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Diffstat (limited to 'azure/aria/aria-extension-cloudify/src/aria/aria/modeling/types.py')
| -rw-r--r-- | azure/aria/aria-extension-cloudify/src/aria/aria/modeling/types.py | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/azure/aria/aria-extension-cloudify/src/aria/aria/modeling/types.py b/azure/aria/aria-extension-cloudify/src/aria/aria/modeling/types.py new file mode 100644 index 0000000..38240fa --- /dev/null +++ b/azure/aria/aria-extension-cloudify/src/aria/aria/modeling/types.py @@ -0,0 +1,318 @@ +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +""" +Allows JSON-serializable collections to be used as SQLAlchemy column types. +""" + +import json +from collections import namedtuple + +from sqlalchemy import ( + TypeDecorator, + VARCHAR, + event +) +from sqlalchemy.ext import mutable +from ruamel import yaml + +from . import exceptions + + +class _MutableType(TypeDecorator): + """ + Dict representation of type. + """ + @property + def python_type(self): + raise NotImplementedError + + def process_literal_param(self, value, dialect): + pass + + impl = VARCHAR + + def process_bind_param(self, value, dialect): + if value is not None: + value = json.dumps(value) + return value + + def process_result_value(self, value, dialect): + if value is not None: + value = json.loads(value) + return value + + +class Dict(_MutableType): + """ + JSON-serializable dict type for SQLAlchemy columns. + """ + @property + def python_type(self): + return dict + + +class List(_MutableType): + """ + JSON-serializable list type for SQLAlchemy columns. + """ + @property + def python_type(self): + return list + + +class _StrictDictMixin(object): + + @classmethod + def coerce(cls, key, value): + """ + Convert plain dictionaries to MutableDict. + """ + try: + if not isinstance(value, cls): + if isinstance(value, dict): + for k, v in value.items(): + cls._assert_strict_key(k) + cls._assert_strict_value(v) + return cls(value) + return mutable.MutableDict.coerce(key, value) + else: + return value + except ValueError as e: + raise exceptions.ValueFormatException('could not coerce to MutableDict', cause=e) + + def __setitem__(self, key, value): + self._assert_strict_key(key) + self._assert_strict_value(value) + super(_StrictDictMixin, self).__setitem__(key, value) + + def setdefault(self, key, value): + self._assert_strict_key(key) + self._assert_strict_value(value) + super(_StrictDictMixin, self).setdefault(key, value) + + def update(self, *args, **kwargs): + for k, v in kwargs.items(): + self._assert_strict_key(k) + self._assert_strict_value(v) + super(_StrictDictMixin, self).update(*args, **kwargs) + + @classmethod + def _assert_strict_key(cls, key): + if cls._key_cls is not None and not isinstance(key, cls._key_cls): + raise exceptions.ValueFormatException('key type was set strictly to {0}, but was {1}' + .format(cls._key_cls, type(key))) + + @classmethod + def _assert_strict_value(cls, value): + if cls._value_cls is not None and not isinstance(value, cls._value_cls): + raise exceptions.ValueFormatException('value type was set strictly to {0}, but was {1}' + .format(cls._value_cls, type(value))) + + +class _MutableDict(mutable.MutableDict): + """ + Enables tracking for dict values. + """ + + @classmethod + def coerce(cls, key, value): + """ + Convert plain dictionaries to MutableDict. + """ + try: + return mutable.MutableDict.coerce(key, value) + except ValueError as e: + raise exceptions.ValueFormatException('could not coerce value', cause=e) + + +class _StrictListMixin(object): + + @classmethod + def coerce(cls, key, value): + "Convert plain dictionaries to MutableDict." + try: + if not isinstance(value, cls): + if isinstance(value, list): + for item in value: + cls._assert_item(item) + return cls(value) + return mutable.MutableList.coerce(key, value) + else: + return value + except ValueError as e: + raise exceptions.ValueFormatException('could not coerce to MutableDict', cause=e) + + def __setitem__(self, index, value): + """ + Detect list set events and emit change events. + """ + self._assert_item(value) + super(_StrictListMixin, self).