/usr/share/pyshared/mongoengine/dereference.py is in python-mongoengine 0.6.13-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | from bson import DBRef, SON
from base import (BaseDict, BaseList, TopLevelDocumentMetaclass, get_document)
from fields import (ReferenceField, ListField, DictField, MapField)
from connection import get_db
from queryset import QuerySet
from document import Document
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 convertion 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, basestring):
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 instance._fields:
doc_type = instance._fields[name].field
if isinstance(doc_type, ReferenceField):
doc_type = doc_type.document_type
if all([i.__class__ == doc_type for i in items]):
return 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 = items.iteritems()
# Recursively find dbreferences
depth += 1
for k, item in iterator:
if hasattr(item, '_fields'):
for field_name, field in item._fields.iteritems():
v = item._data.get(field_name, None)
if isinstance(v, (DBRef)):
reference_map.setdefault(field.document_type, []).append(v.id)
elif isinstance(v, (dict, SON)) and '_ref' in v:
reference_map.setdefault(get_document(v['_cls']), []).append(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.iteritems():
if isinstance(field_cls, (Document, TopLevelDocumentMetaclass)):
key = field_cls
reference_map.setdefault(key, []).extend(refs)
elif isinstance(item, (DBRef)):
reference_map.setdefault(item.collection, []).append(item.id)
elif isinstance(item, (dict, SON)) and '_ref' in item:
reference_map.setdefault(get_document(item['_cls']), []).append(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.iteritems():
reference_map.setdefault(key, []).extend(refs)
return reference_map
def _fetch_objects(self, doc_type=None):
"""Fetch all references and convert to their document objects
"""
object_map = {}
for col, dbrefs in self.reference_map.iteritems():
keys = object_map.keys()
refs = list(set([dbref for dbref in dbrefs if str(dbref) not in keys]))
if hasattr(col, 'objects'): # We have a document class for the refs
references = col.objects.in_bulk(refs)
for key, doc in references.iteritems():
object_map[key] = doc
else: # Generic reference: use the refs data to convert to document
if doc_type and not isinstance(doc_type, (ListField, DictField, MapField,) ):
references = doc_type._get_db()[col].find({'_id': {'$in': refs}})
for ref in references:
doc = doc_type._from_son(ref)
object_map[doc.id] = doc
else:
references = get_db()[col].find({'_id': {'$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 col.split('_')))._from_son(ref)
else:
doc = doc_type._from_son(ref)
object_map[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'].id, items)
elif '_types' in items and '_cls' in items:
doc = get_document(items['_cls'])._from_son(items)
doc._data = self._attach_objects(doc._data, depth, doc, name)
return doc
if not hasattr(items, 'items'):
is_list = True
iterator = enumerate(items)
data = []
else:
is_list = False
iterator = items.iteritems()
data = {}
depth += 1
for k, v in iterator:
if is_list:
data.append(v)
else:
data[k] = v
if k in self.object_map:
data[k] = self.object_map[k]
elif hasattr(v, '_fields'):
for field_name, field in v._fields.iteritems():
v = data[k]._data.get(field_name, None)
if isinstance(v, (DBRef)):
data[k]._data[field_name] = self.object_map.get(v.id, v)
elif isinstance(v, (dict, SON)) and '_ref' in v:
data[k]._data[field_name] = self.object_map.get(v['_ref'].id, v)
elif isinstance(v, dict) and depth <= self.max_depth:
data[k]._data[field_name] = self._attach_objects(v, depth, instance=instance, name=name)
elif isinstance(v, (list, tuple)) and depth <= self.max_depth:
data[k]._data[field_name] = self._attach_objects(v, depth, instance=instance, name=name)
elif isinstance(v, (dict, list, tuple)) and depth <= self.max_depth:
data[k] = self._attach_objects(v, depth - 1, instance=instance, name=name)
elif hasattr(v, 'id'):
data[k] = self.object_map.get(v.id, v)
if instance and name:
if is_list:
return BaseList(data, instance, name)
return BaseDict(data, instance, name)
depth += 1
return data
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