Github user mxmrlv commented on a diff in the pull request:
https://github.com/apache/incubator-ariatosca/pull/31#discussion_r90778979
--- Diff: aria/storage/structures.py ---
@@ -27,281 +27,189 @@
* Model - abstract model implementation.
"""
import json
-from itertools import count
-from uuid import uuid4
-
-from .exceptions import StorageError
-from ..logger import LoggerMixin
-from ..utils.validation import ValidatorMixin
-
-__all__ = (
- 'uuid_generator',
- 'Field',
- 'IterField',
- 'PointerField',
- 'IterPointerField',
- 'Model',
- 'Storage',
+
+from sqlalchemy import VARCHAR
+from sqlalchemy.ext.mutable import Mutable
+from sqlalchemy.orm import relationship, backref
+from sqlalchemy.ext.declarative import declarative_base
+# pylint: disable=unused-import
+from sqlalchemy.ext.associationproxy import association_proxy
+from sqlalchemy import (
+ schema,
+ Column,
+ Integer,
+ Text,
+ DateTime,
+ Boolean,
+ Enum,
+ String,
+ PickleType,
+ Float,
+ TypeDecorator,
+ ForeignKey,
+ orm,
)
+Model = declarative_base()
-def uuid_generator():
- """
- wrapper function which generates ids
- """
- return str(uuid4())
+def foreign_key(foreign_key_column, nullable=False):
+ """Return a ForeignKey object with the relevant
-class Field(ValidatorMixin):
+ :param foreign_key_column: Unique id column in the parent table
+ :param nullable: Should the column be allowed to remain empty
"""
- A single field implementation
+ return Column(
+ ForeignKey(foreign_key_column, ondelete='CASCADE'),
+ nullable=nullable
+ )
+
+
+def one_to_many_relationship(child_class,
+ parent_class,
+ foreign_key_column,
+ backreference=None):
+ """Return a one-to-many SQL relationship object
+ Meant to be used from inside the *child* object
+
+ :param parent_class: Class of the parent table
+ :param child_class: Class of the child table
+ :param foreign_key_column: The column of the foreign key
+ :param backreference: The name to give to the reference to the child
"""
- NO_DEFAULT = 'NO_DEFAULT'
-
- try:
- # python 3 syntax
- _next_id = count().__next__
- except AttributeError:
- # python 2 syntax
- _next_id = count().next
- _ATTRIBUTE_NAME = '_cache_{0}'.format
-
- def __init__(
- self,
- type=None,
- choices=(),
- validation_func=None,
- default=NO_DEFAULT,
- **kwargs):
- """
- Simple field manager.
-
- :param type: possible type of the field.
- :param choices: a set of possible field values.
- :param default: default field value.
- :param kwargs: kwargs to be passed to next in line classes.
- """
- self.type = type
- self.choices = choices
- self.default = default
- self.validation_func = validation_func
- super(Field, self).__init__(**kwargs)
-
- def __get__(self, instance, owner):
- if instance is None:
- return self
- field_name = self._field_name(instance)
- try:
- return getattr(instance, self._ATTRIBUTE_NAME(field_name))
- except AttributeError as exc:
- if self.default == self.NO_DEFAULT:
- raise AttributeError(
- str(exc).replace(self._ATTRIBUTE_NAME(field_name),
field_name))
-
- default_value = self.default() if callable(self.default) else
self.default
- setattr(instance, self._ATTRIBUTE_NAME(field_name), default_value)
- return default_value
-
- def __set__(self, instance, value):
- field_name = self._field_name(instance)
- self.validate_value(field_name, value, instance)
- setattr(instance, self._ATTRIBUTE_NAME(field_name), value)
-
- def validate_value(self, name, value, instance):
- """
- Validates the value of the field.
-
- :param name: the name of the field.
- :param value: the value of the field.
- :param instance: the instance containing the field.
