mercurial/match.py

revset-_descendant: rework the whole sorting and combining logic

We use the & operator to combine with subset (since this is more likely to be
optimised than filter) and we enforce the sorting of the result. Without this
enforced sorting, we may result in a different iteration order than the set
_descendent was computed from.

This reverts a bad `test-glog.t` change from 69402eb72115.

Another side effect is that `test-mq.t` shows `qparent::` including `-1` if
`qparent is -1`. This sound like a positive change.

This has good and bad impacts on the benchmarks, here is a good ones:

revset: 0::
before) wall 0.045489 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
after)  wall 0.034330 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)

revset: roots((0::) - (0::tip))
before)  wall 0.134090 comb 0.140000 user 0.140000 sys 0.000000 (best of 63)
after) wall 0.128346 comb 0.130000 user 0.130000 sys 0.000000 (best of 69)

revset: ::p1(p1(tip))::
before) wall 0.143892 comb 0.140000 user 0.140000 sys 0.000000 (best of 55)
after)  wall 0.124502 comb 0.130000 user 0.130000 sys 0.000000 (best of 65)

revset: roots((0:tip)::)
before) wall 0.204966 comb 0.200000 user 0.200000 sys 0.000000 (best of 43)
after) wall 0.184455 comb 0.180000 user 0.180000 sys 0.000000 (best of 47)

Here is a bad one:

revset: (20000::) - (20000)
before) wall 0.009592 comb 0.010000 user 0.010000 sys 0.000000 (best of 222)
after)  wall 0.029837 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)

# match.py - filename 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 or any later version.

import re
import util, pathutil
from i18n import _

def _rematcher(regex):
    '''compile the regexp with the best available regexp engine and return a
    matcher function'''
    m = util.re.compile(regex)
    try:
        # slightly faster, provided by facebook's re2 bindings
        return m.test_match
    except AttributeError:
        return m.match

def _expandsets(kindpats, ctx):
    '''Returns the kindpats list with the 'set' patterns expanded.'''
    fset = set()
    other = []

    for kind, pat in kindpats:
        if kind == 'set':
            if not ctx:
                raise util.Abort("fileset expression with no context")
            s = ctx.getfileset(pat)
            fset.update(s)
            continue
        other.append((kind, pat))
    return fset, other

class match(object):
    def __init__(self, root, cwd, patterns, include=[], exclude=[],
                 default='glob', exact=False, auditor=None, ctx=None):
        """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 (unless they are excluded)
        exclude - patterns to exclude (even if they are included)
        default - if a pattern in patterns has no explicit type, assume this one
        exact - patterns are actually filenames (include/exclude still apply)

        a pattern is one of:
        'glob:<glob>' - a glob relative to cwd
        're:<regexp>' - a regular expression
        'path:<path>' - a path relative to repository root
        '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
        'set:<fileset>' - a fileset expression
        '<something>' - a pattern of the specified default type
        """

        self._root = root
        self._cwd = cwd
        self._files = [] # exact files and roots of patterns
        self._anypats = bool(include or exclude)
        self._ctx = ctx
        self._always = False

        matchfns = []
        if include:
            kindpats = _normalize(include, 'glob', root, cwd, auditor)
            self.includepat, im = _buildmatch(ctx, kindpats, '(?:/|$)')
            matchfns.append(im)
        if exclude:
            kindpats = _normalize(exclude, 'glob', root, cwd, auditor)
            self.excludepat, em = _buildmatch(ctx, kindpats, '(?:/|$)')
            matchfns.append(lambda f: not em(f))
        if exact:
            if isinstance(patterns, list):
                self._files = patterns
            else:
                self._files = list(patterns)
            matchfns.append(self.exact)
        elif patterns:
            kindpats = _normalize(patterns, default, root, cwd, auditor)
            self._files = _roots(kindpats)
            self._anypats = self._anypats or _anypats(kindpats)
            self.patternspat, pm = _buildmatch(ctx, kindpats, '$')
            matchfns.append(pm)

        if not matchfns:
            m = util.always
            self._always = True
        elif len(matchfns) == 1:
            m = matchfns[0]
        else:
            def m(f):
                for matchfn in matchfns:
                    if not matchfn(f):
                        return False
                return 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

