~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2008, 2009, 2010 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Rule-based definition of preferences for selected files in selected branches.

See ``bzr help rules`` for details.

"""

from bzrlib import (

    config,

    cmdline,

    errors,

    globbing,

    osutils,

    )

from bzrlib.util.configobj import configobj

# Name of the file holding rules in a tree

RULES_TREE_FILENAME = ".bzrrules"

# Namespace prefix for per file preferences

FILE_PREFS_PREFIX = 'name '

FILE_PREFS_PREFIX_LEN = len(FILE_PREFS_PREFIX)

# The object providing default rules

_per_user_searcher = None

class _RulesSearcher(object):

    """An object that provides rule-based preferences."""

    def get_items(self, path):

        """Return the preferences for a path as name,value tuples.

        :param path: tree relative path

        :return: () if no rule matched, otherwise a sequence of name,value

          tuples.

        """

        raise NotImplementedError(self.get_items)

    def get_selected_items(self, path, names):

        """Return selected preferences for a path as name,value tuples.

        :param path: tree relative path

        :param names: the list of preferences to lookup

        :return: () if no rule matched, otherwise a sequence of name,value

          tuples. The sequence is the same length as names,

          tuple order matches the order in names, and

          undefined preferences are given the value None.

        """

        raise NotImplementedError(self.get_selected_items)

    def get_single_value(self, path, preference_name):

        """Get a single preference for a single file.

        :returns: The string preference value, or None.

        """

        for key, value in self.get_selected_items(path, [preference_name]):

            return value

        return None

class _IniBasedRulesSearcher(_RulesSearcher):

    def __init__(self, inifile):

        """Construct a _RulesSearcher based on an ini file.

        The content will be decoded as utf-8.

        :param inifile: the name of the file or a sequence of lines.

        """

        self._cfg = configobj.ConfigObj(inifile, encoding='utf-8')

        sections = self._cfg.keys()

        patterns = []

        self.pattern_to_section = {}

        for s in sections:

            if s.startswith(FILE_PREFS_PREFIX):

                file_patterns = cmdline.split(s[FILE_PREFS_PREFIX_LEN:])

                patterns.extend(file_patterns)

                for fp in file_patterns:

                    self.pattern_to_section[fp] = s

        if len(patterns) < len(sections):

            unknowns = [s for s in sections

                if not s.startswith(FILE_PREFS_PREFIX)]

            raise errors.UnknownRules(unknowns)

        elif patterns:

            self._globster = globbing._OrderedGlobster(patterns)

        else:

            self._globster = None

    def get_items(self, path):

        """See _RulesSearcher.get_items."""

        if self._globster is None:

            return ()

        pat = self._globster.match(path)

        if pat is None:

            return ()

        else:

            all = self._cfg[self.pattern_to_section[pat]]

            return tuple(all.items())

    def get_selected_items(self, path, names):

        """See _RulesSearcher.get_selected_items."""

        if self._globster is None:

            return ()

        pat = self._globster.match(path)

        if pat is None:

            return ()

        else:

            all = self._cfg[self.pattern_to_section[pat]]

            return tuple((k, all.get(k)) for k in names)

class _StackedRulesSearcher(_RulesSearcher):

    def __init__(self, searchers):

        """Construct a _RulesSearcher based on a stack of other ones.

        :param searchers: a sequence of searchers.

        """

        self.searchers = searchers

    def get_items(self, path):

        """See _RulesSearcher.get_items."""

        for searcher in self.searchers:

            result = searcher.get_items(path)

            if result:

                return result

        return ()

    def get_selected_items(self, path, names):

        """See _RulesSearcher.get_selected_items."""

        for searcher in self.searchers:

            result = searcher.get_selected_items(path, names)

            if result:

                return result

        return ()

def rules_filename():

    """Return the default rules filename."""

    return osutils.pathjoin(config.config_dir(), 'rules')

def reset_rules():

    global _per_user_searcher

    _per_user_searcher = _IniBasedRulesSearcher(rules_filename())

reset_rules()