mongoengine/mongoengine/base/datastructures.py

492 lines
16 KiB
Python

import itertools
import weakref
from bson import DBRef
import six
from mongoengine.common import _import_class
from mongoengine.errors import DoesNotExist, MultipleObjectsReturned
__all__ = ('BaseDict', 'BaseList', 'EmbeddedDocumentList', 'LazyReference')
class BaseDict(dict):
"""A special dict so we can watch any changes."""
_dereferenced = False
_instance = None
_name = None
def __init__(self, dict_items, instance, name):
Document = _import_class('Document')
EmbeddedDocument = _import_class('EmbeddedDocument')
if isinstance(instance, (Document, EmbeddedDocument)):
self._instance = weakref.proxy(instance)
self._name = name
super(BaseDict, self).__init__(dict_items)
def __getitem__(self, key, *args, **kwargs):
value = super(BaseDict, self).__getitem__(key)
EmbeddedDocument = _import_class('EmbeddedDocument')
if isinstance(value, EmbeddedDocument) and value._instance is None:
value._instance = self._instance
elif not isinstance(value, BaseDict) and isinstance(value, dict):
value = BaseDict(value, None, '%s.%s' % (self._name, key))
super(BaseDict, self).__setitem__(key, value)
value._instance = self._instance
elif not isinstance(value, BaseList) and isinstance(value, list):
value = BaseList(value, None, '%s.%s' % (self._name, key))
super(BaseDict, self).__setitem__(key, value)
value._instance = self._instance
return value
def __setitem__(self, key, value, *args, **kwargs):
self._mark_as_changed(key)
return super(BaseDict, self).__setitem__(key, value)
def __delete__(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).__delete__(*args, **kwargs)
def __delitem__(self, key, *args, **kwargs):
self._mark_as_changed(key)
return super(BaseDict, self).__delitem__(key)
def __delattr__(self, key, *args, **kwargs):
self._mark_as_changed(key)
return super(BaseDict, self).__delattr__(key)
def __getstate__(self):
self.instance = None
self._dereferenced = False
return self
def __setstate__(self, state):
self = state
return self
def clear(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).clear()
def pop(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).pop(*args, **kwargs)
def popitem(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).popitem()
def setdefault(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).setdefault(*args, **kwargs)
def update(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseDict, self).update(*args, **kwargs)
def _mark_as_changed(self, key=None):
if hasattr(self._instance, '_mark_as_changed'):
if key:
self._instance._mark_as_changed('%s.%s' % (self._name, key))
else:
self._instance._mark_as_changed(self._name)
class BaseList(list):
"""A special list so we can watch any changes."""
_dereferenced = False
_instance = None
_name = None
def __init__(self, list_items, instance, name):
Document = _import_class('Document')
EmbeddedDocument = _import_class('EmbeddedDocument')
if isinstance(instance, (Document, EmbeddedDocument)):
self._instance = weakref.proxy(instance)
self._name = name
super(BaseList, self).__init__(list_items)
def __getitem__(self, key, *args, **kwargs):
value = super(BaseList, self).__getitem__(key)
EmbeddedDocument = _import_class('EmbeddedDocument')
if isinstance(value, EmbeddedDocument) and value._instance is None:
value._instance = self._instance
elif not isinstance(value, BaseDict) and isinstance(value, dict):
value = BaseDict(value, None, '%s.%s' % (self._name, key))
super(BaseList, self).__setitem__(key, value)
value._instance = self._instance
elif not isinstance(value, BaseList) and isinstance(value, list):
value = BaseList(value, None, '%s.%s' % (self._name, key))
super(BaseList, self).__setitem__(key, value)
value._instance = self._instance
return value
def __iter__(self):
for v in super(BaseList, self).__iter__():
yield v
def __setitem__(self, key, value, *args, **kwargs):
if isinstance(key, slice):
self._mark_as_changed()
else:
self._mark_as_changed(key)
return super(BaseList, self).__setitem__(key, value)
def __delitem__(self, key):
self._mark_as_changed()
return super(BaseList, self).__delitem__(key)
def __setslice__(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).__setslice__(*args, **kwargs)
def __delslice__(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).__delslice__(*args, **kwargs)
def __getstate__(self):
self.instance = None
self._dereferenced = False
return self
def __setstate__(self, state):
self = state
return self
def __iadd__(self, other):
self._mark_as_changed()
return super(BaseList, self).__iadd__(other)
def __imul__(self, other):
self._mark_as_changed()
return super(BaseList, self).__imul__(other)
def append(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).append(*args, **kwargs)
def extend(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).extend(*args, **kwargs)
def insert(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).insert(*args, **kwargs)
def pop(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).pop(*args, **kwargs)
def remove(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).remove(*args, **kwargs)
def reverse(self):
self._mark_as_changed()
return super(BaseList, self).reverse()
def sort(self, *args, **kwargs):
self._mark_as_changed()
return super(BaseList, self).sort(*args, **kwargs)
def _mark_as_changed(self, key=None):
if hasattr(self._instance, '_mark_as_changed'):
if key:
self._instance._mark_as_changed(
'%s.%s' % (self._name, key % len(self))
)
else:
self._instance._mark_as_changed(self._name)
class EmbeddedDocumentList(BaseList):
@classmethod
def __match_all(cls, embedded_doc, kwargs):
"""Return True if a given embedded doc matches all the filter
kwargs. If it doesn't return False.
