Add pylint to depot_tools.

third_party/logilab/common/configuration.py

Index: third_party/logilab/common/configuration.py
diff --git a/third_party/logilab/common/configuration.py b/third_party/logilab/common/configuration.py
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+# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of logilab-common.
+#
+# logilab-common is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option) any
+# later version.
+#
+# logilab-common 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 Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
+"""Classes to handle advanced configuration in simple to complex applications.
+
+Allows to load the configuration from a file or from command line
+options, to generate a sample configuration file or to display
+program's usage. Fills the gap between optik/optparse and ConfigParser
+by adding data types (which are also available as a standalone optik
+extension in the `optik_ext` module).
+
+
+Quick start: simplest usage
+---------------------------
+
+.. python ::
+
+  >>> import sys
+  >>> from logilab.common.configuration import Configuration
+  >>> options = [('dothis', {'type':'yn', 'default': True, 'metavar': '<y or n>'}),
+  ...            ('value', {'type': 'string', 'metavar': '<string>'}),
+  ...            ('multiple', {'type': 'csv', 'default': ('yop',),
+  ...                          'metavar': '<comma separated values>',
+  ...                          'help': 'you can also document the option'}),
+  ...            ('number', {'type': 'int', 'default':2, 'metavar':'<int>'}),
+  ...           ]
+  >>> config = Configuration(options=options, name='My config')
+  >>> print config['dothis']
+  True
+  >>> print config['value']
+  None
+  >>> print config['multiple']
+  ('yop',)
+  >>> print config['number']
+  2
+  >>> print config.help()
+  Usage:  [options]
+
+  Options:
+    -h, --help            show this help message and exit
+    --dothis=<y or n>
+    --value=<string>
+    --multiple=<comma separated values>
+                          you can also document the option [current: none]
+    --number=<int>
+
+  >>> f = open('myconfig.ini', 'w')
+  >>> f.write('''[MY CONFIG]
+  ... number = 3
+  ... dothis = no
+  ... multiple = 1,2,3
+  ... ''')
+  >>> f.close()
+  >>> config.load_file_configuration('myconfig.ini')
+  >>> print config['dothis']
+  False
+  >>> print config['value']
+  None
+  >>> print config['multiple']
+  ['1', '2', '3']
+  >>> print config['number']
+  3
+  >>> sys.argv = ['mon prog', '--value', 'bacon', '--multiple', '4,5,6',
+  ...             'nonoptionargument']
+  >>> print config.load_command_line_configuration()
+  ['nonoptionargument']
+  >>> print config['value']
+  bacon
+  >>> config.generate_config()
+  # class for simple configurations which don't need the
+  # manager / providers model and prefer delegation to inheritance
+  #
+  # configuration values are accessible through a dict like interface
+  #
+  [MY CONFIG]
+
+  dothis=no
+
+  value=bacon
+
+  # you can also document the option
+  multiple=4,5,6
+
+  number=3
+  >>>
+"""
+__docformat__ = "restructuredtext en"
+
+__all__ = ('OptionsManagerMixIn', 'OptionsProviderMixIn',
+           'ConfigurationMixIn', 'Configuration',
+           'OptionsManager2ConfigurationAdapter')
+
+import os
+import sys
+import re
+from os.path import exists, expanduser
+from copy import copy
+from ConfigParser import ConfigParser, NoOptionError, NoSectionError, \
+     DuplicateSectionError
+from warnings import warn
+
+from logilab.common.compat import callable, raw_input, str_encode as _encode
+
+from logilab.common.textutils import normalize_text, unquote
+from logilab.common import optik_ext as optparse
+
+OptionError = optparse.OptionError
+
+REQUIRED = []
+
+class UnsupportedAction(Exception):
+    """raised by set_option when it doesn't know what to do for an action"""
+
+
+def _get_encoding(encoding, stream):
+    encoding = encoding or getattr(stream, 'encoding', None)
+    if not encoding:
+        import locale
+        encoding = locale.getpreferredencoding()
+    return encoding
+
+
+# validation functions ########################################################
+
+def choice_validator(optdict, name, value):
+    """validate and return a converted value for option of type 'choice'
+    """
+    if not value in optdict['choices']:
+        msg = "option %s: invalid value: %r, should be in %s"
+        raise optparse.OptionValueError(msg % (name, value, optdict['choices']))
+    return value
+
+def multiple_choice_validator(optdict, name, value):
+    """validate and return a converted value for option of type 'choice'
+    """
+    choices = optdict['choices']
+    values = optparse.check_csv(None, name, value)
+    for value in values:
+        if not value in choices:
