|
1
|
1 |
|
import logging |
|
2
|
1 |
|
from asyncio import Lock |
|
3
|
1 |
|
from contextlib import AsyncExitStack |
|
4
|
1 |
|
from copy import copy |
|
5
|
1 |
|
from typing import ( |
|
6
|
|
|
Optional, |
|
7
|
|
|
Type, |
|
8
|
|
|
TypeVar, |
|
9
|
|
|
Awaitable, |
|
10
|
|
|
Generic, |
|
11
|
|
|
Collection, |
|
12
|
|
|
Union, |
|
13
|
|
|
ContextManager, |
|
14
|
|
|
AsyncContextManager, |
|
15
|
|
|
Iterator, |
|
16
|
|
|
Generator, |
|
17
|
|
|
AsyncGenerator, |
|
18
|
|
|
) |
|
19
|
|
|
|
|
20
|
1 |
|
from lagom.container import Container |
|
21
|
1 |
|
from lagom.definitions import Alias, ConstructionWithContainer, SingletonWrapper |
|
22
|
1 |
|
from lagom.exceptions import InvalidDependencyDefinition |
|
23
|
1 |
|
from lagom.experimental.definitions import AsyncConstructionWithContainer |
|
24
|
1 |
|
from lagom.interfaces import ReadableContainer, SpecialDepDefinition |
|
25
|
|
|
|
|
26
|
1 |
|
T = TypeVar("T") |
|
27
|
|
|
|
|
28
|
|
|
|
|
29
|
1 |
|
class AwaitableSingleton(Generic[T]): |
|
30
|
1 |
|
instance: Optional[T] |
|
31
|
1 |
|
constructor: ConstructionWithContainer[Awaitable[T]] |
|
32
|
1 |
|
container: Container |
|
33
|
1 |
|
_lock: Lock |
|
34
|
|
|
|
|
35
|
1 |
|
def __init__(self, constructor: ConstructionWithContainer, container: Container): |
|
36
|
1 |
|
self.instance = None |
|
37
|
1 |
|
self.constructor = constructor # type: ignore |
|
38
|
1 |
|
self.container = container |
|
39
|
1 |
|
self._lock = Lock() |
|
40
|
|
|
|
|
41
|
1 |
|
async def get(self) -> T: |
|
42
|
1 |
|
if not self.instance: |
|
43
|
1 |
|
async with self._lock: |
|
44
|
1 |
|
if not self.instance: |
|
45
|
1 |
|
self.instance = await self.constructor.get_instance(self.container) |
|
46
|
1 |
|
return self.instance |
|
47
|
|
|
|
|
48
|
|
|
|
|
49
|
1 |
|
class AsyncContextContainer(Container): |
|
50
|
1 |
|
async_exit_stack: Optional[AsyncExitStack] = None |
|
51
|
1 |
|
_context_types: Collection[Type] |
|
52
|
1 |
|
_context_singletons: Collection[Type] |
|
53
|
1 |
|
_root_context: bool = True |
|
54
|
|
|
|
|
55
|
1 |
|
def __init__( |
|
56
|
|
|
self, |
|
57
|
|
|
container: Container, |
|
58
|
|
|
context_types: Collection[Type], |
|
59
|
|
|
context_singletons: Collection[Type] = tuple(), |
|
60
|
|
|
log_undefined_deps: Union[bool, logging.Logger] = False, |
|
61
|
|
|
): |
|
62
|
1 |
|
super().__init__(container, log_undefined_deps) |
|
63
|
1 |
|
self._context_types = set(context_types) |
|
64
|
1 |
|
self._context_singletons = set(context_singletons) |
|
65
|
|
|
|
|
66
|
1 |
|
def clone(self) -> "AsyncContextContainer": |
|
67
|
|
|
"""returns a copy of the container |
|
68
|
|
|
:return: |
|
69
|
|
|
""" |
|
70
|
1 |
|
return AsyncContextContainer( |
|
71
|
|
|
self, |
|
72
|
|
|
context_types=self._context_types, |
|
73
|
|
|
context_singletons=self._context_singletons, |
|
74
|
|
|
log_undefined_deps=self._undefined_logger, |
|
75
|
|
|
) |
|
76
|
|
|
|
|
77
|
1 |
|
async def __aenter__(self): |
|
78
|
1 |
|
if not self.async_exit_stack and self._root_context: |
|
79
|
1 |
|
self.async_exit_stack = AsyncExitStack() |
|
80
|
|
|
|
|
81
|
1 |
|
if self.async_exit_stack and self._root_context: |
|
82
|
|
|
# All actual context definitions happen on a clone so that there's isolation between invocations |
|
83
|
1 |
|
in_context = self.clone() |
|
84
|
1 |
|
in_context.async_exit_stack = AsyncExitStack() |
|
85
|
1 |
|
in_context._root_context = False |
|
86
|
|
|
|
|
87
|
1 |
|
for dep_type in self._context_types: |
|
88
|
1 |
|
managed_dep = self._context_type_def(dep_type) |
|
89
|
1 |
|
key = Awaitable[dep_type] if isinstance(managed_dep, AsyncConstructionWithContainer) else dep_type # type: ignore |
|
90
|
1 |
|
in_context[key] = managed_dep # type: ignore |
|
91
|
