view mercurial/minifileset.py @ 40424:7caf632e30c3

filecache: unimplement __set__() and __delete__() (API)

Implementing __set__() implies that the descriptor can't be overridden by
obj.__dict__, which means any property access involves slow function call.

  "Data descriptors with __set__() and __get__() defined always override
  a redefinition in an instance dictionary. In contrast, non-data descriptors
  can be overridden by instances."

  https://docs.python.org/2.7/reference/datamodel.html#invoking-descriptors

This patch basically backs out 236bb604dc39, "scmutil: update cached copy
when filecached attribute is assigned (issue3263)." The problem described
in issue3263 (which is #3264 in Bugzilla) should no longer happen since
repo._bookmarkcurrent has been moved to repo._bookmarks.active. We still
have a risk of introducing similar bugs, but I think that's the cost we
have to pay.

  $ hg perfrevset 'branch(tip)' -R mercurial
  (orig) wall 0.139511 comb 0.140000 user 0.140000 sys 0.000000 (best of 66)
  (prev) wall 0.114195 comb 0.110000 user 0.110000 sys 0.000000 (best of 81)
  (this) wall 0.099038 comb 0.110000 user 0.100000 sys 0.010000 (best of 93)

# minifileset.py - a simple language to select files
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from .i18n import _
from . import (
    error,
    fileset,
    filesetlang,
    pycompat,
)

def _sizep(x):
    # i18n: "size" is a keyword
    expr = filesetlang.getstring(x, _("size requires an expression"))
    return fileset.sizematcher(expr)

def _compile(tree):
    if not tree:
        raise error.ParseError(_("missing argument"))
    op = tree[0]
    if op == 'withstatus':
        return _compile(tree[1])
    elif op in {'symbol', 'string', 'kindpat'}:
        name = filesetlang.getpattern(tree, {'path'}, _('invalid file pattern'))
        if name.startswith('**'): # file extension test, ex. "**.tar.gz"
            ext = name[2:]
            for c in pycompat.bytestr(ext):
                if c in '*{}[]?/\\':
                    raise error.ParseError(_('reserved character: %s') % c)
            return lambda n, s: n.endswith(ext)
        elif name.startswith('path:'): # directory or full path test
            p = name[5:] # prefix
            pl = len(p)
            f = lambda n, s: n.startswith(p) and (len(n) == pl
                                                  or n[pl:pl + 1] == '/')
            return f
        raise error.ParseError(_("unsupported file pattern: %s") % name,
                               hint=_('paths must be prefixed with "path:"'))
    elif op in {'or', 'patterns'}:
        funcs = [_compile(x) for x in tree[1:]]
        return lambda n, s: any(f(n, s) for f in funcs)
    elif op == 'and':
        func1 = _compile(tree[1])
        func2 = _compile(tree[2])
        return lambda n, s: func1(n, s) and func2(n, s)
    elif op == 'not':
        return lambda n, s: not _compile(tree[1])(n, s)
    elif op == 'func':
        symbols = {
            'all': lambda n, s: True,
            'none': lambda n, s: False,
            'size': lambda n, s: _sizep(tree[2])(s),
        }

        name = filesetlang.getsymbol(tree[1])
        if name in symbols:
            return symbols[name]

        raise error.UnknownIdentifier(name, symbols.keys())
    elif op == 'minus':     # equivalent to 'x and not y'
        func1 = _compile(tree[1])
        func2 = _compile(tree[2])
        return lambda n, s: func1(n, s) and not func2(n, s)
    elif op == 'list':
        raise error.ParseError(_("can't use a list in this context"),
                               hint=_('see \'hg help "filesets.x or y"\''))
    raise error.ProgrammingError('illegal tree: %r' % (tree,))

def compile(text):
    """generate a function (path, size) -> bool from filter specification.

    "text" could contain the operators defined by the fileset language for
    common logic operations, and parenthesis for grouping.  The supported path
    tests are '**.extname' for file extension test, and '"path:dir/subdir"'
    for prefix test.  The ``size()`` predicate is borrowed from filesets to test
    file size.  The predicates ``all()`` and ``none()`` are also supported.

    '(**.php & size(">10MB")) | **.zip | (path:bin & !path:bin/README)' for
    example, will catch all php files whose size is greater than 10 MB, all
    files whose name ends with ".zip", and all files under "bin" in the repo
    root except for "bin/README".
    """
    tree = filesetlang.parse(text)
    tree = filesetlang.analyze(tree)
    tree = filesetlang.optimize(tree)
    return _compile(tree)