tiramisu/tiramisu/setting.py

402 lines
15 KiB
Python

# -*- coding: utf-8 -*-
"sets the options of the configuration objects Config object itself"
# Copyright (C) 2012-2013 Team tiramisu (see AUTHORS for all contributors)
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# The original `Config` design model is unproudly borrowed from
# the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
# the whole pypy projet is under MIT licence
# ____________________________________________________________
from time import time
from copy import copy
from tiramisu.error import RequirementError, PropertiesOptionError
from tiramisu.i18n import _
expires_time = 5
ro_remove = ('permissive', 'hidden')
ro_append = ('frozen', 'disabled', 'validator', 'everything_frozen', 'mandatory')
rw_remove = ('permissive', 'everything_frozen', 'mandatory')
rw_append = ('frozen', 'disabled', 'validator', 'hidden')
class _const:
"""convenient class that emulates a module
and builds constants (that is, unique names)"""
class ConstError(TypeError):
pass
def __setattr__(self, name, value):
if name in self.__dict__:
raise self.ConstError, _("Can't rebind group ({})").format(name)
self.__dict__[name] = value
def __delattr__(self, name):
if name in self.__dict__:
raise self.ConstError, _("Can't unbind group ({})").format(name)
raise ValueError(name)
# ____________________________________________________________
class GroupModule(_const):
"emulates a module to manage unique group (OptionDescription) names"
class GroupType(str):
"""allowed normal group (OptionDescription) names
*normal* means : groups that are not master
"""
pass
class DefaultGroupType(GroupType):
"""groups that are default (typically 'default')"""
pass
class MasterGroupType(GroupType):
"""allowed normal group (OptionDescription) names
*master* means : groups that have the 'master' attribute set
"""
pass
# setting.groups (emulates a module)
groups = GroupModule()
def populate_groups():
"populates the available groups in the appropriate namespaces"
groups.master = groups.MasterGroupType('master')
groups.default = groups.DefaultGroupType('default')
groups.family = groups.GroupType('family')
# names are in the module now
populate_groups()
# ____________________________________________________________
class OwnerModule(_const):
"""emulates a module to manage unique owner names.
owners are living in `Config._cfgimpl_value_owners`
"""
class Owner(str):
"""allowed owner names
"""
pass
class DefaultOwner(Owner):
"""groups that are default (typically 'default')"""
pass
# setting.owners (emulates a module)
owners = OwnerModule()
def populate_owners():
"""populates the available owners in the appropriate namespaces
- 'user' is the generic is the generic owner.
- 'default' is the config owner after init time
"""
setattr(owners, 'default', owners.DefaultOwner('default'))
setattr(owners, 'user', owners.Owner('user'))
def add_owner(name):
"""
:param name: the name of the new owner
"""
setattr(owners, name, owners.Owner(name))
setattr(owners, 'add_owner', add_owner)
# names are in the module now
populate_owners()
class MultiTypeModule(_const):
"namespace for the master/slaves"
class MultiType(str):
pass
class DefaultMultiType(MultiType):
pass
class MasterMultiType(MultiType):
pass
class SlaveMultiType(MultiType):
pass
multitypes = MultiTypeModule()
def populate_multitypes():
"populates the master/slave namespace"
setattr(multitypes, 'default', multitypes.DefaultMultiType('default'))
setattr(multitypes, 'master', multitypes.MasterMultiType('master'))
setattr(multitypes, 'slave', multitypes.SlaveMultiType('slave'))
populate_multitypes()
class Property(object):
"a property is responsible of the option's value access rules"
__slots__ = ('_setting', '_properties', '_opt')
def __init__(self, setting, prop, opt=None):
self._opt = opt
self._setting = setting
self._properties = prop
def append(self, propname):
self._properties.add(propname)
self._setting._set_properties(self._properties, self._opt)
self._setting.context.cfgimpl_reset_cache()
def remove(self, propname):
if propname in self._properties:
self._properties.remove(propname)
self._setting._set_properties(self._properties, self._opt)
self._setting.context.cfgimpl_reset_cache()
def __contains__(self, propname):
return propname in self._properties
def __repr__(self):
return str(list(self._properties))
#____________________________________________________________
class Setting(object):
"``Config()``'s configuration options"
__slots__ = ('context', '_properties', '_permissives', '_owner', '_cache')
def __init__(self, context):
# properties attribute: the name of a property enables this property
# key is None for global properties
self._properties = {None: set(('expire', 'validator'))}
# permissive properties
self._permissives = {}
# generic owner
self._owner = owners.user
self.context = context
self._cache = {}
#____________________________________________________________
# properties methods
def __contains__(self, propname):
return propname in self._get_properties()
def __repr__(self):
return str(list(self._get_properties()))
def __getitem__(self, opt):
return Property(self, self._get_properties(opt), opt)
def __setitem__(self, opt, value):
raise ValueError('you must only append/remove properties')
def _get_properties(self, opt=None, is_apply_req=True):
if opt is None:
props = self._properties.get(opt, set())
else:
exp = None
if opt in self._cache:
exp = time()
props, created = self._cache[opt]
if exp < created:
return props
if is_apply_req:
apply_requires(opt, self.context)
props = self._properties.get(opt, opt._properties)
