467 lines
18 KiB
Python
467 lines
18 KiB
Python
import itertools
|
|
import warnings
|
|
|
|
from mongoengine.base.common import _document_registry
|
|
from mongoengine.base.fields import BaseField, ComplexBaseField, ObjectIdField
|
|
from mongoengine.common import _import_class
|
|
from mongoengine.errors import InvalidDocumentError
|
|
from mongoengine.queryset import (
|
|
DO_NOTHING,
|
|
DoesNotExist,
|
|
MultipleObjectsReturned,
|
|
QuerySetManager,
|
|
)
|
|
|
|
|
|
__all__ = ("DocumentMetaclass", "TopLevelDocumentMetaclass")
|
|
|
|
|
|
class DocumentMetaclass(type):
|
|
"""Metaclass for all documents."""
|
|
|
|
# TODO lower complexity of this method
|
|
def __new__(mcs, name, bases, attrs):
|
|
flattened_bases = mcs._get_bases(bases)
|
|
super_new = super().__new__
|
|
|
|
# If a base class just call super
|
|
metaclass = attrs.get("my_metaclass")
|
|
if metaclass and issubclass(metaclass, DocumentMetaclass):
|
|
return super_new(mcs, name, bases, attrs)
|
|
|
|
attrs["_is_document"] = attrs.get("_is_document", False)
|
|
attrs["_cached_reference_fields"] = []
|
|
|
|
# EmbeddedDocuments could have meta data for inheritance
|
|
if "meta" in attrs:
|
|
attrs["_meta"] = attrs.pop("meta")
|
|
|
|
# EmbeddedDocuments should inherit meta data
|
|
if "_meta" not in attrs:
|
|
meta = MetaDict()
|
|
for base in flattened_bases[::-1]:
|
|
# Add any mixin metadata from plain objects
|
|
if hasattr(base, "meta"):
|
|
meta.merge(base.meta)
|
|
elif hasattr(base, "_meta"):
|
|
meta.merge(base._meta)
|
|
attrs["_meta"] = meta
|
|
attrs["_meta"][
|
|
"abstract"
|
|
] = False # 789: EmbeddedDocument shouldn't inherit abstract
|
|
|
|
# If allow_inheritance is True, add a "_cls" string field to the attrs
|
|
if attrs["_meta"].get("allow_inheritance"):
|
|
StringField = _import_class("StringField")
|
|
attrs["_cls"] = StringField()
|
|
|
|
# Handle document Fields
|
|
|
|
# Merge all fields from subclasses
|
|
doc_fields = {}
|
|
for base in flattened_bases[::-1]:
|
|
if hasattr(base, "_fields"):
|
|
doc_fields.update(base._fields)
|
|
|
|
# Standard object mixin - merge in any Fields
|
|
if not hasattr(base, "_meta"):
|
|
base_fields = {}
|
|
for attr_name, attr_value in base.__dict__.items():
|
|
if not isinstance(attr_value, BaseField):
|
|
continue
|
|
attr_value.name = attr_name
|
|
if not attr_value.db_field:
|
|
attr_value.db_field = attr_name
|
|
base_fields[attr_name] = attr_value
|
|
|
|
doc_fields.update(base_fields)
|
|
|
|
# Discover any document fields
|
|
field_names = {}
|
|
for attr_name, attr_value in attrs.items():
|
|
if not isinstance(attr_value, BaseField):
|
|
continue
|
|
attr_value.name = attr_name
|
|
if not attr_value.db_field:
|
|