- """
- if self.default != self.NO_DEFAULT and value == self.default:
- return
- if self.type:
- self.validate_instance(name, value, self.type)
- if self.choices:
- self.validate_in_choice(name, value, self.choices)
- if self.validation_func:
- self.validation_func(name, value, instance)
-
- def _field_name(self, instance):
- """
- retrieves the field name from the instance.
-
- :param Field instance: the instance which holds the field.
- :return: name of the field
- :rtype: basestring
- """
- for name, member in vars(instance.__class__).iteritems():
- if member is self:
- return name
+ backreference = backreference or child_class.__tablename__
+ return relationship(
+ parent_class,
+ primaryjoin=lambda: parent_class.storage_id == foreign_key_column,
+ # The following line make sure that when the *parent* is
+ # deleted, all its connected children are deleted as well
+ backref=backref(backreference, cascade='all')
+ )
-class IterField(Field):
+class Dict(TypeDecorator):
"""
- Represents an iterable field.
+ Dict representation of type.
"""
- def __init__(self, **kwargs):
- """
- Simple iterable field manager.
- This field type don't have choices option.
- :param kwargs: kwargs to be passed to next in line classes.
- """
- super(IterField, self).__init__(choices=(), **kwargs)
+ def process_literal_param(self, value, dialect):
+ pass
- def validate_value(self, name, values, *args):
- """
- Validates the value of each iterable value.
+ @property
+ def python_type(self):
+ return dict
- :param name: the name of the field.
- :param values: the values of the field.
- """
- for value in values:
- self.validate_instance(name, value, self.type)
+ impl = VARCHAR
+ def process_bind_param(self, value, dialect):
+ if value is not None:
+ value = json.dumps(value)
+ return value
-class PointerField(Field):
- """
- A single pointer field implementation.
+ def process_result_value(self, value, dialect):
+ if value is not None:
+ value = json.loads(value)
+ return value
- Any PointerField points via id to another document.
+
+class MutableDict(Mutable, dict):
+ """
+ Enables tracking for dict values.
"""
+ @classmethod
+ def coerce(cls, key, value):
+ "Convert plain dictionaries to MutableDict."
- def __init__(self, type, **kwargs):
- assert issubclass(type, Model)
- super(PointerField, self).__init__(type=type, **kwargs)
+ if not isinstance(value, MutableDict):
+ if isinstance(value, dict):
+ return MutableDict(value)
+ # this call will raise ValueError
+ return Mutable.coerce(key, value)
+ else:
+ return value
-class IterPointerField(IterField, PointerField):
- """
- An iterable pointers field.
+ def __setitem__(self, key, value):
+ "Detect dictionary set events and emit change events."
- Any IterPointerField points via id to other documents.
- """
- pass
+ dict.__setitem__(self, key, value)
+ self.changed()
+ def __delitem__(self, key):
+ "Detect dictionary del events and emit change events."
-class Model(object):
- """
- Base class for all of the storage models.
- """
- id = None
+ dict.__delitem__(self, key)
+ self.changed()
- def __init__(self, **fields):
- """
- Abstract class for any model in the storage.
- The Initializer creates attributes according to the (keyword
arguments) that given
- Each value is validated according to the Field.
- Each model has to have and ID Field.
- :param fields: each item is validated and transformed into
instance attributes.
- """
- self._assert_model_have_id_field(**fields)
- missing_fields, unexpected_fields = self._setup_fields(fields)
+class SQLModelBase(Model):
+ """
+ Abstract base class for all SQL models that allows [de]serialization
+ """
+ # SQLAlchemy syntax
+ __abstract__ = True
- if missing_fields:
- raise StorageError(
- 'Model {name} got missing keyword arguments:
{fields}'.format(
- name=self.__class__.__name__, fields=missing_fields))
+ # Does the class represent a resource (Blueprint, Deployment, etc.) or
a
+ # management table (User, Tenant, etc.), as they are handled
differently
+ is_resource = False
--- End diff --
remove
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