+            msg = "option %s: invalid value: %r, should be in %s"
+            raise optparse.OptionValueError(msg % (name, value, choices))
+    return values
+
+def csv_validator(optdict, name, value):
+    """validate and return a converted value for option of type 'csv'
+    """
+    return optparse.check_csv(None, name, value)
+
+def yn_validator(optdict, name, value):
+    """validate and return a converted value for option of type 'yn'
+    """
+    return optparse.check_yn(None, name, value)
+
+def named_validator(optdict, name, value):
+    """validate and return a converted value for option of type 'named'
+    """
+    return optparse.check_named(None, name, value)
+
+def file_validator(optdict, name, value):
+    """validate and return a filepath for option of type 'file'"""
+    return optparse.check_file(None, name, value)
+
+def color_validator(optdict, name, value):
+    """validate and return a valid color for option of type 'color'"""
+    return optparse.check_color(None, name, value)
+
+def password_validator(optdict, name, value):
+    """validate and return a string for option of type 'password'"""
+    return optparse.check_password(None, name, value)
+
+def date_validator(optdict, name, value):
+    """validate and return a mx DateTime object for option of type 'date'"""
+    return optparse.check_date(None, name, value)
+
+def time_validator(optdict, name, value):
+    """validate and return a time object for option of type 'time'"""
+    return optparse.check_time(None, name, value)
+
+def bytes_validator(optdict, name, value):
+    """validate and return an integer for option of type 'bytes'"""
+    return optparse.check_bytes(None, name, value)
+
+
+VALIDATORS = {'string': unquote,
+              'int': int,
+              'float': float,
+              'file': file_validator,
+              'font': unquote,
+              'color': color_validator,
+              'regexp': re.compile,
+              'csv': csv_validator,
+              'yn': yn_validator,
+              'bool': yn_validator,
+              'named': named_validator,
+              'password': password_validator,
+              'date': date_validator,
+              'time': time_validator,
+              'bytes': bytes_validator,
+              'choice': choice_validator,
+              'multiple_choice': multiple_choice_validator,
+              }
+
+def _call_validator(opttype, optdict, option, value):
+    if opttype not in VALIDATORS:
+        raise Exception('Unsupported type "%s"' % opttype)
+    try:
+        return VALIDATORS[opttype](optdict, option, value)
+    except TypeError:
+        try:
+            return VALIDATORS[opttype](value)
+        except optparse.OptionValueError:
+            raise
+        except:
+            raise optparse.OptionValueError('%s value (%r) should be of type %s' %
+                                   (option, value, opttype))
+
+# user input functions ########################################################
+
+def input_password(optdict, question='password:'):
+    from getpass import getpass
+    while True:
+        value = getpass(question)
+        value2 = getpass('confirm: ')
+        if value == value2:
+            return value
+        print 'password mismatch, try again'
+
+def input_string(optdict, question):
+    value = raw_input(question).strip()
+    return value or None
+
+def _make_input_function(opttype):
+    def input_validator(optdict, question):
+        while True:
+            value = raw_input(question)
+            if not value.strip():
+                return None
+            try:
+                return _call_validator(opttype, optdict, None, value)
+            except optparse.OptionValueError, ex:
+                msg = str(ex).split(':', 1)[-1].strip()
+                print 'bad value: %s' % msg
+    return input_validator
+
+INPUT_FUNCTIONS = {
+    'string': input_string,
+    'password': input_password,
+    }
+
+for opttype in VALIDATORS.keys():
+    INPUT_FUNCTIONS.setdefault(opttype, _make_input_function(opttype))
+
+def expand_default(self, option):
+    """monkey patch OptionParser.expand_default since we have a particular
+    way to handle defaults to avoid overriding values in the configuration
+    file
+    """
+    if self.parser is None or not self.default_tag:
+        return option.help
+    optname = option._long_opts[0][2:]
+    try:
+        provider = self.parser.options_manager._all_options[optname]
+    except KeyError:
+        value = None
+    else:
+        optdict = provider.get_option_def(optname)
+        optname = provider.option_name(optname, optdict)
+        value = getattr(provider.config, optname, optdict)
+        value = format_option_value(optdict, value)
+    if value is optparse.NO_DEFAULT or not value:
+        value = self.NO_DEFAULT_VALUE