attr_value.db_field = attr_name
|
|
doc_fields[attr_name] = attr_value
|
|
|
|
# Count names to ensure no db_field redefinitions
|
|
field_names[attr_value.db_field] = (
|
|
field_names.get(attr_value.db_field, 0) + 1
|
|
)
|
|
|
|
# Ensure no duplicate db_fields
|
|
duplicate_db_fields = [k for k, v in field_names.items() if v > 1]
|
|
if duplicate_db_fields:
|
|
msg = "Multiple db_fields defined for: %s " % ", ".join(duplicate_db_fields)
|
|
raise InvalidDocumentError(msg)
|
|
|
|
# Set _fields and db_field maps
|
|
attrs["_fields"] = doc_fields
|
|
attrs["_db_field_map"] = {
|
|
k: getattr(v, "db_field", k) for k, v in doc_fields.items()
|
|
}
|
|
attrs["_reverse_db_field_map"] = {
|
|
v: k for k, v in attrs["_db_field_map"].items()
|
|
}
|
|
|
|
attrs["_fields_ordered"] = tuple(
|
|
i[1]
|
|
for i in sorted((v.creation_counter, v.name) for v in doc_fields.values())
|
|
)
|
|
|
|
#
|
|
# Set document hierarchy
|
|
#
|
|
superclasses = ()
|
|
class_name = [name]
|
|
for base in flattened_bases:
|
|
if not getattr(base, "_is_base_cls", True) and not getattr(
|
|
base, "_meta", {}
|
|
).get("abstract", True):
|
|
# Collate hierarchy for _cls and _subclasses
|
|
class_name.append(base.__name__)
|
|
|
|
if hasattr(base, "_meta"):
|
|
# Warn if allow_inheritance isn't set and prevent
|
|
# inheritance of classes where inheritance is set to False
|
|
allow_inheritance = base._meta.get("allow_inheritance")
|
|
if not allow_inheritance and not base._meta.get("abstract"):
|
|
raise ValueError(
|
|
"Document %s may not be subclassed. "
|
|
'To enable inheritance, use the "allow_inheritance" meta attribute.'
|
|
% base.__name__
|
|
)
|
|
|
|
# Get superclasses from last base superclass
|
|
document_bases = [b for b in flattened_bases if hasattr(b, "_class_name")]
|
|
if document_bases:
|
|
superclasses = document_bases[0]._superclasses
|
|
superclasses += (document_bases[0]._class_name,)
|
|
|
|
_cls = ".".join(reversed(class_name))
|
|
attrs["_class_name"] = _cls
|
|
attrs["_superclasses"] = superclasses
|
|
attrs["_subclasses"] = (_cls,)
|
|
attrs["_types"] = attrs["_subclasses"] # TODO depreciate _types
|
|
|
|
# Create the new_class
|
|
new_class = super_new(mcs, name, bases, attrs)
|
|
|
|
# Set _subclasses
|
|
for base in document_bases:
|
|
if _cls not in base._subclasses:
|
|
base._subclasses += (_cls,)
|
|
base._types = base._subclasses # TODO depreciate _types
|
|
|
|
(
|
|
Document,
|
|
EmbeddedDocument,
|
|
DictField,
|
|
CachedReferenceField,
|
|
) = mcs._import_classes()
|
|
|
|
if issubclass(new_class, Document):
|
|
new_class._collection = None
|
|
|
|
# Add class to the _document_registry
|
|
_document_registry[new_class._class_name] = new_class
|
|
