
            em = _buildmatch(_normalize(exclude, 'glob', root, cwd), '(?:/|$)')
        if exact:
            self._files = patterns
            pm = self.exact
        elif patterns:
            pats = _normalize(patterns, default, root, cwd)
            self._files = _roots(pats)
            self._anypats = self._anypats or _anypats(pats)
            pm = _buildmatch(pats, '$')

        if patterns or exact:
            if include:
                if exclude:
                    m = lambda f: im(f) and not em(f) and pm(f)
                else:
                    m = lambda f: im(f) and pm(f)
            else:
                if exclude:
                    m = lambda f: not em(f) and pm(f)
                else:
                    m = pm
        else:
            if include:
                if exclude:
                    m = lambda f: im(f) and not em(f)
                else:
                    m = im
            else:
                if exclude:
                    m = lambda f: not em(f)
                else:
                    m = lambda f: True

        self.matchfn = m
        self._fmap = set(self._files)

    def __call__(self, fn):
        return self.matchfn(fn)
    def __iter__(self):
        for f in self._files:
            yield f
    def bad(self, f, msg):
        return True
    def dir(self, f):
        pass
    def missing(self, f):
        pass
    def exact(self, f):
        return f in self._fmap
    def rel(self, f):
        return util.pathto(self._root, self._cwd, f)
    def files(self):
        return self._files
    def anypats(self):
        return self._anypats

class exact(match):
    def __init__(self, root, cwd, files):
        match.__init__(self, root, cwd, files, exact = True)

class always(match):
    def __init__(self, root, cwd):
        match.__init__(self, root, cwd, [])

class never(match):
    def __init__(self, root, cwd):
        match.__init__(self, root, cwd, [], exact = True)

def patkind(pat):
    return _patsplit(pat, None)[0]

def _patsplit(pat, default):
    """Split a string into an optional pattern kind prefix and the
    actual pattern."""
    if ':' in pat:
        pat, val = pat.split(':', 1)
        if pat in ('re', 'glob', 'path', 'relglob', 'relpath', 'relre'):
            return pat, val
    return default, pat

def _globre(pat):
    "convert a glob pattern into a regexp"
    i, n = 0, len(pat)
    res = ''
    group = 0
    escape = re.escape
    def peek(): return i < n and pat[i]
    while i < n:
        c = pat[i]
        i = i+1
        if c not in '*?[{},\\':
            res += escape(c)
        elif c == '*':
            if peek() == '*':
                i += 1
                res += '.*'
            else:
                res += '[^/]*'
        elif c == '?':
            res += '.'
        elif c == '[':
            j = i
            if j < n and pat[j] in '!]':
                j += 1
            while j < n and pat[j] != ']':
                j += 1
            if j >= n:
                res += '\\['
            else:
                stuff = pat[i:j].replace('\\','\\\\')
                i = j + 1
                if stuff[0] == '!':
                    stuff = '^' + stuff[1:]
                elif stuff[0] == '^':
                    stuff = '\\' + stuff
                res = '%s[%s]' % (res, stuff)
        elif c == '{':
            group += 1
            res += '(?:'
        elif c == '}' and group:
            res += ')'
            group -= 1
        elif c == ',' and group:
            res += '|'
        elif c == '\\':
            p = peek()
            if p:
                i += 1
                res += escape(p)
            else:
                res += escape(c)
        else:
            res += escape(c)
    return res

def _regex(kind, name, tail):
    '''convert a pattern into a regular expression'''
    if not name:
        return ''
    if kind == 're':
        return name
    elif kind == 'path':
        return '^' + re.escape(name) + '(?:/|$)'
    elif kind == 'relglob':
        return '(?:|.*/)' + _globre(name) + tail
    elif kind == 'relpath':
        return re.escape(name) + '(?:/|$)'
    elif kind == 'relre':
        if name.startswith('^'):
            return name
        return '.*' + name
    return _globre(name) + tail

def _buildmatch(pats, tail):
    """build a matching function from a set of patterns"""
    try:
        pat = '(?:%s)' % '|'.join([_regex(k, p, tail) for (k, p) in pats])
        if len(pat) > 20000:
            raise OverflowError()
        return re.compile(pat).match
    except OverflowError:
        # We're using a Python with a tiny regex engine and we
        # made it explode, so we'll divide the pattern list in two
        # until it works
        l = len(pats)
        if l < 2:
            raise
        a, b = _buildmatch(pats[:l//2], tail), _buildmatch(pats[l//2:], tail)
        return lambda s: a(s) or b(s)
    except re.error:
        for k, p in pats:
            try:
                re.compile('(?:%s)' % _regex(k, p, tail))
            except re.error:
                raise util.Abort("invalid pattern (%s): %s" % (k, p))
        raise util.Abort("invalid pattern")

def _normalize(names, default, root, cwd):
    pats = []
    for kind, name in [_patsplit(p, default) for p in names]:
        if kind in ('glob', 'relpath'):
            name = util.canonpath(root, cwd, name)
        elif kind in ('relglob', 'path'):
            name = util.normpath(name)

        pats.append((kind, name))
    return pats

def _roots(patterns):
    r = []
    for kind, name in patterns:
        if kind == 'glob': # find the non-glob prefix
            root = []
            for p in name.split('/'):
                if '[' in p or '{' in p or '*' in p or '?' in p:
                    break
                root.append(p)
            r.append('/'.join(root) or '.')
        elif kind in ('relpath', 'path'):
            r.append(name or '.')
        elif kind == 'relglob':
            r.append('.')
    return r

def _anypats(patterns):
    for kind, name in patterns:
        if kind in ('glob', 're', 'relglob', 'relre'):
            return True