--- /dev/null
+# 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()
Code Review / multicloud / azure.git / blobdiff