1 |
|
for dep_type in self._context_singletons: |
|
92
|
1 |
|
managed_singleton = self._singleton_type_def(dep_type) |
|
93
|
1 |
|
key = AwaitableSingleton[dep_type] if isinstance(managed_singleton, AwaitableSingleton) else dep_type # type: ignore |
|
94
|
1 |
|
in_context[key] = managed_singleton # type: ignore |
|
95
|
|
|
|
|
96
|
|
|
# The parent context manager keeps track of the inner clone |
|
97
|
1 |
|
await self.async_exit_stack.enter_async_context(in_context) |
|
98
|
1 |
|
return in_context |
|
99
|
1 |
|
return self |
|
100
|
|
|
|
|
101
|
1 |
|
async def __aexit__(self, exc_type, exc_val, exc_tb): |
|
102
|
1 |
|
if self.async_exit_stack: |
|
103
|
1 |
|
await self.async_exit_stack.aclose() |
|
104
|
1 |
|
self.async_exit_stack = None |
|
105
|
|
|
|
|
106
|
1 |
|
def _context_type_def(self, dep_type: Type): |
|
107
|
1 |
|
type_def = self.get_definition(ContextManager[dep_type]) or self.get_definition(Iterator[dep_type]) or self.get_definition(Generator[dep_type, None, None]) or self.get_definition(AsyncGenerator[dep_type, None]) or self.get_definition(AsyncContextManager[dep_type]) # type: ignore |
|
108
|
1 |
|
if type_def is None: |
|
109
|
1 |
|
raise InvalidDependencyDefinition( |
|
110
|
|
|
f"A ContextManager[{dep_type}] should be defined. " |
|
111
|
|
|
f"This could be an Iterator[{dep_type}] or Generator[{dep_type}, None, None] " |
|
112
|
|
|
f"with the @contextmanager decorator" |
|
113
|
|
|
) |
|
114
|
1 |
|
if isinstance(type_def, Alias): |
|
115
|
|
|
# Without this we create a definition that points to |
|
116
|
|
|
# itself. |
|
117
|
1 |
|
type_def = copy(type_def) |
|
118
|
1 |
|
type_def.skip_definitions = True |
|
119
|
1 |
|
if self.get_definition(AsyncGenerator[dep_type, None]) or self.get_definition(AsyncContextManager[dep_type]): # type: ignore |
|
120
|
1 |
|
return AsyncConstructionWithContainer(lambda c: self._async_context_resolver(c, type_def)) # type: ignore |
|
121
|
1 |
|
return ConstructionWithContainer(lambda c: self._context_resolver(c, type_def)) # type: ignore |
|
122
|
|
|
|
|
123
|
1 |
|
def _context_resolver(self, c: ReadableContainer, type_def: SpecialDepDefinition): |
|
124
|
|
|
""" |
|
125
|
|
|
Takes an existing definition which must be a context manager. Returns |
|
126
|
|
|
the value of the context manager from __enter__ and then places the |
|
127
|
|
|
__exit__ in this container's exit stack |
|
128
|
|
|
""" |
|
129
|
1 |
|
assert self.async_exit_stack, "Types can only be resolved within an async with" |
|
130
|
1 |
|
context_manager = type_def.get_instance(c) |
|
131
|
1 |
|
return self.async_exit_stack.enter_context(context_manager) |
|
132
|
|
|
|
|
133
|
1 |
|
def _async_context_resolver( |
|
134
|
|
|
self, c: ReadableContainer, type_def: SpecialDepDefinition |
|
135
|
|
|
): |
|
136
|
|
|
""" |
|
137
|
|
|
Takes an existing definition which must be a context manager. Returns |
|
138
|
|
|
the value of the context manager from __aenter__ and then places the |
|
139
|
|
|
__aexit__ in this container's exit stack |
|
140
|
|
|
""" |
|
141
|
1 |
|
assert self.async_exit_stack, "Types can only be resolved within an async with" |
|
142
|
1 |
|
context_manager = type_def.get_instance(c) |
|
143
|
1 |
|
return self.async_exit_stack.enter_async_context(context_manager) |
|
144
|
|
|
|
|
145
|
1 |
|
def _singleton_type_def(self, dep_type: Type): |
|
146
|
|
|
""" |
|
147
|
|
|
The same as context_type_def but acts as a singleton within this container |
|
148
|
|
|
""" |
|
149
|
1 |
|
type_def = self._context_type_def(dep_type) |
|
150
|
1 |
|
if isinstance(type_def, AsyncConstructionWithContainer): |
|
151
|
1 |
|
return AwaitableSingleton(type_def, self) |
|
152
|
|
|
return SingletonWrapper(type_def) |
|
153
|
|
|
|
meadsteve /
lagom
