Source code for aiida.orm.entities

# -*- coding: utf-8 -*-
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# Copyright (c), The AiiDA team. All rights reserved.                     #
# This file is part of the AiiDA code.                                    #
#                                                                         #
# The code is hosted on GitHub at https://github.com/aiidateam/aiida-core #
# For further information on the license, see the LICENSE.txt file        #
# For further information please visit http://www.aiida.net               #
###########################################################################
"""Module for all common top level AiiDA entity classes and methods"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import typing

from plumpy.base.utils import super_check, call_with_super_check

from aiida.common import exceptions
from aiida.common import datastructures
from aiida.common.lang import classproperty, type_check
from aiida.manage.manager import get_manager

__all__ = ('Entity', 'Collection')

EntityType = typing.TypeVar('EntityType')  # pylint: disable=invalid-name


[docs]class Collection(typing.Generic[EntityType]): # pylint: disable=unsubscriptable-object """Container class that represents the collection of objects of a particular type.""" # A store for any backend specific collections that already exist _COLLECTIONS = datastructures.LazyStore()
[docs] @classmethod def get_collection(cls, entity_type, backend): """ Get the collection for a given entity type and backend instance :param entity_type: the entity type e.g. User, Computer, etc :type entity_type: :class:`aiida.orm.Entity` :param backend: the backend instance to get the collection for :type backend: :class:`aiida.orm.implementation.Backend` :return: a new collection with the new backend :rtype: :class:`aiida.orm.Collection` """ # Lazily get the collection i.e. create only if we haven't done so yet return cls._COLLECTIONS.get((entity_type, backend), lambda: entity_type.Collection(backend, entity_type))
[docs] def __init__(self, backend, entity_class): """ Construct a new entity collection. :param backend: the backend instance to get the collection for :type backend: :class:`aiida.orm.implementation.Backend` :param entity_class: the entity type e.g. User, Computer, etc :type entity_class: :class:`aiida.orm.Entity` """ assert issubclass(entity_class, Entity), 'Must provide an entity type' self._backend = backend or get_manager().get_backend() self._entity_type = entity_class
[docs] def __call__(self, backend): """ Create a new objects collection using a new backend. :param backend: the backend instance to get the collection for :type backend: :class:`aiida.orm.implementation.Backend` :return: a new collection with the new backend :rtype: :class:`aiida.orm.Collection` """ if backend is self._backend: # Special case if they actually want the same collection return self return self.get_collection(self.entity_type, backend)
@property def backend(self): """Return the backend. :return: the backend instance of this collection :rtype: :class:`aiida.orm.implementation.Backend` """ return self._backend @property def entity_type(self): """The entity type. :rtype: :class:`aiida.orm.Entity` """ return self._entity_type
[docs] def query(self): """ Get a query builder for the objects of this collection :return: a new query builder instance :rtype: :class:`aiida.orm.QueryBuilder` """ # pylint: disable=no-self-use from . import querybuilder query = querybuilder.QueryBuilder() query.append(self._entity_type, project='*') return query
[docs] def get(self, **filters): """ Get a single collection entry that matches the filter criteria :param filters: the filters identifying the object to get :type filters: dict :return: the entry """ res = self.find(filters=filters) if not res: raise exceptions.NotExistent("No {} with filter '{}' found".format(self.entity_type.__name__, filters)) if len(res) > 1: raise exceptions.MultipleObjectsError( "Multiple {}s found with the same id '{}'".format(self.entity_type.__name__, id) ) return res[0]
[docs] def find(self, filters=None, order_by=None, limit=None): """ Find collection entries matching the filter criteria :param filters: the keyword value pair filters to match :type filters: dict :param order_by: a list of (key, direction) pairs specifying the sort order :type order_by: list :param limit: the maximum number of results to return :type limit: int :return: a list of resulting matches :rtype: list """ query = self.query() filters = filters or {} query.add_filter(self.entity_type, filters) if order_by: query.order_by({self.entity_type: order_by}) if limit: query.limit(limit) return [_[0] for _ in query.all()]
[docs] def all(self): """ Get all entities in this collection :return: A collection of users matching the criteria :rtype: list """ return [_[0] for _ in self.query().all()]
[docs]class Entity(object): """An AiiDA entity""" _objects = None # Define our collection type Collection = Collection
[docs] @classproperty def objects(cls, backend=None): # pylint: disable=no-self-use, no-self-argument """ Get a collection for objects of this type. :param backend: the optional backend to use (otherwise use default) :type backend: :class:`aiida.orm.implementation.Backend` :return: an object that can be used to access entities of this type :rtype: :class:`aiida.orm.Collection` """ backend = backend or get_manager().get_backend() return cls.Collection.get_collection(cls, backend)
[docs] @classmethod def get(cls, **kwargs): # pylint: disable=redefined-builtin, invalid-name return cls.objects.get(**kwargs) # pylint: disable=no-member
[docs] @classmethod def from_backend_entity(cls, backend_entity): """ Construct an entity from a backend entity instance :param backend_entity: the backend entity :return: an AiiDA entity instance """ from . import implementation type_check(backend_entity, implementation.BackendEntity) entity = cls.__new__(cls) entity.init_from_backend(backend_entity) call_with_super_check(entity.initialize) return entity
[docs] def __init__(self, backend_entity): """ :param backend_entity: the backend model supporting this entity :type backend_entity: :class:`aiida.orm.implementation.BackendEntity` """ self._backend_entity = backend_entity call_with_super_check(self.initialize)
[docs] def init_from_backend(self, backend_entity): """ :param backend_entity: the backend model supporting this entity :type backend_entity: :class:`aiida.orm.implementation.BackendEntity` """ self._backend_entity = backend_entity
@super_check def initialize(self): """Initialize instance attributes. This will be called after the constructor is called or an entity is created from an existing backend entity. """ @property def id(self): """Return the id for this entity. This identifier is guaranteed to be unique amongst entities of the same type for a single backend instance. :return: the entity's id """ # pylint: disable=redefined-builtin, invalid-name return self._backend_entity.id @property def pk(self): """Return the primary key for this entity. This identifier is guaranteed to be unique amongst entities of the same type for a single backend instance. :return: the entity's principal key """ return self.id @property def uuid(self): """Return the UUID for this entity. This identifier is unique across all entities types and backend instances. :return: the entity uuid :rtype: :class:`uuid.UUID` """ return self._backend_entity.uuid
[docs] def store(self): """Store the entity.""" self._backend_entity.store() return self
@property def is_stored(self): """Return whether the entity is stored. :return: boolean, True if stored, False otherwise :rtype: bool """ return self._backend_entity.is_stored @property def backend(self): """ Get the backend for this entity :return: the backend instance """ return self._backend_entity.backend @property def backend_entity(self): """ Get the implementing class for this object :return: the class model """ return self._backend_entity