Merge branch 'master' of ssh://git.labs.libre-entreprise.org/gitroot/tiramisu
[tiramisu.git] / tiramisu / setting.py
index c2140a9..86f900e 100644 (file)
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 "sets the options of the configuration objects Config object itself"
-# Copyright (C) 2012 Team tiramisu (see AUTHORS for all contributors)
+# 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 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
+import weakref
+from tiramisu.error import (RequirementError, PropertiesOptionError,
+                            ConstError, ConfigError)
+from tiramisu.i18n import _
 
-# available group_type values
-_group_name = ('default', 'family', 'group')
-groups_has_master = ('group', )
-class Group(str): pass
-group_types = tuple(Group(i) for i in _group_name)
 
-class Setting():
+default_encoding = 'utf-8'
+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')
+default_properties = ('expire', 'validator')
+
+
+class StorageType:
+    default_storage = 'dictionary'
+    storage_type = None
+
+    def set_storage(self, name):
+        if self.storage_type is not None:
+            raise ConfigError(_('storage_type is already set, cannot rebind it'))
+        self.storage_type = name
+
+    def get_storage(self):
+        if self.storage_type is None:
+            self.storage_type = self.default_storage
+        storage = self.storage_type
+        return 'tiramisu.storage.{0}.storage'.format(
+            storage)
+
+
+storage_type = StorageType()
+
+
+class _NameSpace:
+    """convenient class that emulates a module
+    and builds constants (that is, unique names)"""
+
+    def __setattr__(self, name, value):
+        if name in self.__dict__:
+            raise ConstError(_("can't rebind {0}").format(name))
+        self.__dict__[name] = value
+
+    def __delattr__(self, name):
+        if name in self.__dict__:
+            raise ConstError(_("can't unbind {0}").format(name))
+        raise ValueError(name)
+
+
+# ____________________________________________________________
+class GroupModule(_NameSpace):
+    "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(_NameSpace):
+    """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 addowner(name):
+        """
+        :param name: the name of the new owner
+        """
+        setattr(owners, name, owners.Owner(name))
+    setattr(owners, 'addowner', addowner)
+
+# names are in the module now
+populate_owners()
+
+
+class MultiTypeModule(_NameSpace):
+    "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', '_path')
+
+    def __init__(self, setting, prop, opt=None, path=None):
+        self._opt = opt
+        self._path = path
+        self._setting = setting
+        self._properties = prop
+
+    def append(self, propname):
+        if self._opt is not None and self._opt._calc_properties is not None \
+                and propname in self._opt._calc_properties:
+            raise ValueError(_('cannot append {0} property for option {1}: '
+                               'this property is calculated').format(
+                                   propname, self._opt._name))
+        self._properties.add(propname)
+        self._setting._setproperties(self._properties, self._opt, self._path)
+
+    def remove(self, propname):
+        if propname in self._properties:
+            self._properties.remove(propname)
+            self._setting._setproperties(self._properties, self._opt, self._path)
+
+    def reset(self):
+        self._setting.reset(_path=self._path)
+
+    def __contains__(self, propname):
+        return propname in self._properties
+
+    def __repr__(self):
+        return str(list(self._properties))
+
+
+def set_storage(name, **args):
+    storage_type.set_storage(name)
+    settings = __import__(storage_type.get_storage(), globals(), locals(),
+                          ['Setting'], -1).Setting()
+    for option, value in args.items():
+        try:
+            getattr(settings, option)
+            setattr(settings, option, value)
+        except AttributeError:
+            raise ValueError(_('option {0} not already exists in storage {1}'
+                               '').format(option, name))
+
+
+def get_storage(context, session_id, persistent):
+    def gen_id(config):
+        return str(id(config)) + str(time())
+
+    if session_id is None:
+        session_id = gen_id(context)
+    return __import__(storage_type.get_storage(), globals(), locals(),
+                      ['Storage'], -1).Storage(session_id, persistent)
+
+
+def list_sessions():
+    return __import__(storage_type.get_storage(), globals(), locals(),
+                      ['list_sessions'], -1).list_sessions()
+
+
+def delete_session(session_id):
+    return __import__(storage_type.get_storage(), globals(), locals(),
+                      ['delete_session'], -1).delete_session(session_id)
+
+
+#____________________________________________________________
+class Settings(object):
     "``Config()``'s configuration options"
-    # properties attribute: the name of a property enables this property
-    properties = ['hidden', 'disabled']
-    # overrides the validations in the acces of the option values
-    permissive = []
-    # a mandatory option must have a value that is not None
-    mandatory = True
-    frozen = True
-    # enables validation function for options if set
-    validator = False
-    # generic owner. 'default' is the general config owner after init time
-    owner = 'user'
-    # ____________________________________________________________
+    __slots__ = ('context', '_owner', '_p_', '__weakref__')
+
+    def __init__(self, context, storage):
+        """
+        initializer
+
+        :param context: the root config
+        :param storage: the storage type
+
+                        - dictionary -> in memory
+                        - sqlite3 -> persistent
+        """
+        # generic owner
+        self._owner = owners.user
+        self.context = weakref.ref(context)
+        import_lib = 'tiramisu.storage.{0}.setting'.format(storage.storage)
+        self._p_ = __import__(import_lib, globals(), locals(), ['Settings'],
+                              -1).Settings(storage)
+
+    #____________________________________________________________
     # properties methods
-    def has_properties(self):
-        "has properties means the Config's properties attribute is not empty"
-        return bool(len(self.properties))
+    def __contains__(self, propname):
+        "enables the pythonic 'in' syntaxic sugar"
+        return propname in self._getproperties()
+
+    def __repr__(self):
+        return str(list(self._getproperties()))
+
+    def __getitem__(self, opt):
+        path = self._get_opt_path(opt)
+        return self._getitem(opt, path)
+
+    def _getitem(self, opt, path):
+        return Property(self, self._getproperties(opt, path), opt, path)
 