"""
for key, expected_value in kwargs.items():
doc_val = getattr(embedded_doc, key)
if doc_val != expected_value and six.text_type(doc_val) != expected_value:
return False
return True
@classmethod
def __only_matches(cls, embedded_docs, kwargs):
"""Return embedded docs that match the filter kwargs."""
if not kwargs:
return embedded_docs
return [doc for doc in embedded_docs if cls.__match_all(doc, kwargs)]
def __init__(self, list_items, instance, name):
super(EmbeddedDocumentList, self).__init__(list_items, instance, name)
self._instance = instance
def filter(self, **kwargs):
"""
Filters the list by only including embedded documents with the
given keyword arguments.
This method only supports simple comparison (e.g: .filter(name='John Doe'))
and does not support operators like __gte, __lte, __icontains like queryset.filter does
:param kwargs: The keyword arguments corresponding to the fields to
filter on. *Multiple arguments are treated as if they are ANDed
together.*
:return: A new ``EmbeddedDocumentList`` containing the matching
embedded documents.
Raises ``AttributeError`` if a given keyword is not a valid field for
the embedded document class.
"""
values = self.__only_matches(self, kwargs)
return EmbeddedDocumentList(values, self._instance, self._name)
def exclude(self, **kwargs):
"""
Filters the list by excluding embedded documents with the given
keyword arguments.
:param kwargs: The keyword arguments corresponding to the fields to
exclude on. *Multiple arguments are treated as if they are ANDed
together.*
:return: A new ``EmbeddedDocumentList`` containing the non-matching
embedded documents.
Raises ``AttributeError`` if a given keyword is not a valid field for
the embedded document class.
"""
exclude = self.__only_matches(self, kwargs)
values = [item for item in self if item not in exclude]
return EmbeddedDocumentList(values, self._instance, self._name)
def count(self):
"""
The number of embedded documents in the list.
:return: The length of the list, equivalent to the result of ``len()``.
"""
return len(self)
def get(self, **kwargs):
"""
Retrieves an embedded document determined by the given keyword
arguments.
:param kwargs: The keyword arguments corresponding to the fields to
search on. *Multiple arguments are treated as if they are ANDed
together.*
:return: The embedded document matched by the given keyword arguments.
Raises ``DoesNotExist`` if the arguments used to query an embedded
document returns no results. ``MultipleObjectsReturned`` if more
than one result is returned.
"""
values = self.__only_matches(self, kwargs)
if len(values) == 0:
raise DoesNotExist(
'%s matching query does not exist.' % self._name
)
elif len(values) > 1:
raise MultipleObjectsReturned(
'%d items returned, instead of 1' % len(values)
)
return values[0]
def first(self):
"""Return the first embedded document in the list, or ``None``
if empty.
"""
if len(self) > 0:
return self[0]
def create(self, **values):
"""
Creates a new embedded document and saves it to the database.
.. note::
The embedded document changes are not automatically saved
to the database after calling this method.
