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
|
# Copyright (c) 2011 X.commerce, a business unit of eBay Inc.
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Piston Cloud Computing, Inc.
# Copyright 2012 Cloudscaling Group, Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""
SQLAlchemy models.
"""
import six
from oslo_utils import timeutils
from sqlalchemy import Column
from sqlalchemy import DateTime
from sqlalchemy.orm import object_mapper
from oslo_db.sqlalchemy import types
class ModelBase(six.Iterator):
"""Base class for models."""
__table_initialized__ = False
def save(self, session):
"""Save this object."""
# NOTE(boris-42): This part of code should be look like:
# session.add(self)
# session.flush()
# But there is a bug in sqlalchemy and eventlet that
# raises NoneType exception if there is no running
# transaction and rollback is called. As long as
# sqlalchemy has this bug we have to create transaction
# explicitly.
with session.begin(subtransactions=True):
session.add(self)
session.flush()
def __setitem__(self, key, value):
setattr(self, key, value)
def __getitem__(self, key):
return getattr(self, key)
def __contains__(self, key):
# Don't use hasattr() because hasattr() catches any exception, not only
# AttributeError. We want to passthrough SQLAlchemy exceptions
# (ex: sqlalchemy.orm.exc.DetachedInstanceError).
try:
getattr(self, key)
except AttributeError:
return False
else:
return True
def get(self, key, default=None):
return getattr(self, key, default)
@property
def _extra_keys(self):
"""Specifies custom fields
Subclasses can override this property to return a list
of custom fields that should be included in their dict
representation.
For reference check tests/db/sqlalchemy/test_models.py
"""
return []
def __iter__(self):
columns = list(dict(object_mapper(self).columns).keys())
# NOTE(russellb): Allow models to specify other keys that can be looked
# up, beyond the actual db columns. An example would be the 'name'
# property for an Instance.
columns.extend(self._extra_keys)
return ModelIterator(self, iter(columns))
def update(self, values):
"""Make the model object behave like a dict."""
for k, v in six.iteritems(values):
setattr(self, k, v)
def _as_dict(self):
"""Make the model object behave like a dict.
Includes attributes from joins.
"""
local = dict((key, value) for key, value in self)
joined = dict([(k, v) for k, v in six.iteritems(self.__dict__)
if not k[0] == '_'])
local.update(joined)
return local
def iteritems(self):
"""Make the model object behave like a dict."""
return six.iteritems(self._as_dict())
def items(self):
"""Make the model object behave like a dict."""
return self._as_dict().items()
def keys(self):
"""Make the model object behave like a dict."""
return [key for key, value in self.iteritems()]
class ModelIterator(six.Iterator):
def __init__(self, model, columns):
self.model = model
self.i = columns
def __iter__(self):
return self
# In Python 3, __next__() has replaced next().
def __next__(self):
n = six.advance_iterator(self.i)
return n, getattr(self.model, n)
class TimestampMixin(object):
created_at = Column(DateTime, default=lambda: timeutils.utcnow())
updated_at = Column(DateTime, onupdate=lambda: timeutils.utcnow())
class SoftDeleteMixin(object):
deleted_at = Column(DateTime)
deleted = Column(types.SoftDeleteInteger, default=0)
def soft_delete(self, session):
"""Mark this object as deleted."""
self.deleted = self.id
self.deleted_at = timeutils.utcnow()
self.save(session=session)
|