self._set_cache(opt, props, exp)
return props
def append(self, propname):
"puts property propname in the Config's properties attribute"
Property(self, self._get_properties()).append(propname)
def remove(self, propname):
"deletes property propname in the Config's properties attribute"
Property(self, self._get_properties()).remove(propname)
def _set_properties(self, properties, opt=None):
"""save properties for specified opt
(never save properties if same has option properties)
"""
if opt is None:
self._properties[opt] = properties
else:
if opt._properties == properties:
if opt in self._properties:
del(self._properties[opt])
else:
self._properties[opt] = properties
#____________________________________________________________
def validate_properties(self, opt_or_descr, is_descr, is_write,
value=None, force_permissive=False,
force_properties=None):
#opt properties
properties = copy(self._get_properties(opt_or_descr))
#remove opt permissive
properties -= self._get_permissive(opt_or_descr)
#remove global permissive if need
self_properties = copy(self._get_properties())
if force_permissive is True or 'permissive' in self_properties:
properties -= self._get_permissive()
#global properties
if force_properties is not None:
self_properties.update(force_properties)
#calc properties
properties &= self_properties
#mandatory and frozen are special properties
if is_descr:
properties -= frozenset(('mandatory', 'frozen'))
else:
if 'mandatory' in properties and \
not self.context.cfgimpl_get_values()._is_empty(opt_or_descr,
value):
properties.remove('mandatory')
if is_write and 'everything_frozen' in self_properties:
properties.add('frozen')
elif 'frozen' in properties and not is_write:
properties.remove('frozen')
if properties != frozenset():
if 'frozen' in properties:
raise_text = 'cannot change the value for option {0} this option is frozen'
else:
raise_text = "trying to access to an option named: {0} with properties {1}"
raise PropertiesOptionError(_(raise_text).format(opt_or_descr._name,
str(list(properties))),
list(properties))
def _get_permissive(self, opt=None):
return self._permissives.get(opt, frozenset())
def set_permissive(self, permissive, opt=None):
if not isinstance(permissive, tuple):
raise TypeError(_('permissive must be a tuple'))
self._permissives[opt] = frozenset(permissive)
#____________________________________________________________
def setowner(self, owner):
":param owner: sets the default value for owner at the Config level"
if not isinstance(owner, owners.Owner):
raise TypeError(_("invalid generic owner {0}").format(str(owner)))
self._owner = owner
def getowner(self):
return self._owner
#____________________________________________________________
def _read(self, remove, append):
for prop in remove:
self.remove(prop)
for prop in append:
self.append(prop)
def read_only(self):
"convenience method to freeze, hidde and disable"
self._read(ro_remove, ro_append)
def read_write(self):
"convenience method to freeze, hidde and disable"
self._read(rw_remove, rw_append)
def _set_cache(self, opt, props, exp):
if 'expire' in self:
if exp is None:
exp = time()
self._cache[opt] = (props, time() + expires_time)
def reset_cache(self, only_expired):
if only_expired:
exp = time()
keys = self._cache.keys()
for key in keys:
props, created = self._cache[key]
if exp > created:
del(self._cache[key])
else:
self._cache.clear()
def apply_requires(opt, config):
"carries out the jit (just in time requirements between options"
def build_actions(requires):
"action are hide, show, enable, disable..."
trigger_actions = {}
for require in requires:
action = require[2]
trigger_actions.setdefault(action, []).append(require)
return trigger_actions
#for symlink
if hasattr(opt, '_requires') and opt._requires is not None:
# filters the callbacks
settings = config.cfgimpl_get_settings()
setting = Property(settings, settings._get_properties(opt, False), opt)
trigger_actions = build_actions(opt._requires)
descr = config.cfgimpl_get_context().cfgimpl_get_description()
optpath = descr.impl_get_path_by_opt(opt)
for requires in trigger_actions.values():
matches = False
for require in requires:
if len(require) == 3:
option, expected, action = require
inverse = False
transitive = True
same_action = True
elif len(require) == 4:
option, expected, action, inverse = require
transitive = True
same_action = True
elif len(require) == 5:
option, expected, action, inverse, transitive = require
same_action = True
elif len(require) == 6:
option, expected, action, inverse, transitive, same_action = require
path = descr.impl_get_path_by_opt(option)
if path == optpath or path.startswith(optpath + '.'):
raise RequirementError(_("malformed requirements "
"imbrication detected for option: '{0}' "
"with requirement on: '{1}'").format(optpath, path))
try:
value = config.cfgimpl_get_context()._getattr(path, force_permissive=True)
except PropertiesOptionError, err:
if not transitive:
continue
properties = err.proptype
if same_action and action not in properties:
raise RequirementError(_("option '{0}' has requirement's property error: "
"{1} {2}").format(opt._name, path, properties))
#transitive action, force expected
value = expected
inverse = False
except AttributeError:
raise AttributeError(_("required option not found: "
"{0}").format(path))
if value == expected:
if inverse:
setting.remove(action)
else:
setting.append(action)
matches = True
# the calculation cannot be carried out
break
# no requirement has been triggered, then just reverse the action
if not matches:
if inverse:
setting.append(action)
else:
setting.remove(action)