+    return option.help.replace(self.default_tag, str(value))
+
+
+def convert(value, optdict, name=''):
+    """return a validated value for an option according to its type
+
+    optional argument name is only used for error message formatting
+    """
+    try:
+        _type = optdict['type']
+    except KeyError:
+        # FIXME
+        return value
+    return _call_validator(_type, optdict, name, value)
+
+def comment(string):
+    """return string as a comment"""
+    lines = [line.strip() for line in string.splitlines()]
+    return '# ' + ('%s# ' % os.linesep).join(lines)
+
+def format_time(value):
+    if not value:
+        return '0'
+    if value != int(value):
+        return '%.2fs' % value
+    value = int(value)
+    nbmin, nbsec = divmod(value, 60)
+    if nbsec:
+        return '%ss' % value
+    nbhour, nbmin_ = divmod(nbmin, 60)
+    if nbmin_:
+        return '%smin' % nbmin
+    nbday, nbhour_ = divmod(nbhour, 24)
+    if nbhour_:
+        return '%sh' % nbhour
+    return '%sd' % nbday
+
+def format_bytes(value):
+    if not value:
+        return '0'
+    if value != int(value):
+        return '%.2fB' % value
+    value = int(value)
+    prevunit = 'B'
+    for unit in ('KB', 'MB', 'GB', 'TB'):
+        next, remain = divmod(value, 1024)
+        if remain:
+            return '%s%s' % (value, prevunit)
+        prevunit = unit
+        value = next
+    return '%s%s' % (value, unit)
+
+def format_option_value(optdict, value):
+    """return the user input's value from a 'compiled' value"""
+    if isinstance(value, (list, tuple)):
+        value = ','.join(value)
+    elif isinstance(value, dict):
+        value = ','.join(['%s:%s' % (k, v) for k, v in value.items()])
+    elif hasattr(value, 'match'): # optdict.get('type') == 'regexp'
+        # compiled regexp
+        value = value.pattern
+    elif optdict.get('type') == 'yn':
+        value = value and 'yes' or 'no'
+    elif isinstance(value, (str, unicode)) and value.isspace():
+        value = "'%s'" % value
+    elif optdict.get('type') == 'time' and isinstance(value, (float, int, long)):
+        value = format_time(value)
+    elif optdict.get('type') == 'bytes' and hasattr(value, '__int__'):
+        value = format_bytes(value)
+    return value
+
+def ini_format_section(stream, section, options, encoding=None, doc=None):
+    """format an options section using the INI format"""
+    encoding = _get_encoding(encoding, stream)
+    if doc:
+        print >> stream, _encode(comment(doc), encoding)
+    print >> stream, '[%s]' % section
+    ini_format(stream, options, encoding)
+
+def ini_format(stream, options, encoding):
+    """format options using the INI format"""
+    for optname, optdict, value in options:
+        value = format_option_value(optdict, value)
+        help = optdict.get('help')
+        if help:
+            help = normalize_text(help, line_len=79, indent='# ')
+            print >> stream
+            print >> stream, _encode(help, encoding)
+        else:
+            print >> stream
+        if value is None:
+            print >> stream, '#%s=' % optname
+        else:
+            value = _encode(value, encoding).strip()
+            print >> stream, '%s=%s' % (optname, value)
+
+format_section = ini_format_section
+
+def rest_format_section(stream, section, options, encoding=None, doc=None):
+    """format an options section using the INI format"""
+    encoding = _get_encoding(encoding, stream)
+    if section:
+        print >> stream, '%s\n%s' % (section, "'"*len(section))
+    if doc:
+        print >> stream, _encode(normalize_text(doc, line_len=79, indent=''),
+                                 encoding)
+        print >> stream
+    for optname, optdict, value in options:
+        help = optdict.get('help')
+        print >> stream, ':%s:' % optname
+        if help:
+            help = normalize_text(help, line_len=79, indent='  ')
+            print >> stream, _encode(help, encoding)
+        if value:
+            value = _encode(format_option_value(optdict, value), encoding)
+            print >> stream, ''
+            print >> stream, '  Default: ``%s``' % value.replace("`` ", "```` ``")
+
+
+class OptionsManagerMixIn(object):
+    """MixIn to handle a configuration from both a configuration file and
+    command line options
+    """
+
+    def __init__(self, usage, config_file=None, version=None, quiet=0):
+        self.config_file = config_file
+        self.reset_parsers(usage, version=version)
+        # list of registered options providers
+        self.options_providers = []
+        # dictionary associating option name to checker
+        self._all_options = {}
+        self._short_options = {}
+        self._nocallback_options = {}
+        self._mygroups = dict()
+        # verbosity