__setitem__(index, value) + + def append(self, item): + self._assert_item(item) + super(_StrictListMixin, self).append(item) + + def extend(self, item): + self._assert_item(item) + super(_StrictListMixin, self).extend(item) + + def insert(self, index, item): + self._assert_item(item) + super(_StrictListMixin, self).insert(index, item) + + @classmethod + def _assert_item(cls, item): + if cls._item_cls is not None and not isinstance(item, cls._item_cls): + raise exceptions.ValueFormatException('key type was set strictly to {0}, but was {1}' + .format(cls._item_cls, type(item))) + + +class _MutableList(mutable.MutableList): + + @classmethod + def coerce(cls, key, value): + """ + Convert plain dictionaries to MutableDict. + """ + try: + return mutable.MutableList.coerce(key, value) + except ValueError as e: + raise exceptions.ValueFormatException('could not coerce to MutableDict', cause=e) + + +_StrictDictID = namedtuple('_StrictDictID', 'key_cls, value_cls') +_StrictValue = namedtuple('_StrictValue', 'type_cls, listener_cls') + +class _StrictDict(object): + """ + This entire class functions as a factory for strict dicts and their listeners. No type class, + and no listener type class is created more than once. If a relevant type class exists it is + returned. + """ + _strict_map = {} + + def __call__(self, key_cls=None, value_cls=None): + strict_dict_map_key = _StrictDictID(key_cls=key_cls, value_cls=value_cls) + if strict_dict_map_key not in self._strict_map: + key_cls_name = getattr(key_cls, '__name__', str(key_cls)) + value_cls_name = getattr(value_cls, '__name__', str(value_cls)) + # Creating the type class itself. this class would be returned (used by the SQLAlchemy + # Column). + strict_dict_cls = type( + 'StrictDict_{0}_{1}'.format(key_cls_name, value_cls_name), + (Dict, ), + {} + ) + # Creating the type listening class. + # The new class inherits from both the _MutableDict class and the _StrictDictMixin, + # while setting the necessary _key_cls and _value_cls as class attributes. + listener_cls = type( + 'StrictMutableDict_{0}_{1}'.format(key_cls_name, value_cls_name), + (_StrictDictMixin, _MutableDict), + {'_key_cls': key_cls, '_value_cls': value_cls} + ) + yaml.representer.RoundTripRepresenter.add_representer( + listener_cls, yaml.representer.RoundTripRepresenter.represent_list) + self._strict_map[strict_dict_map_key] = _StrictValue(type_cls=strict_dict_cls, + listener_cls=listener_cls) + + return self._strict_map[strict_dict_map_key].type_cls + + +StrictDict = _StrictDict() +""" +JSON-serializable strict dict type for SQLAlchemy columns. + +:param key_cls: +:param value_cls: +""" + + +class _StrictList(object): + """ + This entire class functions as a factory for strict lists and their listeners. No type class, + and no listener type class is created more than once. If a relevant type class exists it is + returned. + """ + _strict_map = {} + + def __call__(self, item_cls=None): + + if item_cls not in self._strict_map: + item_cls_name = getattr(item_cls, '__name__', str(item_cls)) + # Creating the type class itself. this class would be returned (used by the SQLAlchemy + # Column). + strict_list_cls = type( + 'StrictList_{0}'.format(item_cls_name), + (List, ), + {} + ) + # Creating the type listening class. + # The new class inherits from both the _MutableList class and the _StrictListMixin, + # while setting the necessary _item_cls as class attribute. + listener_cls = type( + 'StrictMutableList_{0}'.format(item_cls_name), + (_StrictListMixin, _MutableList), + {'_item_cls': item_cls} + ) + yaml.representer.RoundTripRepresenter.add_representer( + listener_cls, yaml.representer.RoundTripRepresenter.represent_list) + self._strict_map[item_cls] = _StrictValue(type_cls=strict_list_cls, + listener_cls=listener_cls) + + return self._strict_map[item_cls].type_cls + + +StrictList = _StrictList() +""" +JSON-serializable strict list type for SQLAlchemy columns. + +:param item_cls: +""" + + +def _mutable_association_listener(mapper, cls): + strict_dict_type_to_listener = \ + dict((v.type_cls, v.listener_cls) for v in _StrictDict._strict_map.itervalues()) + + strict_list_type_to_listener = \ + dict((v.type_cls, v.listener_cls) for v in _StrictList._strict_map.itervalues()) + + for prop in mapper.column_attrs: + column_type = prop.columns[0].type + # Dict Listeners + if type(column_type) in strict_dict_type_to_listener: # pylint: disable=unidiomatic-typecheck + strict_dict_type_to_listener[type(column_type)].associate_with_attribute( + getattr(cls, prop.key)) + elif isinstance(column_type, Dict): + _MutableDict.associate_with_attribute(getattr(cls, prop.key)) + + # List Listeners + if type(column_type) in strict_list_type_to_listener: # pylint: disable=unidiomatic-typecheck + strict_list_type_to_listener[type(column_type)].associate_with_attribute( + getattr(cls, prop.key)) + elif isinstance(column_type, List): + _MutableList.associate_with_attribute(getattr(cls, prop.key)) + + +_LISTENER_ARGS = (mutable.mapper, 'mapper_configured', _mutable_association_listener) + + +def _register_mutable_association_listener(): + event.listen(*_LISTENER_ARGS) + +_register_mutable_association_listener() |