    # Callbacks related to how the matcher is used by dirstate.walk.
    # Subscribers to these events must monkeypatch the matcher object.
    def bad(self, f, msg):
        '''Callback from dirstate.walk for each explicit file that can't be
        found/accessed, with an error message.'''
        pass

    # If an explicitdir is set, it will be called when an explicitly listed
    # directory is visited.
    explicitdir = None

    # If an traversedir is set, it will be called when a directory discovered
    # by recursive traversal is visited.
    traversedir = None

    def rel(self, f):
        '''Convert repo path back to path that is relative to cwd of matcher.'''
        return util.pathto(self._root, self._cwd, f)

    def files(self):
        '''Explicitly listed files or patterns or roots:
        if no patterns or .always(): empty list,
        if exact: list exact files,
        if not .anypats(): list all files and dirs,
        else: optimal roots'''
        return self._files

    def exact(self, f):
        '''Returns True if f is in .files().'''
        return f in self._fmap

    def anypats(self):
        '''Matcher uses patterns or include/exclude.'''
        return self._anypats

    def always(self):
        '''Matcher will match everything and .files() will be empty
        - optimization might be possible and necessary.'''
        return self._always

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 narrowmatcher(match):
    """Adapt a matcher to work on a subdirectory only.

    The paths are remapped to remove/insert the path as needed:

    >>> m1 = match('root', '', ['a.txt', 'sub/b.txt'])
    >>> m2 = narrowmatcher('sub', m1)
    >>> bool(m2('a.txt'))
    False
    >>> bool(m2('b.txt'))
    True
    >>> bool(m2.matchfn('a.txt'))
    False
    >>> bool(m2.matchfn('b.txt'))
    True
    >>> m2.files()
    ['b.txt']
    >>> m2.exact('b.txt')
    True
    >>> m2.rel('b.txt')
    'b.txt'
    >>> def bad(f, msg):
    ...     print "%s: %s" % (f, msg)
    >>> m1.bad = bad
    >>> m2.bad('x.txt', 'No such file')
    sub/x.txt: No such file
    """

    def __init__(self, path, matcher):
        self._root = matcher._root
        self._cwd = matcher._cwd
        self._path = path
        self._matcher = matcher
        self._always = matcher._always

        self._files = [f[len(path) + 1:] for f in matcher._files
                       if f.startswith(path + "/")]
        self._anypats = matcher._anypats
        self.matchfn = lambda fn: matcher.matchfn(self._path + "/" + fn)
        self._fmap = set(self._files)

    def bad(self, f, msg):
        self._matcher.bad(self._path + "/" + f, msg)

def patkind(pattern, default=None):
    '''If pattern is 'kind:pat' with a known kind, return kind.'''
    return _patsplit(pattern, default)[0]

def _patsplit(pattern, default):
    """Split a string into the optional pattern kind prefix and the actual
    pattern."""
    if ':' in pattern:
        kind, pat = pattern.split(':', 1)
        if kind in ('re', 'glob', 'path', 'relglob', 'relpath', 'relre',
                    'listfile', 'listfile0', 'set'):
            return kind, pat
    return default, pattern

def _globre(pat):
    r'''Convert an extended glob string to a regexp string.