+        self.quiet = quiet
+        self._maxlevel = 0
+
+    def reset_parsers(self, usage='', version=None):
+        # configuration file parser
+        self.cfgfile_parser = ConfigParser()
+        # command line parser
+        self.cmdline_parser = optparse.OptionParser(usage=usage, version=version)
+        self.cmdline_parser.options_manager = self
+        self._optik_option_attrs = set(self.cmdline_parser.option_class.ATTRS)
+
+    def register_options_provider(self, provider, own_group=True):
+        """register an options provider"""
+        assert provider.priority <= 0, "provider's priority can't be >= 0"
+        for i in range(len(self.options_providers)):
+            if provider.priority > self.options_providers[i].priority:
+                self.options_providers.insert(i, provider)
+                break
+        else:
+            self.options_providers.append(provider)
+        non_group_spec_options = [option for option in provider.options
+                                  if 'group' not in option[1]]
+        groups = getattr(provider, 'option_groups', ())
+        if own_group and non_group_spec_options:
+            self.add_option_group(provider.name.upper(), provider.__doc__,
+                                  non_group_spec_options, provider)
+        else:
+            for opt, optdict in non_group_spec_options:
+                self.add_optik_option(provider, self.cmdline_parser, opt, optdict)
+        for gname, gdoc in groups:
+            gname = gname.upper()
+            goptions = [option for option in provider.options
+                        if option[1].get('group', '').upper() == gname]
+            self.add_option_group(gname, gdoc, goptions, provider)
+
+    def add_option_group(self, group_name, doc, options, provider):
+        """add an option group including the listed options
+        """
+        assert options
+        # add option group to the command line parser
+        if group_name in self._mygroups:
+            group = self._mygroups[group_name]
+        else:
+            group = optparse.OptionGroup(self.cmdline_parser,
+                                         title=group_name.capitalize())
+            self.cmdline_parser.add_option_group(group)
+            group.level = provider.level
+            self._mygroups[group_name] = group
+            # add section to the config file
+            if group_name != "DEFAULT":
+                self.cfgfile_parser.add_section(group_name)
+        # add provider's specific options
+        for opt, optdict in options:
+            self.add_optik_option(provider, group, opt, optdict)
+
+    def add_optik_option(self, provider, optikcontainer, opt, optdict):
+        if 'inputlevel' in optdict:
+            warn('[0.50] "inputlevel" in option dictionary for %s is deprecated,'
+                 ' use "level"' % opt, DeprecationWarning)
+            optdict['level'] = optdict.pop('inputlevel')
+        args, optdict = self.optik_option(provider, opt, optdict)
+        option = optikcontainer.add_option(*args, **optdict)
+        self._all_options[opt] = provider
+        self._maxlevel = max(self._maxlevel, option.level or 0)
+
+    def optik_option(self, provider, opt, optdict):
+        """get our personal option definition and return a suitable form for
+        use with optik/optparse
+        """
+        optdict = copy(optdict)
+        others = {}
+        if 'action' in optdict:
+            self._nocallback_options[provider] = opt
+        else:
+            optdict['action'] = 'callback'
+            optdict['callback'] = self.cb_set_provider_option
+        # default is handled here and *must not* be given to optik if you
+        # want the whole machinery to work
+        if 'default' in optdict:
+            if (optparse.OPTPARSE_FORMAT_DEFAULT and 'help' in optdict and
+                optdict.get('default') is not None and
+                not optdict['action'] in ('store_true', 'store_false')):
+                optdict['help'] += ' [current: %default]'
+            del optdict['default']
+        args = ['--' + str(opt)]
+        if 'short' in optdict:
+            self._short_options[optdict['short']] = opt
+            args.append('-' + optdict['short'])
+            del optdict['short']
+        # cleanup option definition dict before giving it to optik
+        for key in optdict.keys():
+            if not key in self._optik_option_attrs:
+                optdict.pop(key)
+        return args, optdict
+
+    def cb_set_provider_option(self, option, opt, value, parser):
+        """optik callback for option setting"""
+        if opt.startswith('--'):
+            # remove -- on long option
+            opt = opt[2:]
+        else:
+            # short option, get its long equivalent
+            opt = self._short_options[opt[1:]]
