|
1
|
|
|
"""Base classes for mapping.""" |
|
2
|
|
|
|
|
3
|
1 |
|
import abc |
|
4
|
1 |
|
import functools |
|
5
|
|
|
|
|
6
|
1 |
|
from .. import common |
|
7
|
|
|
|
|
8
|
|
|
|
|
9
|
1 |
|
log = common.logger(__name__) |
|
10
|
|
|
|
|
11
|
1 |
|
TAG = '_modified_by_yorm' |
|
12
|
|
|
|
|
13
|
|
|
|
|
14
|
1 |
|
def fetch_before(method): |
|
15
|
|
|
"""Decorator for methods that should fetch before call.""" |
|
16
|
|
|
|
|
17
|
1 |
|
if getattr(method, TAG, False): |
|
18
|
1 |
|
return method |
|
19
|
|
|
|
|
20
|
1 |
|
@functools.wraps(method) |
|
21
|
|
|
def wrapped(self, *args, **kwargs): |
|
22
|
|
|
"""Decorated method.""" |
|
23
|
1 |
|
if not _private_call(method, args): |
|
24
|
1 |
|
mapper = common.get_mapper(self) |
|
25
|
1 |
|
if mapper and mapper.modified: |
|
26
|
1 |
|
log.debug("Fetching before call: %s", method.__name__) |
|
27
|
1 |
|
mapper.fetch() |
|
28
|
1 |
|
if mapper.store_after_fetch: |
|
29
|
1 |
|
mapper.store() |
|
30
|
1 |
|
mapper.modified = False |
|
31
|
|
|
|
|
32
|
1 |
|
return method(self, *args, **kwargs) |
|
33
|
|
|
|
|
34
|
1 |
|
setattr(wrapped, TAG, True) |
|
35
|
|
|
|
|
36
|
1 |
|
return wrapped |
|
37
|
|
|
|
|
38
|
|
|
|
|
39
|
1 |
|
def store_after(method): |
|
40
|
|
|
"""Decorator for methods that should store after call.""" |
|
41
|
|
|
|
|
42
|
1 |
|
if getattr(method, TAG, False): |
|
43
|
1 |
|
return method |
|
44
|
|
|
|
|
45
|
1 |
|
@functools.wraps(method) |
|
46
|
|
|
def wrapped(self, *args, **kwargs): |
|
47
|
|
|
"""Decorated method.""" |
|
48
|
1 |
|
result = method(self, *args, **kwargs) |
|
49
|
|
|
|
|
50
|
1 |
|
if not _private_call(method, args): |
|
51
|
1 |
|
mapper = common.get_mapper(self) |
|
52
|
1 |
|
if mapper and mapper.auto: |
|
53
|
1 |
|
log.debug("Storing after call: %s", method.__name__) |
|
54
|
1 |
|
mapper.store() |
|
55
|
|
|
|
|
56
|
1 |
|
return result |
|
57
|
|
|
|
|
58
|
1 |
|
setattr(wrapped, TAG, True) |
|
59
|
|
|
|
|
60
|
1 |
|
return wrapped |
|
61
|
|
|
|
|
62
|
|
|
|
|
63
|
1 |
|
def _private_call(method, args, prefix='_'): |
|
64
|
|
|
"""Determine if a call's first argument is a private variable name.""" |
|
65
|
1 |
|
if method.__name__ in ('__getattribute__', '__setattr__'): |
|
66
|
1 |
|
assert isinstance(args[0], str) |
|
67
|
1 |
|
return args[0].startswith(prefix) |
|
68
|
|
|
else: |
|
69
|
1 |
|
return False |
|
70
|
|
|
|
|
71
|
|
|
|
|
72
|
|
|
# TODO: move these methods inside of `Container` |
|
73
|
1 |
|
class Mappable(metaclass=abc.ABCMeta): |
|
74
|
|
|
"""Base class for objects with attributes mapped to file.""" |
|
75
|
|
|
|
|
76
|
|
|
# pylint: disable=no-member |
|
77
|
|
|
|
|
78
|
1 |
|
@fetch_before |
|
79
|
|
|
def __getattribute__(self, name): |
|
80
|
|
|
"""Trigger object update when reading attributes.""" |
|
81
|
1 |
|
return object.__getattribute__(self, name) |
|
82
|
|
|
|
|
83
|
1 |
|
@store_after |
|
84
|
|
|
def __setattr__(self, name, value): |
|
85
|
|
|
"""Trigger file update when setting attributes.""" |
|
86
|
1 |
|
super().__setattr__(name, value) |
|
87
|
|
|
|
|
88
|
1 |
|
@fetch_before |
|
89
|
|
|
def __iter__(self): |
|
90
|
|
|
"""Trigger object update when iterating.""" |
|
91
|
1 |
|
return super().__iter__() |
|
92
|
|
|
|
|
93
|
1 |
|
@fetch_before |
|
94
|
|
|
def __getitem__(self, key): |
|
95
|
|
|
"""Trigger object update when reading an index.""" |
|
96
|
1 |
|
return super().__getitem__(key) |
|
97
|
|
|
|
|
98
|
1 |
|
@store_after |
|
99
|
|
|
def __setitem__(self, key, value): |
|
100
|
|
|
"""Trigger file update when setting an index.""" |
|
101
|
1 |
|
super().__setitem__(key, value) |
|
102
|
|
|
|
|
103
|
1 |
|
@store_after |
|
104
|
|
|
def __delitem__(self, key): |
|
105
|
|
|
"""Trigger file update when deleting an index.""" |
|
106
|
1 |
|
super().__delitem__(key) |
|
107
|
|
|
|
|
108
|
1 |
|
@store_after |
|
109
|
|
|
def append(self, value): |
|
|
|
|
|
|
110
|
|
|
"""Trigger file update when appending items.""" |
|
111
|
1 |
|
super().append(value) |
|
112
|
|
|
|
|
113
|
|
|
|
|
114
|
1 |
|
def patch_methods(instance): |
|
115
|
1 |
|
log.debug("Patching methods on: %r", instance) |
|
116
|
1 |
|
cls = instance.__class__ |
|
117
|
|
|
|
|
118
|
|
|
# TODO: determine a way to share the lists of methods to patch |
|
119
|
1 |
|
for name in ['__getattribute__', '__iter__', '__getitem__']: |
|
120
|
1 |
|
try: |
|
121
|
1 |
|
method = getattr(cls, name) |
|
122
|
1 |
|
except AttributeError: |
|
123
|
1 |
|
log.trace("No method: %s", name) |
|
124
|
|
|
else: |
|
125
|
1 |
|
modified_method = fetch_before(method) |
|
126
|
1 |
|
setattr(cls, name, modified_method) |
|
127
|
1 |
|
log.trace("Patched to fetch before call: %s", name) |
|
128
|
|
|
|
|
129
|
1 |
|
for name in ['__setattr__', '__setitem__', '__delitem__', 'append']: |
|
130
|
1 |
|
try: |
|
131
|
1 |
|
method = getattr(cls, name) |
|
132
|
1 |
|
except AttributeError: |
|
133
|
1 |
|
log.trace("No method: %s", name) |
|
134
|
|
|
else: |
|
135
|
1 |
|
modified_method = store_after(method) |
|
136
|
1 |
|
setattr(cls, name, modified_method) |
|
137
|
|
|
log.trace("Patched to store after call: %s", name) |
|
138
|
|
|
|
jacebrowning /
yorm
If a method does not access any attributes of the class, it could also be implemented as a function or static method. This can help improve readability. For example
could be written as