-    def has_property(self, propname):
-        """has property propname in the Config's properties attribute
-        :param property: string wich is the name of the property"""
-        return propname in self.properties
+    def __setitem__(self, opt, value):
+        raise ValueError('you should only append/remove properties')
 
-    def enable_property(self, propname):
+    def reset(self, opt=None, _path=None, all_properties=False):
+        if all_properties and (_path or opt):
+            raise ValueError(_('opt and all_properties must not be set '
+                               'together in reset'))
+        if all_properties:
+            self._p_.reset_all_propertives()
+        else:
+            if opt is not None and _path is None:
+                _path = self._get_opt_path(opt)
+            self._p_.reset_properties(_path)
+        self.context().cfgimpl_reset_cache()
+
+    def _getproperties(self, opt=None, path=None, is_apply_req=True):
+        if opt is None:
+            props = self._p_.getproperties(path, default_properties)
+        else:
+            if path is None:
+                raise ValueError(_('if opt is not None, path should not be'
+                                   ' None in _getproperties'))
+            ntime = None
+            if self._p_.hascache('property', path):
+                ntime = time()
+                is_cached, props = self._p_.getcache('property', path, ntime)
+                if is_cached:
+                    return props
+            props = self._p_.getproperties(path, opt._properties)
+            if is_apply_req:
+                props |= self.apply_requires(opt, path)
+            if 'expire' in self:
+                if ntime is None:
+                    ntime = time()
+                self._p_.setcache('property', path, props, ntime + expires_time)
+        return props
+
+    def append(self, propname):
         "puts property propname in the Config's properties attribute"
-        if propname not in self.properties:
-            self.properties.append(propname)
+        props = self._p_.getproperties(None, default_properties)
+        props.add(propname)
+        self._setproperties(props, None, None)
 
-    def disable_property(self, propname):
+    def remove(self, propname):
         "deletes property propname in the Config's properties attribute"
-        if self.has_property(propname):
-            self.properties.remove(propname)
+        props = self._p_.getproperties(None, default_properties)
+        if propname in props:
+            props.remove(propname)
+            self._setproperties(props, None, None)
+
+    def _setproperties(self, properties, opt, path):
+        """save properties for specified opt
+        (never save properties if same has option properties)
+        """
+        if opt is None:
+            self._p_.setproperties(None, properties)
+        else:
+            if opt._calc_properties is not None:
+                properties -= opt._calc_properties
+            if set(opt._properties) == properties:
+                self._p_.reset_properties(path)
+            else:
+                self._p_.setproperties(path, properties)
+        self.context().cfgimpl_reset_cache()
+
+    #____________________________________________________________
+    def validate_properties(self, opt_or_descr, is_descr, is_write, path,
+                            value=None, force_permissive=False,
+                            force_properties=None):
+        """
+        validation upon the properties related to `opt_or_descr`
+
+        :param opt_or_descr: an option or an option description object
+        :param force_permissive: behaves as if the permissive property
+                                 was present
+        :param is_descr: we have to know if we are in an option description,
+                         just because the mandatory property
+                         doesn't exist here
 