:param values: A dictionary of values for the embedded document.
:return: The new embedded document instance.
"""
name = self._name
EmbeddedClass = self._instance._fields[name].field.document_type_obj
self._instance[self._name].append(EmbeddedClass(**values))
return self._instance[self._name][-1]
def save(self, *args, **kwargs):
"""
Saves the ancestor document.
:param args: Arguments passed up to the ancestor Document's save
method.
:param kwargs: Keyword arguments passed up to the ancestor Document's
save method.
"""
self._instance.save(*args, **kwargs)
def delete(self):
"""
Deletes the embedded documents from the database.
.. note::
The embedded document changes are not automatically saved
to the database after calling this method.
:return: The number of entries deleted.
"""
values = list(self)
for item in values:
self._instance[self._name].remove(item)
return len(values)
def update(self, **update):
"""
Updates the embedded documents with the given replacement values. This
function does not support mongoDB update operators such as ``inc__``.
.. note::
The embedded document changes are not automatically saved
to the database after calling this method.
:param update: A dictionary of update values to apply to each
embedded document.
:return: The number of entries updated.
"""
if len(update) == 0:
return 0
values = list(self)
for item in values:
for k, v in update.items():
setattr(item, k, v)
return len(values)
class StrictDict(object):
__slots__ = ()
_special_fields = set(['get', 'pop', 'iteritems', 'items', 'keys', 'create'])
_classes = {}
def __init__(self, **kwargs):
for k, v in kwargs.iteritems():
setattr(self, k, v)
def __getitem__(self, key):
key = '_reserved_' + key if key in self._special_fields else key
try:
return getattr(self, key)
except AttributeError:
raise KeyError(key)
def __setitem__(self, key, value):
key = '_reserved_' + key if key in self._special_fields else key
return setattr(self, key, value)
def __contains__(self, key):
return hasattr(self, key)
def get(self, key, default=None):
try:
return self[key]
except KeyError:
return default
def pop(self, key, default=None):
v = self.get(key, default)
try:
delattr(self, key)
except AttributeError:
pass
return v
def iteritems(self):
for key in self:
yield key, self[key]
def items(self):
return [(k, self[k]) for k in iter(self)]
def iterkeys(self):
return iter(self)
def keys(self):
return list(iter(self))
def __iter__(self):
return (key for key in self.__slots__ if hasattr(self, key))
def __len__(self):
return len(list(self.iteritems()))
def __eq__(self, other):
return self.items() == other.items()
def __ne__(self, other):
return self.items() != other.items()
@classmethod
def create(cls, allowed_keys):
allowed_keys_tuple = tuple(('_reserved_' + k if k in cls._special_fields else k) for k in allowed_keys)
allowed_keys = frozenset(allowed_keys_tuple)
if allowed_keys not in cls._classes:
class SpecificStrictDict(cls):
__slots__ = allowed_keys_tuple
def __repr__(self):
return '{%s}' % ', '.join('"{0!s}": {1!r}'.format(k, v) for k, v in self.items())
cls._classes[allowed_keys] = SpecificStrictDict
return cls._classes[allowed_keys]
class LazyReference(DBRef):
__slots__ = ('_cached_doc', 'passthrough', 'document_type')
def fetch(self, force=False):
if not self._cached_doc or force:
self._cached_doc = self.document_type.objects.get(pk=self.pk)
if not self._cached_doc:
raise DoesNotExist('Trying to dereference unknown document %s' % (self))
return self._cached_doc
@property
def pk(self):
return self.id
def __init__(self, document_type, pk, cached_doc=None, passthrough=False):
self.document_type = document_type
self._cached_doc = cached_doc
self.passthrough = passthrough
super(LazyReference, self).__init__(self.document_type._get_collection_name(), pk)
def __getitem__(self, name):
if not self.passthrough:
raise KeyError()
document = self.fetch()
return document[name]
def __getattr__(self, name):
if not object.__getattribute__(self, 'passthrough'):
raise AttributeError()
document = self.fetch()
try:
return document[name]
except KeyError:
raise AttributeError()
def __repr__(self):
return "<LazyReference(%s, %r)>" % (self.document_type, self.pk)