/
wiring.py
358 lines (280 loc) · 10.4 KB
/
wiring.py
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
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
"""Wiring module."""
import functools
import inspect
import pkgutil
import sys
from types import ModuleType
from typing import Optional, Iterable, Callable, Any, Tuple, Dict, Generic, TypeVar, cast
if sys.version_info < (3, 7):
from typing import GenericMeta
else:
class GenericMeta(type):
...
from . import providers
__all__ = (
'wire',
'unwire',
'Provide',
'Provider',
'Closing',
)
T = TypeVar('T')
Container = Any
class ProvidersMap:
def __init__(self, container):
self._container = container
self._map = self._create_providers_map(
current_providers=container.providers,
original_providers=container.declarative_parent.providers,
)
def resolve_provider(
self,
provider: providers.Provider,
) -> Optional[providers.Provider]:
if isinstance(provider, providers.Delegate):
return self._resolve_delegate(provider)
elif isinstance(provider, (
providers.ProvidedInstance,
providers.AttributeGetter,
providers.ItemGetter,
providers.MethodCaller,
)):
return self._resolve_provided_instance(provider)
elif isinstance(provider, providers.ConfigurationOption):
return self._resolve_config_option(provider)
elif isinstance(provider, providers.TypedConfigurationOption):
return self._resolve_config_option(provider.option, as_=provider.provides)
else:
return self._resolve_provider(provider)
def _resolve_delegate(
self,
original: providers.Delegate,
) -> Optional[providers.Provider]:
return self._resolve_provider(original.provides)
def _resolve_provided_instance(
self,
original: providers.Provider,
) -> Optional[providers.Provider]:
modifiers = []
while isinstance(original, (
providers.ProvidedInstance,
providers.AttributeGetter,
providers.ItemGetter,
providers.MethodCaller,
)):
modifiers.insert(0, original)
original = original.provides
new = self._resolve_provider(original)
if new is None:
return None
for modifier in modifiers:
if isinstance(modifier, providers.ProvidedInstance):
new = new.provided
elif isinstance(modifier, providers.AttributeGetter):
new = getattr(new, modifier.name)
elif isinstance(modifier, providers.ItemGetter):
new = new[modifier.name]
elif isinstance(modifier, providers.MethodCaller):
new = new.call(
*modifier.args,
**modifier.kwargs,
)
return new
def _resolve_config_option(
self,
original: providers.ConfigurationOption,
as_: Any = None,
) -> Optional[providers.Provider]:
original_root = original.root
new = self._resolve_provider(original_root)
if new is None:
return None
new = cast(providers.Configuration, new)
for segment in original.get_name_segments():
if providers.is_provider(segment):
segment = self.resolve_provider(segment)
new = new[segment]
else:
new = getattr(new, segment)
if as_:
new = new.as_(as_)
return new
def _resolve_provider(
self,
original: providers.Provider,
) -> Optional[providers.Provider]:
try:
return self._map[original]
except KeyError:
pass
@classmethod
def _create_providers_map(
cls,
current_providers: Dict[str, providers.Provider],
original_providers: Dict[str, providers.Provider],
) -> Dict[providers.Provider, providers.Provider]:
providers_map = {}
for provider_name, current_provider in current_providers.items():
original_provider = original_providers[provider_name]
providers_map[original_provider] = current_provider
if isinstance(current_provider, providers.Container) \
and isinstance(original_provider, providers.Container):
subcontainer_map = cls._create_providers_map(
current_providers=current_provider.container.providers,
original_providers=original_provider.container.providers,
)
providers_map.update(subcontainer_map)
return providers_map
def wire(
container: Container,
*,
modules: Optional[Iterable[ModuleType]] = None,
packages: Optional[Iterable[ModuleType]] = None,
) -> None:
"""Wire container providers with provided packages and modules."""
if not _is_declarative_container_instance(container):
raise Exception('Can wire only an instance of the declarative container')
if not modules:
modules = []
if packages:
for package in packages:
modules.extend(_fetch_modules(package))
providers_map = ProvidersMap(container)
for module in modules:
for name, member in inspect.getmembers(module):
if inspect.isfunction(member):
_patch_fn(module, name, member, providers_map)
elif inspect.isclass(member):
for method_name, method in inspect.getmembers(member, _is_method):
_patch_fn(member, method_name, method, providers_map)
def unwire(
*,
modules: Optional[Iterable[ModuleType]] = None,
packages: Optional[Iterable[ModuleType]] = None,
) -> None:
"""Wire provided packages and modules with previous wired providers."""
