summaryrefslogtreecommitdiff
path: root/kvmd/aiotools.py
blob: bd4bd37e135ae343eb90a0f023c7d13bca48519d (plain)
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
# ========================================================================== #
#                                                                            #
#    KVMD - The main Pi-KVM daemon.                                          #
#                                                                            #
#    Copyright (C) 2018  Maxim Devaev <[email protected]>                    #
#                                                                            #
#    This program is free software: you can redistribute it and/or modify    #
#    it under the terms of the GNU General Public License as published by    #
#    the Free Software Foundation, either version 3 of the License, or       #
#    (at your option) any later version.                                     #
#                                                                            #
#    This program is distributed in the hope that it will be useful,         #
#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
#    GNU General Public License for more details.                            #
#                                                                            #
#    You should have received a copy of the GNU General Public License       #
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
#                                                                            #
# ========================================================================== #


import os
import asyncio
import asyncio.queues
import functools
import types

import typing

from typing import Tuple
from typing import List
from typing import Set
from typing import Callable
from typing import Awaitable
from typing import Coroutine
from typing import Type
from typing import TypeVar
from typing import Optional
from typing import Any

import aiohttp

import aiofiles
import aiofiles.base

from .logging import get_logger


# =====
_ATTR_SHORT_TASK = "_aiotools_short_task"

_MethodT = TypeVar("_MethodT", bound=Callable[..., Any])
_RetvalT = TypeVar("_RetvalT")


# =====
def atomic(method: _MethodT) -> _MethodT:
    @functools.wraps(method)
    async def wrapper(*args: Any, **kwargs: Any) -> Any:
        return (await asyncio.shield(method(*args, **kwargs)))
    return typing.cast(_MethodT, wrapper)


# =====
def create_short_task(coro: Coroutine) -> asyncio.Task:
    task = asyncio.create_task(coro)
    setattr(task, _ATTR_SHORT_TASK, True)
    return task


def get_short_tasks() -> List[asyncio.Task]:
    return [
        task
        for task in asyncio.Task.all_tasks()
        if getattr(task, _ATTR_SHORT_TASK, False)
    ]


# =====
async def run_async(method: Callable[..., _RetvalT], *args: Any) -> _RetvalT:
    return (await asyncio.get_running_loop().run_in_executor(None, method, *args))


def run_sync(coro: Coroutine[Any, Any, _RetvalT]) -> _RetvalT:
    return asyncio.get_event_loop().run_until_complete(coro)


# =====
async def wait_infinite() -> None:
    await asyncio.get_event_loop().create_future()


async def wait_first(*aws: Awaitable) -> Tuple[Set[asyncio.Future], Set[asyncio.Future]]:
    return (await asyncio.wait(list(aws), return_when=asyncio.FIRST_COMPLETED))


# =====
def raise_not_200(response: aiohttp.ClientResponse) -> None:
    if response.status != 200:
        assert response.reason is not None
        response.release()
        raise aiohttp.ClientResponseError(
            response.request_info,
            response.history,
            status=response.status,
            message=response.reason,
            headers=response.headers,
        )


# =====
async def afile_write_now(afile: aiofiles.base.AiofilesContextManager, data: bytes) -> None:
    await afile.write(data)
    await afile.flush()
    await run_async(os.fsync, afile.fileno())


# =====
class AioNotifier:
    def __init__(self) -> None:
        self.__queue: asyncio.queues.Queue = asyncio.Queue()

    async def notify(self) -> None:
        await self.__queue.put(None)

    async def wait(self) -> None:
        await self.__queue.get()
        while not self.__queue.empty():
            await self.__queue.get()


# =====
class AioExclusiveRegion:
    def __init__(
        self,
        exc_type: Type[Exception],
        notifier: Optional[AioNotifier]=None,
    ) -> None:

        self.__exc_type = exc_type
        self.__notifier = notifier

        self.__busy = False

    def get_exc_type(self) -> Type[Exception]:
        return self.__exc_type

    def is_busy(self) -> bool:
        return self.__busy

    async def enter(self) -> None:
        if not self.__busy:
            self.__busy = True
            try:
                if self.__notifier:
                    await self.__notifier.notify()
            except:  # noqa: E722
                self.__busy = False
                raise
            return
        raise self.__exc_type()

    async def exit(self) -> None:
        self.__busy = False
        if self.__notifier:
            await self.__notifier.notify()

    async def __aenter__(self) -> None:
        await self.enter()

    async def __aexit__(
        self,
        _exc_type: Type[BaseException],
        _exc: BaseException,
        _tb: types.TracebackType,
    ) -> None:

        await self.exit()


async def run_region_task(
    msg: str,
    region: AioExclusiveRegion,
    method: Callable[..., Coroutine[Any, Any, None]],
    *args: Any,
    **kwargs: Any,
) -> None:

    entered = asyncio.Future()  # type: ignore

    async def wrapper() -> None:
        try:
            async with region:
                entered.set_result(None)
                await method(*args, **kwargs)
        except region.get_exc_type():
            raise
        except Exception:
            get_logger(0).exception(msg)

    task = create_short_task(wrapper())
    await asyncio.wait([entered, task], return_when=asyncio.FIRST_COMPLETED)

    if entered.done():
        return
    if (exc := task.exception()) is not None:  # noqa: E203,E231
        raise exc