|
|
# Handle delete rules
|
|
for field in new_class._fields.values():
|
|
f = field
|
|
if f.owner_document is None:
|
|
f.owner_document = new_class
|
|
delete_rule = getattr(f, "reverse_delete_rule", DO_NOTHING)
|
|
if isinstance(f, CachedReferenceField):
|
|
|
|
if issubclass(new_class, EmbeddedDocument):
|
|
raise InvalidDocumentError(
|
|
"CachedReferenceFields is not allowed in EmbeddedDocuments"
|
|
)
|
|
|
|
if f.auto_sync:
|
|
f.start_listener()
|
|
|
|
f.document_type._cached_reference_fields.append(f)
|
|
|
|
if isinstance(f, ComplexBaseField) and hasattr(f, "field"):
|
|
delete_rule = getattr(f.field, "reverse_delete_rule", DO_NOTHING)
|
|
if isinstance(f, DictField) and delete_rule != DO_NOTHING:
|
|
msg = (
|
|
"Reverse delete rules are not supported "
|
|
"for %s (field: %s)" % (field.__class__.__name__, field.name)
|
|
)
|
|
raise InvalidDocumentError(msg)
|
|
|
|
f = field.field
|
|
|
|
if delete_rule != DO_NOTHING:
|
|
if issubclass(new_class, EmbeddedDocument):
|
|
msg = (
|
|
"Reverse delete rules are not supported for "
|
|
"EmbeddedDocuments (field: %s)" % field.name
|
|
)
|
|
raise InvalidDocumentError(msg)
|
|
f.document_type.register_delete_rule(new_class, field.name, delete_rule)
|
|
|
|
if (
|
|
field.name
|
|
and hasattr(Document, field.name)
|
|
and EmbeddedDocument not in new_class.mro()
|
|
):
|
|
msg = "%s is a document method and not a valid field name" % field.name
|
|
raise InvalidDocumentError(msg)
|
|
|
|
return new_class
|
|
|
|
@classmethod
|
|
def _get_bases(mcs, bases):
|
|
if isinstance(bases, BasesTuple):
|
|
return bases
|
|
seen = []
|
|
bases = mcs.__get_bases(bases)
|
|
unique_bases = (b for b in bases if not (b in seen or seen.append(b)))
|
|
return BasesTuple(unique_bases)
|
|
|
|
@classmethod
|
|
def __get_bases(mcs, bases):
|
|
for base in bases:
|
|
if base is object:
|
|
continue
|
|
yield base
|
|
yield from mcs.__get_bases(base.__bases__)
|
|
|
|
@classmethod
|
|
def _import_classes(mcs):
|
|
Document = _import_class("Document")
|
|
EmbeddedDocument = _import_class("EmbeddedDocument")
|
|
DictField = _import_class("DictField")
|
|
CachedReferenceField = _import_class("CachedReferenceField")
|
|
return Document, EmbeddedDocument, DictField, CachedReferenceField
|
|
|
|
|
|
class TopLevelDocumentMetaclass(DocumentMetaclass):
|
|
"""Metaclass for top-level documents (i.e. documents that have their own
|
|
collection in the database.
|
|
"""
|
|
|
|
def __new__(mcs, name, bases, attrs):
|
|
flattened_bases = mcs._get_bases(bases)
|
|
super_new = super().__new__
|
|
|
|
# Set default _meta data if base class, otherwise get user defined meta
|
|
if attrs.get("my_metaclass") == TopLevelDocumentMetaclass:
|
|
# defaults
|
|
attrs["_meta"] = {
|
|
"abstract": True,
|
|
"max_documents": None,
|
|
"max_size": None,
|
|
"ordering": [], # default ordering applied at runtime
|
|
"indexes": [], # indexes to be ensured at runtime
|
|
"id_field": None,
|
|
"index_background": False,
|
|
"index_opts": None,
|
|
"delete_rules": None,
|
|
# allow_inheritance can be True, False, and None. True means
|
|
# "allow inheritance", False means "don't allow inheritance",
|
|
# None means "do whatever your parent does, or don't allow
|
|
# inheritance if you're a top-level class".
|
|
"allow_inheritance": None,
|
|
}
|
|
attrs["_is_base_cls"] = True
|
|
attrs["_meta"].update(attrs.get("meta", {}))
|
|
else:
|
|
attrs["_meta"] = attrs.get("meta", {})
|
|
# Explicitly set abstract to false unless set
|
|
attrs["_meta"]["abstract"] = attrs["_meta"].get("abstract", False)
|
|
attrs["_is_base_cls"] = False
|
|
|
|
# Set flag marking as document class - as opposed to an object mixin
|
|
attrs["_is_document"] = True
|
|
|
|
# Ensure queryset_class is inherited
|
|
if "objects" in attrs:
|
|
manager = attrs["objects"]
|
|
if hasattr(manager, "queryset_class"):
|
|
attrs["_meta"]["queryset_class"] = manager.queryset_class
|
|
|
|
# Clean up top level meta
|
|
if "meta" in attrs:
|
|
del attrs["meta"]
|
|
|
|
# Find the parent document class
|
|
parent_doc_cls = [
|
|
b for b in flattened_bases if b.__class__ == TopLevelDocumentMetaclass
|
|
]
|
|
parent_doc_cls = None if not parent_doc_cls else parent_doc_cls[0]
|
|
|
|
# Prevent classes setting collection different to their parents
|
|
# If parent wasn't an abstract class
|
|
if (
|
|
parent_doc_cls
|
|
and "collection" in attrs.get("_meta", {})
|
|
and not parent_doc_cls._meta.get("abstract", True)
|
|
):
|
|
msg = "Trying to set a collection on a subclass (%s)" % name
|
|
warnings.warn(msg, SyntaxWarning)
|
|
del attrs["_meta"]["collection"]
|
|
|
|
# Ensure abstract documents have abstract bases
|
|
if attrs.get("_is_base_cls") or attrs["_meta"].get("abstract"):
|
|
if parent_doc_cls and not parent_doc_cls._meta.get("abstract", False):
|
|
msg = "Abstract document cannot have non-abstract base"
|
|
raise ValueError(msg)
|
|
return super_new(mcs, name, bases, attrs)
|
|
|
|
# Merge base class metas.
|
|
# Uses a special MetaDict that handles various merging rules
|
|
meta = MetaDict()
|
|
for base in flattened_bases[::-1]:
|
|
# Add any mixin metadata from plain objects
|
|
if hasattr(base, "meta"):
|
|
meta.merge(base.meta)
|
|
elif hasattr(base, "_meta"):
|
|
meta.merge(base._meta)
|
|
|
|
# Set collection in the meta if its callable
|
|
if getattr(base, "_is_document", False) and not base._meta.get("abstract"):
|
|
collection = meta.get("collection", None)
|
|
if callable(collection):
|
|
meta["collection"] = collection(base)
|
|
|
|
meta.merge(attrs.get("_meta", {})) # Top level meta
|
|
|
|
# Only simple classes (i.e. direct subclasses of Document) may set
|
|
# allow_inheritance to False. If the base Document allows inheritance,
|
|
# none of its subclasses can override allow_inheritance to False.
|
|
simple_class = all(
|
|
[b._meta.get("abstract") for b in flattened_bases if hasattr(b, "_meta")]
|
|
)
|
|
if (
|
|
not simple_class
|
|
and meta["allow_inheritance"] is False
|
|
and not meta["abstract"]
|
|
):
|
|
raise ValueError(
|
|
"Only direct subclasses of Document may set "
|
|
'"allow_inheritance" to False'
|
|
)
|
|
|
|
# Set default collection name
|
|
if "collection" not in meta:
|
|
meta["collection"] = (
|
|
"".join("_%s" % c if c.isupper() else c for c in name)
|
|
.strip("_")
|
|
.lower()
|
|
)
|
|
attrs["_meta"] = meta
|
|
|
|
# Call super and get the new class
|
|
new_class = super_new(mcs, name, bases, attrs)
|
|
|
|
meta = new_class._meta
|
|
|
|
# Set index specifications
|
|
meta["index_specs"] = new_class._build_index_specs(meta["indexes"])
|
|
|
|
# If collection is a callable - call it and set the value
|
|
collection = meta.get("collection")
|
|
if callable(collection):
|
|
new_class._meta["collection"] = collection(new_class)
|
|
|
|
# Provide a default queryset unless exists or one has been set
|
|
if "objects" not in dir(new_class):
|
|
new_class.objects = QuerySetManager()
|
|
|
|
# Validate the fields and set primary key if needed
|
|
for field_name, field in new_class._fields.items():
|
|
if field.primary_key:
|
|
# Ensure only one primary key is set
|
|
current_pk = new_class._meta.get("id_field")
|
|
if current_pk and current_pk != field_name:
|
|
raise ValueError("Cannot override primary key field")
|
|
|
|
# Set primary key
|
|
if not current_pk:
|
|
new_class._meta["id_field"] = field_name
|
|
new_class.id = field
|
|
|
|
# If the document doesn't explicitly define a primary key field, create
|
|
# one. Make it an ObjectIdField and give it a non-clashing name ("id"
|
|
# by default, but can be different if that one's taken).
|
|
if not new_class._meta.get("id_field"):
|
|
id_name, id_db_name = mcs.get_auto_id_names(new_class)
|
|
new_class._meta["id_field"] = id_name
|
|
new_class._fields[id_name] = ObjectIdField(db_field=id_db_name)
|
|
new_class._fields[id_name].name = id_name
|
|
new_class.id = new_class._fields[id_name]
|
|
new_class._db_field_map[id_name] = id_db_name
|
|
new_class._reverse_db_field_map[id_db_name] = id_name
|
|
|
|
# Prepend the ID field to _fields_ordered (so that it's *always*
|
|
# the first field).
|
|
new_class._fields_ordered = (id_name,) + new_class._fields_ordered
|
|
|
|
# Merge in exceptions with parent hierarchy.
|
|
exceptions_to_merge = (DoesNotExist, MultipleObjectsReturned)
|
|
module = attrs.get("__module__")
|
|
for exc in exceptions_to_merge:
|
|
name = exc.__name__
|
|
parents = tuple(
|
|
getattr(base, name) for base in flattened_bases if hasattr(base, name)
|
|
) or (exc,)
|
|
|
|
# Create a new exception and set it as an attribute on the new
|
|
# class.
|
|
exception = type(name, parents, {"__module__": module})
|
|
setattr(new_class, name, exception)
|
|
|
|
return new_class
|
|
|
|
@classmethod
|
|
def get_auto_id_names(mcs, new_class):
|
|
"""Find a name for the automatic ID field for the given new class.
|
|
|
|
Return a two-element tuple where the first item is the field name (i.e.
|
|
the attribute name on the object) and the second element is the DB
|
|
field name (i.e. the name of the key stored in MongoDB).
|
|
|
|
Defaults to ('id', '_id'), or generates a non-clashing name in the form
|
|
of ('auto_id_X', '_auto_id_X') if the default name is already taken.
|
|
"""
|
|
id_name, id_db_name = ("id", "_id")
|
|
existing_fields = {field_name for field_name in new_class._fields}
|
|
existing_db_fields = {v.db_field for v in new_class._fields.values()}
|
|
if id_name not in existing_fields and id_db_name not in existing_db_fields:
|
|
return id_name, id_db_name
|
|
|
|
id_basename, id_db_basename, i = ("auto_id", "_auto_id", 0)
|
|
for i in itertools.count():
|
|
id_name = f"{id_basename}_{i}"
|
|
id_db_name = f"{id_db_basename}_{i}"
|
|
if id_name not in existing_fields and id_db_name not in existing_db_fields:
|
|
return id_name, id_db_name
|
|
|
|
|
|
class MetaDict(dict):
|
|
"""Custom dictionary for meta classes.
|
|
Handles the merging of set indexes
|
|
"""
|
|
|
|
_merge_options = ("indexes",)
|
|
|
|
def merge(self, new_options):
|
|
for k, v in new_options.items():
|
|
if k in self._merge_options:
|
|
self[k] = self.get(k, []) + v
|
|
else:
|
|
self[k] = v
|
|
|
|
|
|
class BasesTuple(tuple):
|
|
"""Special class to handle introspection of bases tuple in __new__"""
|
|
|
|
pass
|