+        # trick since we can't set action='store_true' on options
+        if value is None:
+            value = 1
+        self.global_set_option(opt, value)
+
+    def global_set_option(self, opt, value):
+        """set option on the correct option provider"""
+        self._all_options[opt].set_option(opt, value)
+
+    def generate_config(self, stream=None, skipsections=(), encoding=None):
+        """write a configuration file according to the current configuration
+        into the given stream or stdout
+        """
+        options_by_section = {}
+        sections = []
+        for provider in self.options_providers:
+            for section, options in provider.options_by_section():
+                if section is None:
+                    section = provider.name
+                if section in skipsections:
+                    continue
+                options = [(n, d, v) for (n, d, v) in options
+                           if d.get('type') is not None]
+                if not options:
+                    continue
+                if not section in sections:
+                    sections.append(section)
+                alloptions = options_by_section.setdefault(section, [])
+                alloptions += options
+        stream = stream or sys.stdout
+        encoding = _get_encoding(encoding, stream)
+        printed = False
+        for section in sections:
+            if printed:
+                print >> stream, '\n'
+            format_section(stream, section.upper(), options_by_section[section],
+                           encoding)
+            printed = True
+
+    def generate_manpage(self, pkginfo, section=1, stream=None):
+        """write a man page for the current configuration into the given
+        stream or stdout
+        """
+        self._monkeypatch_expand_default()
+        try:
+            optparse.generate_manpage(self.cmdline_parser, pkginfo,
+                                      section, stream=stream or sys.stdout,
+                                      level=self._maxlevel)
+        finally:
+            self._unmonkeypatch_expand_default()
+
+    # initialization methods ##################################################
+
+    def load_provider_defaults(self):
+        """initialize configuration using default values"""
+        for provider in self.options_providers:
+            provider.load_defaults()
+
+    def load_file_configuration(self, config_file=None):
+        """load the configuration from file"""
+        self.read_config_file(config_file)
+        self.load_config_file()
+
+    def read_config_file(self, config_file=None):
+        """read the configuration file but do not load it (i.e. dispatching
+        values to each options provider)
+        """
+        helplevel = 1
+        while helplevel <= self._maxlevel:
+            opt = '-'.join(['long'] * helplevel) + '-help'
+            if opt in self._all_options:
+                break # already processed
+            def helpfunc(option, opt, val, p, level=helplevel):
+                print self.help(level)
+                sys.exit(0)
+            helpmsg = '%s verbose help.' % ' '.join(['more'] * helplevel)
+            optdict = {'action' : 'callback', 'callback' : helpfunc,
+                       'help' : helpmsg}
+            provider = self.options_providers[0]
+            self.add_optik_option(provider, self.cmdline_parser, opt, optdict)
+            provider.options += ( (opt, optdict), )
+            helplevel += 1
+        if config_file is None:
+            config_file = self.config_file
+        if config_file is not None:
+            config_file = expanduser(config_file)
+        if config_file and exists(config_file):
+            parser = self.cfgfile_parser
+            parser.read([config_file])
+            # normalize sections'title
+            for sect, values in parser._sections.items():
+                if not sect.isupper() and values:
+                    parser._sections[sect.upper()] = values
+        elif not self.quiet:
+            msg = 'No config file found, using default configuration'
+            print >> sys.stderr, msg
+            return
+
+    def input_config(self, onlysection=None, inputlevel=0, stream=None):
+        """interactively get configuration values by asking to the user and generate
+        a configuration file
+        """
+        if onlysection is not None:
+            onlysection = onlysection.upper()
+        for provider in self.options_providers:
+            for section, option, optdict in provider.all_options():
+                if onlysection is not None and section != onlysection:
+                    continue
+                if not 'type' in optdict:
+                    # ignore action without type (callback, store_true...)