-    def set_permissive(self, permissive):
-        if not isinstance(permissive, list):
-            raise TypeError('permissive must be a list')
-        self.permissive = permissive
+        :param is_write: in the validation process, an option is to be modified,
+                         the behavior can be different
+                         (typically with the `frozen` property)
+        """
+        # opt properties
+        properties = copy(self._getproperties(opt_or_descr, path))
+        # remove opt permissive
+        properties -= self._p_.getpermissive(path)
+        # remove global permissive if need
+        self_properties = copy(self._getproperties())
+        if force_permissive is True or 'permissive' in self_properties:
+            properties -= self._p_.getpermissive()
+
+        # 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()._isempty(
+                        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')
+        # at this point an option should not remain in properties
+        if properties != frozenset():
+            props = list(properties)
+            if 'frozen' in properties:
+                raise PropertiesOptionError(_('cannot change the value for '
+                                              'option {0} this option is'
+                                              ' frozen').format(
+                                                  opt_or_descr._name),
+                                            props)
+            else:
+                raise PropertiesOptionError(_("trying to access to an option "
+                                              "named: {0} with properties {1}"
+                                              "").format(opt_or_descr._name,
+                                                         str(props)), props)
+
+    def setpermissive(self, permissive, path=None):
+        if not isinstance(permissive, tuple):
+            raise TypeError(_('permissive must be a tuple'))
+        self._p_.setpermissive(path, 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.freeze()
-        self.disable_property('hidden')
-        self.enable_property('disabled')
-        self.mandatory = True
-        self.validator = True
+        self._read(ro_remove, ro_append)
 
     def read_write(self):
         "convenience method to freeze, hidde and disable"
-        self.freeze()
-        self.enable_property('hidden')
-        self.enable_property('disabled')
-        self.mandatory = False
-
-    def non_mandatory(self):
-        """mandatory at the Config level means that the Config raises an error
-        if a mandatory option is found"""
-        self.mandatory = False
-
-    def mandatory(self):
-        """mandatory at the Config level means that the Config raises an error
-        if a mandatory option is found"""
-        self.mandatory = True
-
-    def is_mandatory(self):
-        "all mandatory Options shall have a value"
-        return self.mandatory
-
-    def freeze(self):
-        "cannot modify the frozen `Option`'s"
-        self.frozen = True
-
-    def unfreeze(self):
-        "can modify the Options that are frozen"
-        self.frozen = False
-
-    def is_frozen(self):
-        "freeze flag at Config level"
-        return self.frozen
-
-    def set_owner(self, owner):
-        ":param owner: sets the default value for owner at the Config level"
-        self.owner = owner
+        self._read(rw_remove, rw_append)
+
+    def reset_cache(self, only_expired):
+        if only_expired:
+            self._p_.reset_expired_cache('property', time())
+        else:
+            self._p_.reset_all_cache('property')
+
+    def apply_requires(self, opt, path):
+        """carries out the jit (just in time) requirements between options
+
+        a requirement is a tuple of this form that comes from the option's
+        requirements validation::
+
+            (option, expected, action, inverse, transitive, same_action)
+
+        let's have a look at all the tuple's items:
+
+        - **option** is the target option's name or path
+
+        - **expected** is the target option's value that is going to trigger an action
+
+        - **action** is the (property) action to be accomplished if the target option
+          happens to have the expected value
+
+        - if **inverse** is `True` and if the target option's value does not
+          apply, then the property action must be removed from the option's
+          properties list (wich means that the property is inverted)
+
+        - **transitive**: but what happens if the target option cannot be
+          accessed ? We don't kown the target option's value. Actually if some
+          property in the target option is not present in the permissive, the
+          target option's value cannot be accessed. In this case, the
+          **action** have to be applied to the option. (the **action** property
+          is then added to the option).
+
+        - **same_action**: actually, if **same_action** is `True`, the
+          transitivity is not accomplished. The transitivity is accomplished
+          only if the target option **has the same property** that the demanded
+          action. If the target option's value is not accessible because of
+          another reason, because of a property of another type, then an
+          exception :exc:`~error.RequirementError` is raised.
+
+        And at last, if no target option matches the expected values, the
+        action must be removed from the option's properties list.
+
+        :param opt: the option on wich the requirement occurs
+        :type opt: `option.Option()`
+        :param path: the option's path in the config
+        :type path: str
+        """
+        if opt._requires is None:
+            return frozenset()
+
+        # filters the callbacks
+        calc_properties = set()
+        for requires in opt._requires:
+            for require in requires:
+                option, expected, action, inverse, \
+                    transitive, same_action = require
+                reqpath = self._get_opt_path(option)
+                if reqpath == path or reqpath.startswith(path + '.'):
+                    raise RequirementError(_("malformed requirements "
+                                             "imbrication detected for option:"
+                                             " '{0}' with requirement on: "
+                                             "'{1}'").format(path, reqpath))
+                try:
+                    value = self.context()._getattr(reqpath,
+                                                    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,
+                                                                   reqpath,
+                                                                   properties))
+                    # transitive action, force expected
+                    value = expected[0]
+                    inverse = False
+                if (not inverse and
+                        value in expected or
+                        inverse and value not in expected):
+                    calc_properties.add(action)
+                    # the calculation cannot be carried out
+                    break
+            return calc_properties
 
-# Setting is actually a singleton
-settings = Setting()
+    def _get_opt_path(self, opt):
+        return self.context().cfgimpl_get_description().impl_get_path_by_opt(opt)