    >>> print _globre(r'?')
    .
    >>> print _globre(r'*')
    [^/]*
    >>> print _globre(r'**')
    .*
    >>> print _globre(r'**/a')
    (?:.*/)?a
    >>> print _globre(r'a/**/b')
    a\/(?:.*/)?b
    >>> print _globre(r'[a*?!^][^b][!c]')
    [a*?!^][\^b][^c]
    >>> print _globre(r'{a,b}')
    (?:a|b)
    >>> print _globre(r'.\*\?')
    \.\*\?
    '''
    i, n = 0, len(pat)
    res = ''
    group = 0
    escape = util.re.escape
    def peek():
        return i < n and pat[i]
    while i < n:
        c = pat[i]
        i += 1
        if c not in '*?[{},\\':
            res += escape(c)
        elif c == '*':
            if peek() == '*':
                i += 1
                if peek() == '/':
                    i += 1
                    res += '(?:.*/)?'
                else:
                    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, pat, globsuffix):
    '''Convert a (normalized) pattern of any kind into a regular expression.
    globsuffix is appended to the regexp of globs.'''
    if not pat:
        return ''
    if kind == 're':
        return pat
    if kind == 'path':
        return '^' + util.re.escape(pat) + '(?:/|$)'
    if kind == 'relglob':
        return '(?:|.*/)' + _globre(pat) + globsuffix
    if kind == 'relpath':
        return util.re.escape(pat) + '(?:/|$)'
    if kind == 'relre':
        if pat.startswith('^'):
            return pat
        return '.*' + pat
    return _globre(pat) + globsuffix

def _buildmatch(ctx, kindpats, globsuffix):
    '''Return regexp string and a matcher function for kindpats.
    globsuffix is appended to the regexp of globs.'''
    fset, kindpats = _expandsets(kindpats, ctx)
    if not kindpats:
        return "", fset.__contains__

    regex, mf = _buildregexmatch(kindpats, globsuffix)
    if fset:
        return regex, lambda f: f in fset or mf(f)
    return regex, mf

def _buildregexmatch(kindpats, globsuffix):
    """Build a match function from a list of kinds and kindpats,
    return regexp string and a matcher function."""
    try:
        regex = '(?:%s)' % '|'.join([_regex(k, p, globsuffix)
                                     for (k, p) in kindpats])
        if len(regex) > 20000:
            raise OverflowError
        return regex, _rematcher(regex)
    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(kindpats)
        if l < 2:
            raise
        regexa, a = _buildregexmatch(kindpats[:l//2], globsuffix)
        regexb, b = _buildregexmatch(kindpats[l//2:], globsuffix)
        return regex, lambda s: a(s) or b(s)
    except re.error:
        for k, p in kindpats:
            try:
                _rematcher('(?:%s)' % _regex(k, p, globsuffix))
            except re.error:
                raise util.Abort(_("invalid pattern (%s): %s") % (k, p))
        raise util.Abort(_("invalid pattern"))

def _normalize(patterns, default, root, cwd, auditor):
    '''Convert 'kind:pat' from the patterns list to tuples with kind and
    normalized and rooted patterns and with listfiles expanded.'''
    kindpats = []
    for kind, pat in [_patsplit(p, default) for p in patterns]:
        if kind in ('glob', 'relpath'):
            pat = pathutil.canonpath(root, cwd, pat, auditor)
        elif kind in ('relglob', 'path'):
            pat = util.normpath(pat)
        elif kind in ('listfile', 'listfile0'):
            try:
                files = util.readfile(pat)
                if kind == 'listfile0':
                    files = files.split('\0')
                else:
                    files = files.splitlines()
                files = [f for f in files if f]
            except EnvironmentError:
                raise util.Abort(_("unable to read file list (%s)") % pat)
            kindpats += _normalize(files, default, root, cwd, auditor)
            continue
        # else: re or relre - which cannot be normalized
        kindpats.append((kind, pat))
    return kindpats

def _roots(kindpats):
    '''return roots and exact explicitly listed files from patterns

    >>> _roots([('glob', 'g/*'), ('glob', 'g'), ('glob', 'g*')])
    ['g', 'g', '.']
    >>> _roots([('relpath', 'r'), ('path', 'p/p'), ('path', '')])
    ['r', 'p/p', '.']
    >>> _roots([('relglob', 'rg*'), ('re', 're/'), ('relre', 'rr')])
    ['.', '.', '.']
    '''
    r = []
    for kind, pat in kindpats:
        if kind == 'glob': # find the non-glob prefix
            root = []
            for p in pat.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(pat or '.')
        else: # relglob, re, relre
            r.append('.')
    return r

def _anypats(kindpats):
    for kind, pat in kindpats:
        if kind in ('glob', 're', 'relglob', 'relre', 'set'):
            return True