+                    continue
+                provider.input_option(option, optdict, inputlevel)
+        # now we can generate the configuration file
+        if stream is not None:
+            self.generate_config(stream)
+
+    def load_config_file(self):
+        """dispatch values previously read from a configuration file to each
+        options provider)
+        """
+        parser = self.cfgfile_parser
+        for provider in self.options_providers:
+            for section, option, optdict in provider.all_options():
+                try:
+                    value = parser.get(section, option)
+                    provider.set_option(option, value, optdict=optdict)
+                except (NoSectionError, NoOptionError), ex:
+                    continue
+
+    def load_configuration(self, **kwargs):
+        """override configuration according to given parameters
+        """
+        for opt, opt_value in kwargs.items():
+            opt = opt.replace('_', '-')
+            provider = self._all_options[opt]
+            provider.set_option(opt, opt_value)
+
+    def load_command_line_configuration(self, args=None):
+        """override configuration according to command line parameters
+
+        return additional arguments
+        """
+        self._monkeypatch_expand_default()
+        try:
+            if args is None:
+                args = sys.argv[1:]
+            else:
+                args = list(args)
+            (options, args) = self.cmdline_parser.parse_args(args=args)
+            for provider in self._nocallback_options.keys():
+                config = provider.config
+                for attr in config.__dict__.keys():
+                    value = getattr(options, attr, None)
+                    if value is None:
+                        continue
+                    setattr(config, attr, value)
+            return args
+        finally:
+            self._unmonkeypatch_expand_default()
+
+
+    # help methods ############################################################
+
+    def add_help_section(self, title, description, level=0):
+        """add a dummy option section for help purpose """
+        group = optparse.OptionGroup(self.cmdline_parser,
+                                     title=title.capitalize(),
+                                     description=description)
+        group.level = level
+        self._maxlevel = max(self._maxlevel, level)
+        self.cmdline_parser.add_option_group(group)
+
+    def _monkeypatch_expand_default(self):
+        # monkey patch optparse to deal with our default values
+        try:
+            self.__expand_default_backup = optparse.HelpFormatter.expand_default
+            optparse.HelpFormatter.expand_default = expand_default
+        except AttributeError:
+            # python < 2.4: nothing to be done
+            pass
+    def _unmonkeypatch_expand_default(self):
+        # remove monkey patch
+        if hasattr(optparse.HelpFormatter, 'expand_default'):
+            # unpatch optparse to avoid side effects
+            optparse.HelpFormatter.expand_default = self.__expand_default_backup
+
+    def help(self, level=0):
+        """return the usage string for available options """
+        self.cmdline_parser.formatter.output_level = level
+        self._monkeypatch_expand_default()
+        try:
+            return self.cmdline_parser.format_help()
+        finally:
+            self._unmonkeypatch_expand_default()
+
+
+class Method(object):
+    """used to ease late binding of default method (so you can define options
+    on the class using default methods on the configuration instance)
+    """
+    def __init__(self, methname):
+        self.method = methname
+        self._inst = None
+
+    def bind(self, instance):
+        """bind the method to its instance"""
+        if self._inst is None:
+            self._inst = instance
+
+    def __call__(self, *args, **kwargs):
+        assert self._inst, 'unbound method'
+        return getattr(self._inst, self.method)(*args, **kwargs)
+
+
+class OptionsProviderMixIn(object):
+    """Mixin to provide options to an OptionsManager"""
+
+    # those attributes should be overridden
+    priority = -1
+    name = 'default'
+    options = ()
+    level = 0
+
+    def __init__(self):
+        self.config = optparse.Values()
+        for option in self.options:
+            try:
+                option, optdict = option
+            except ValueError:
+                raise Exception('Bad option: %r' % option)
+            if isinstance(optdict.get('default'), Method):
+                optdict['default'].bind(self)
+            elif isinstance(optdict.get('callback'), Method):
+                optdict['callback'].bind(self)
+        self.load_defaults()
+
+    def load_defaults(self):
+        """initialize the provider using default values"""
+        for opt, optdict in self.options:
+            action = optdict.get('action')
+            if action != 'callback':
+                # callback action have no default
+                default = self.option_default(opt, optdict)
+                if default is REQUIRED:
+                    continue
+                self.set_option(opt, default, action, optdict)
+
+    def option_default(self, opt, optdict=None):
+        """return the default value for an option"""
+        if optdict is None:
+            optdict = self.get_option_def(opt)
+        default = optdict.get('default')
+        if callable(default):
+            default = default()
+        return default
+
+    def option_name(self, opt, optdict=None):
+        """get the config attribute corresponding to opt