if not modules:
modules = []
if packages:
for package in packages:
modules.extend(_fetch_modules(package))
for module in modules:
for name, member in inspect.getmembers(module):
if inspect.isfunction(member):
_unpatch_fn(module, name, member)
elif inspect.isclass(member):
for method_name, method in inspect.getmembers(member, inspect.isfunction):
_unpatch_fn(member, method_name, method)
def _patch_fn(
module: ModuleType,
name: str,
fn: Callable[..., Any],
providers_map: ProvidersMap,
) -> None:
injections, closing = _resolve_injections(fn, providers_map)
if not injections:
return
setattr(module, name, _patch_with_injections(fn, injections, closing))
def _unpatch_fn(
module: ModuleType,
name: str,
fn: Callable[..., Any],
) -> None:
if not _is_patched(fn):
return
setattr(module, name, _get_original_from_patched(fn))
def _resolve_injections(
fn: Callable[..., Any],
providers_map: ProvidersMap,
) -> Tuple[Dict[str, Any], Dict[str, Any]]:
signature = inspect.signature(fn)
injections = {}
closing = {}
for parameter_name, parameter in signature.parameters.items():
if not isinstance(parameter.default, _Marker):
continue
marker = parameter.default
closing_modifier = False
if isinstance(marker, Closing):
closing_modifier = True
marker = marker.provider
provider = providers_map.resolve_provider(marker.provider)
if provider is None:
continue
if closing_modifier:
closing[parameter_name] = provider
if isinstance(marker, Provide):
injections[parameter_name] = provider
elif isinstance(marker, Provider):
injections[parameter_name] = provider.provider
return injections, closing
def _fetch_modules(package):
modules = [package]
for loader, module_name, is_pkg in pkgutil.walk_packages(
path=package.__path__,
prefix=package.__name__ + '.',
):
module = loader.find_module(module_name).load_module(module_name)
modules.append(module)
return modules
def _is_method(member):
return inspect.ismethod(member) or inspect.isfunction(member)
def _patch_with_injections(fn, injections, closing):
if inspect.iscoroutinefunction(fn):
@functools.wraps(fn)
async def _patched(*args, **kwargs):
to_inject = kwargs.copy()
for injection, provider in injections.items():
if injection not in kwargs:
to_inject[injection] = provider()
result = await fn(*args, **to_inject)
for injection, provider in closing.items():
if injection in kwargs:
continue
if not isinstance(provider, providers.Resource):
continue
provider.shutdown()
return result
else:
@functools.wraps(fn)
def _patched(*args, **kwargs):
to_inject = kwargs.copy()
for injection, provider in injections.items():
if injection not in kwargs:
to_inject[injection] = provider()
result = fn(*args, **to_inject)
for injection, provider in closing.items():
if injection in kwargs:
continue
if not isinstance(provider, providers.Resource):
continue
provider.shutdown()
return result
_patched.__wired__ = True
_patched.__original__ = fn
_patched.__injections__ = injections
_patched.__closing__ = closing
return _patched
def _is_patched(fn):
return getattr(fn, '__wired__', False) is True
def _get_original_from_patched(fn):
return getattr(fn, '__original__')
def _is_declarative_container_instance(instance: Any) -> bool:
return (not isinstance(instance, type)
and getattr(instance, '__IS_CONTAINER__', False) is True
and getattr(instance, 'declarative_parent', None) is not None)
class ClassGetItemMeta(GenericMeta):
def __getitem__(cls, item):
# Spike for Python 3.6
return cls(item)
class _Marker(Generic[T], metaclass=ClassGetItemMeta):
def __init__(self, provider: providers.Provider) -> None:
self.provider = provider
def __class_getitem__(cls, item) -> T:
return cls(item)
class Provide(_Marker):
...
class Provider(_Marker):
...
class Closing(_Marker):
...