/usr/lib/python3/dist-packages/mongoengine/dereference.py is in python3-mongoengine 0.10.6-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 | from bson import DBRef, SON
from .base import (
BaseDict, BaseList, EmbeddedDocumentList,
TopLevelDocumentMetaclass, get_document
)
from .fields import (ReferenceField, ListField, DictField, MapField)
from .connection import get_db
from .queryset import QuerySet
from .document import Document, EmbeddedDocument
class DeReference(object):
def __call__(self, items, max_depth=1, instance=None, name=None):
"""
Cheaply dereferences the items to a set depth.
Also handles the conversion of complex data types.
:param items: The iterable (dict, list, queryset) to be dereferenced.
:param max_depth: The maximum depth to recurse to
:param instance: The owning instance used for tracking changes by
:class:`~mongoengine.base.ComplexBaseField`
:param name: The name of the field, used for tracking changes by
:class:`~mongoengine.base.ComplexBaseField`
:param get: A boolean determining if being called by __get__
"""
if items is None or isinstance(items, str):
return items
# cheapest way to convert a queryset to a list
# list(queryset) uses a count() query to determine length
if isinstance(items, QuerySet):
items = [i for i in items]
self.max_depth = max_depth
doc_type = None
if instance and isinstance(instance, (Document, EmbeddedDocument,
TopLevelDocumentMetaclass)):
doc_type = instance._fields.get(name)
while hasattr(doc_type, 'field'):
doc_type = doc_type.field
if isinstance(doc_type, ReferenceField):
field = doc_type
doc_type = doc_type.document_type
is_list = not hasattr(items, 'items')
if is_list and all([i.__class__ == doc_type for i in items]):
return items
elif not is_list and all(
[i.__class__ == doc_type for i in list(items.values())]):
return items
elif not field.dbref:
if not hasattr(items, 'items'):
def _get_items(items):
new_items = []
for v in items:
if isinstance(v, list):
new_items.append(_get_items(v))
elif not isinstance(v, (DBRef, Document)):
new_items.append(field.to_python(v))
else:
new_items.append(v)
return new_items
items = _get_items(items)
else:
items = dict([
(k, field.to_python(v))
if not isinstance(v, (DBRef, Document)) else (k, v)
for k, v in items.items()]
)
self.reference_map = self._find_references(items)
self.object_map = self._fetch_objects(doc_type=doc_type)
return self._attach_objects(items, 0, instance, name)
def _find_references(self, items, depth=0):
"""
Recursively finds all db references to be dereferenced
:param items: The iterable (dict, list, queryset)
:param depth: The current depth of recursion
"""
reference_map = {}
if not items or depth >= self.max_depth:
return reference_map
# Determine the iterator to use
if not hasattr(items, 'items'):
iterator = enumerate(items)
else:
iterator = iter(items.items())
# Recursively find dbreferences
depth += 1
for k, item in iterator:
if isinstance(item, (Document, EmbeddedDocument)):
for field_name, field in item._fields.items():
v = item._data.get(field_name, None)
if isinstance(v, DBRef):
reference_map.setdefault(field.document_type, set()).add(v.id)
elif isinstance(v, (dict, SON)) and '_ref' in v:
reference_map.setdefault(get_document(v['_cls']), set()).add(v['_ref'].id)
elif isinstance(v, (dict, list, tuple)) and depth <= self.max_depth:
field_cls = getattr(getattr(field, 'field', None), 'document_type', None)
references = self._find_references(v, depth)
for key, refs in references.items():
if isinstance(field_cls, (Document, TopLevelDocumentMetaclass)):
key = field_cls
reference_map.setdefault(key, set()).update(refs)
elif isinstance(item, DBRef):
reference_map.setdefault(item.collection, set()).add(item.id)
elif isinstance(item, (dict, SON)) and '_ref' in item:
reference_map.setdefault(get_document(item['_cls']), set()).add(item['_ref'].id)
elif isinstance(item, (dict, list, tuple)) and depth - 1 <= self.max_depth:
references = self._find_references(item, depth - 1)
for key, refs in references.items():
reference_map.setdefault(key, set()).update(refs)
return reference_map
def _fetch_objects(self, doc_type=None):
"""Fetch all references and convert to their document objects
"""
object_map = {}
for collection, dbrefs in self.reference_map.items():
if hasattr(collection, 'objects'): # We have a document class for the refs
col_name = collection._get_collection_name()
refs = [dbref for dbref in dbrefs
if (col_name, dbref) not in object_map]
references = collection.objects.in_bulk(refs)
for key, doc in references.items():
object_map[(col_name, key)] = doc
else: # Generic reference: use the refs data to convert to document
if isinstance(doc_type, (ListField, DictField, MapField)):
continue
refs = [dbref for dbref in dbrefs
if (collection, dbref) not in object_map]
if doc_type:
references = doc_type._get_db()[collection].find({'_id': {'$in': refs}})
for ref in references:
doc = doc_type._from_son(ref)
object_map[(collection, doc.id)] = doc
else:
references = get_db()[collection].find({'_id': {'$in': refs}})
for ref in references:
if '_cls' in ref:
doc = get_document(ref["_cls"])._from_son(ref)
elif doc_type is None:
doc = get_document(
''.join(x.capitalize()
for x in collection.split('_')))._from_son(ref)
else:
doc = doc_type._from_son(ref)
object_map[(collection, doc.id)] = doc
return object_map
def _attach_objects(self, items, depth=0, instance=None, name=None):
"""
Recursively finds all db references to be dereferenced
:param items: The iterable (dict, list, queryset)
:param depth: The current depth of recursion
:param instance: The owning instance used for tracking changes by
:class:`~mongoengine.base.ComplexBaseField`
:param name: The name of the field, used for tracking changes by
:class:`~mongoengine.base.ComplexBaseField`
"""
if not items:
if isinstance(items, (BaseDict, BaseList)):
return items
if instance:
if isinstance(items, dict):
return BaseDict(items, instance, name)
else:
return BaseList(items, instance, name)
if isinstance(items, (dict, SON)):
if '_ref' in items:
return self.object_map.get(
(items['_ref'].collection, items['_ref'].id), items)
elif '_cls' in items:
doc = get_document(items['_cls'])._from_son(items)
_cls = doc._data.pop('_cls', None)
del items['_cls']
doc._data = self._attach_objects(doc._data, depth, doc, None)
if _cls is not None:
doc._data['_cls'] = _cls
return doc
if not hasattr(items, 'items'):
is_list = True
list_type = BaseList
if isinstance(items, EmbeddedDocumentList):
list_type = EmbeddedDocumentList
as_tuple = isinstance(items, tuple)
iterator = enumerate(items)
data = []
else:
is_list = False
iterator = iter(items.items())
data = {}
depth += 1
for k, v in iterator:
if is_list:
data.append(v)
else:
data[k] = v
if k in self.object_map and not is_list:
data[k] = self.object_map[k]
elif isinstance(v, (Document, EmbeddedDocument)):
for field_name, field in v._fields.items():
v = data[k]._data.get(field_name, None)
if isinstance(v, DBRef):
data[k]._data[field_name] = self.object_map.get(
(v.collection, v.id), v)
elif isinstance(v, (dict, SON)) and '_ref' in v:
data[k]._data[field_name] = self.object_map.get(
(v['_ref'].collection, v['_ref'].id), v)
elif isinstance(v, (dict, list, tuple)) and depth <= self.max_depth:
item_name = "{0}.{1}.{2}".format(name, k, field_name)
data[k]._data[field_name] = self._attach_objects(v, depth, instance=instance, name=item_name)
elif isinstance(v, (dict, list, tuple)) and depth <= self.max_depth:
item_name = '%s.%s' % (name, k) if name else name
data[k] = self._attach_objects(v, depth - 1, instance=instance, name=item_name)
elif hasattr(v, 'id'):
data[k] = self.object_map.get((v.collection, v.id), v)
if instance and name:
if is_list:
return tuple(data) if as_tuple else list_type(data, instance, name)
return BaseDict(data, instance, name)
depth += 1
return data
|