+        """
+        if optdict is None:
+            optdict = self.get_option_def(opt)
+        return optdict.get('dest', opt.replace('-', '_'))
+
+    def option_value(self, opt):
+        """get the current value for the given option"""
+        return getattr(self.config, self.option_name(opt), None)
+
+    def set_option(self, opt, value, action=None, optdict=None):
+        """method called to set an option (registered in the options list)
+        """
+        # print "************ setting option", opt," to value", value
+        if optdict is None:
+            optdict = self.get_option_def(opt)
+        if value is not None:
+            value = convert(value, optdict, opt)
+        if action is None:
+            action = optdict.get('action', 'store')
+        if optdict.get('type') == 'named': # XXX need specific handling
+            optname = self.option_name(opt, optdict)
+            currentvalue = getattr(self.config, optname, None)
+            if currentvalue:
+                currentvalue.update(value)
+                value = currentvalue
+        if action == 'store':
+            setattr(self.config, self.option_name(opt, optdict), value)
+        elif action in ('store_true', 'count'):
+            setattr(self.config, self.option_name(opt, optdict), 0)
+        elif action == 'store_false':
+            setattr(self.config, self.option_name(opt, optdict), 1)
+        elif action == 'append':
+            opt = self.option_name(opt, optdict)
+            _list = getattr(self.config, opt, None)
+            if _list is None:
+                if isinstance(value, (list, tuple)):
+                    _list = value
+                elif value is not None:
+                    _list = []
+                    _list.append(value)
+                setattr(self.config, opt, _list)
+            elif isinstance(_list, tuple):
+                setattr(self.config, opt, _list + (value,))
+            else:
+                _list.append(value)
+        elif action == 'callback':
+            optdict['callback'](None, opt, value, None)
+        else:
+            raise UnsupportedAction(action)
+
+    def input_option(self, option, optdict, inputlevel=99):
+        default = self.option_default(option, optdict)
+        if default is REQUIRED:
+            defaultstr = '(required): '
+        elif optdict.get('level', 0) > inputlevel:
+            return
+        elif optdict['type'] == 'password' or default is None:
+            defaultstr = ': '
+        else:
+            defaultstr = '(default: %s): ' % format_option_value(optdict, default)
+        print ':%s:' % option
+        print optdict.get('help') or option
+        inputfunc = INPUT_FUNCTIONS[optdict['type']]
+        value = inputfunc(optdict, defaultstr)
+        while default is REQUIRED and not value:
+            print 'please specify a value'
+            value = inputfunc(optdict, '%s: ' % option)
+        if value is None and default is not None:
+            value = default
+        self.set_option(option, value, optdict=optdict)
+
+    def get_option_def(self, opt):
+        """return the dictionary defining an option given it's name"""
+        assert self.options
+        for option in self.options:
+            if option[0] == opt:
+                return option[1]
+        raise OptionError('no such option %s in section %r'
+                          % (opt, self.name), opt)
+
+
+    def all_options(self):
+        """return an iterator on available options for this provider
+        option are actually described by a 3-uple:
+        (section, option name, option dictionary)
+        """
+        for section, options in self.options_by_section():
+            if section is None:
+                if self.name is None:
+                    continue
+                section = self.name.upper()
+            for option, optiondict, value in options:
+                yield section, option, optiondict
+
+    def options_by_section(self):
+        """return an iterator on options grouped by section
+
+        (section, [list of (optname, optdict, optvalue)])
+        """
+        sections = {}
+        for optname, optdict in self.options:
+            sections.setdefault(optdict.get('group'), []).append(
+                (optname, optdict, self.option_value(optname)))
+        if None in sections:
+            yield None, sections.pop(None)
+        for section, options in sections.items():
+            yield section.upper(), options
+
+    def options_and_values(self, options=None):
+        if options is None:
+            options = self.options
+        for optname, optdict in options:
+            yield (optname, optdict, self.option_value(optname))
+
+
+class ConfigurationMixIn(OptionsManagerMixIn, OptionsProviderMixIn):
+    """basic mixin for simple configurations which don't need the
+    manager / providers model
+    """
+    def __init__(self, *args, **kwargs):
+        if not args:
+            kwargs.setdefault('usage', '')
+        kwargs.setdefault('quiet', 1)
+        OptionsManagerMixIn.__init__(self, *args, **kwargs)
+        OptionsProviderMixIn.__init__(self)
+        if not getattr(self, 'option_groups', None):
+            self.option_groups = []
+            for option, optdict in self.options:
+                try:
+                    gdef = (optdict['group'].upper(), '')
+                except KeyError:
+                    continue
+                if not gdef in self.option_groups:
+                    self.option_groups.append(gdef)
+        self.register_options_provider(self, own_group=0)
+
+    def register_options(self, options):
+        """add some options to the configuration"""
+        options_by_group = {}
+        for optname, optdict in options:
+            options_by_group.setdefault(optdict.get('group', self.name.upper()), []).append((optname, optdict))
+        for group, options in options_by_group.items():
+            self.add_option_group(group, None, options, self)
+        self.options += tuple(options)
+
+    def load_defaults(self):
+        OptionsProviderMixIn.load_defaults(self)
+
+    def __iter__(self):
+        return iter(self.config.__dict__.iteritems())
+
+    def __getitem__(self, key):
+        try:
+            return getattr(self.config, self.option_name(key))
+        except (optparse.OptionValueError, AttributeError):
+            raise KeyError(key)
+
+    def __setitem__(self, key, value):
+        self.set_option(key, value)
+
+    def get(self, key, default=None):
+        try:
+            return getattr(self.config, self.option_name(key))
+        except (OptionError, AttributeError):
+            return default
+
+
+class Configuration(ConfigurationMixIn):
+    """class for simple configurations which don't need the
+    manager / providers model and prefer delegation to inheritance
+
+    configuration values are accessible through a dict like interface
+    """
+
+    def __init__(self, config_file=None, options=None, name=None,
+                 usage=None, doc=None, version=None):
+        if options is not None:
+            self.options = options
+        if name is not None:
+            self.name = name
+        if doc is not None:
+            self.__doc__ = doc
+        super(Configuration, self).__init__(config_file=config_file, usage=usage, version=version)
+
+
+class OptionsManager2ConfigurationAdapter(object):
+    """Adapt an option manager to behave like a
+    `logilab.common.configuration.Configuration` instance
+    """
+    def __init__(self, provider):
+        self.config = provider
+
+    def __getattr__(self, key):
+        return getattr(self.config, key)
+
+    def __getitem__(self, key):
+        provider = self.config._all_options[key]
+        try:
+            return getattr(provider.config, provider.option_name(key))
+        except AttributeError:
+            raise KeyError(key)
+
+    def __setitem__(self, key, value):
+        self.config.global_set_option(self.config.option_name(key), value)
+
+    def get(self, key, default=None):
+        provider = self.config._all_options[key]
+        try:
+            return getattr(provider.config, provider.option_name(key))
+        except AttributeError:
+            return default
+
+
+def read_old_config(newconfig, changes, configfile):
+    """initialize newconfig from a deprecated configuration file
+
+    possible changes:
+    * ('renamed', oldname, newname)
+    * ('moved', option, oldgroup, newgroup)
+    * ('typechanged', option, oldtype, newvalue)
+    """
+    # build an index of changes
+    changesindex = {}
+    for action in changes:
+        if action[0] == 'moved':
+            option, oldgroup, newgroup = action[1:]
+            changesindex.setdefault(option, []).append((action[0], oldgroup, newgroup))
+            continue
+        if action[0] == 'renamed':
+            oldname, newname = action[1:]
+            changesindex.setdefault(newname, []).append((action[0], oldname))
+            continue
+        if action[0] == 'typechanged':
+            option, oldtype, newvalue = action[1:]
+            changesindex.setdefault(option, []).append((action[0], oldtype, newvalue))
+            continue
+        if action[1] in ('added', 'removed'):
+            continue # nothing to do here
+        raise Exception('unknown change %s' % action[0])
+    # build a config object able to read the old config
+    options = []
+    for optname, optdef in newconfig.options:
+        for action in changesindex.pop(optname, ()):
+            if action[0] == 'moved':
+                oldgroup, newgroup = action[1:]
+                optdef = optdef.copy()
+                optdef['group'] = oldgroup
+            elif action[0] == 'renamed':
+                optname = action[1]
+            elif action[0] == 'typechanged':
+                oldtype = action[1]
+                optdef = optdef.copy()
+                optdef['type'] = oldtype
+        options.append((optname, optdef))
+    if changesindex:
+        raise Exception('unapplied changes: %s' % changesindex)
+    oldconfig = Configuration(options=options, name=newconfig.name)
+    # read the old config
+    oldconfig.load_file_configuration(configfile)
+    # apply values reverting changes
+    changes.reverse()
+    done = set()
+    for action in changes:
+        if action[0] == 'renamed':
+            oldname, newname = action[1:]
+            newconfig[newname] = oldconfig[oldname]
+            done.add(newname)
+        elif action[0] == 'typechanged':
+            optname, oldtype, newvalue = action[1:]
+            newconfig[optname] = newvalue
+            done.add(optname)
+    for optname, optdef in newconfig.options:
+        if optdef.get('type') and not optname in done:
+            newconfig.set_option(optname, oldconfig[optname], optdict=optdef)
+
+
+def merge_options(options):
+    """preprocess options to remove duplicate"""
+    alloptions = {}
+    options = list(options)
+    for i in range(len(options)-1, -1, -1):
+        optname, optdict = options[i]
+        if optname in alloptions:
+            options.pop(i)
+            alloptions[optname].update(optdict)
+        else:
+            alloptions[optname] = optdict
+    return tuple(options)