summaryrefslogtreecommitdiff
path: root/backend/plugin.py
blob: fb636a4c17bc06826b2f25997a246b37c980f878 (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
import multiprocessing
from asyncio import (Lock, get_event_loop, new_event_loop,
                     open_unix_connection, set_event_loop, sleep,
                     start_unix_server)
from concurrent.futures import ProcessPoolExecutor
from importlib.util import module_from_spec, spec_from_file_location
from json import dumps, load, loads
from os import path, setuid
from signal import SIGINT, signal
from sys import exit
from time import time


class PluginWrapper:
    def __init__(self, file, plugin_directory, plugin_path) -> None:
        self.file = file
        self.plugin_directory = plugin_directory
        self.reader = None
        self.writer = None
        self.socket_addr = f"/tmp/plugin_socket_{time()}"
        self.method_call_lock = Lock()

        json = load(open(path.join(plugin_path, plugin_directory, "plugin.json"), "r"))

        self.legacy = False
        self.main_view_html = json["main_view_html"] if "main_view_html" in json else ""
        self.tile_view_html = json["tile_view_html"] if "tile_view_html" in json else ""
        self.legacy = self.main_view_html or self.tile_view_html

        self.name = json["name"]
        self.author = json["author"]
        self.flags = json["flags"]

        self.passive = not path.isfile(self.file)

    def __str__(self) -> str:
        return self.name

    def _init(self):
        signal(SIGINT, lambda s, f: exit(0))

        set_event_loop(new_event_loop())
        if self.passive:
            return
        setuid(0 if "root" in self.flags else 1000)
        spec = spec_from_file_location("_", self.file)
        module = module_from_spec(spec)
        spec.loader.exec_module(module)
        self.Plugin = module.Plugin

        if hasattr(self.Plugin, "_main"):
            get_event_loop().create_task(self.Plugin._main(self.Plugin))
        get_event_loop().create_task(self._setup_socket())
        get_event_loop().run_forever()

    async def _setup_socket(self):
        self.socket = await start_unix_server(self._listen_for_method_call, path=self.socket_addr)

    async def _listen_for_method_call(self, reader, writer):
        while True:
            data = loads((await reader.readline()).decode("utf-8"))
            if "stop" in data:
                get_event_loop().stop()
                while get_event_loop().is_running():
                    await sleep(0)
                get_event_loop().close()
                return
            d = {"res": None, "success": True}
            try:
                d["res"] = await getattr(self.Plugin, data["method"])(self.Plugin, **data["args"])
            except Exception as e:
                d["res"] = str(e)
                d["success"] = False
            finally:
                writer.write((dumps(d)+"\n").encode("utf-8"))
                await writer.drain()

    async def _open_socket_if_not_exists(self):
        if not self.reader:
            while True:
                try:
                    self.reader, self.writer = await open_unix_connection(self.socket_addr)
                    break
                except:
                    await sleep(0)

    def start(self):
        if self.passive:
            return self
        multiprocessing.set_start_method("fork")
        multiprocessing.Process(target=self._init).start()
        return self

    def stop(self):
        if self.passive:
            return
        async def _(self):
            await self._open_socket_if_not_exists()
            self.writer.write((dumps({"stop": True})+"\n").encode("utf-8"))
            await self.writer.drain()
            self.writer.close()
        get_event_loop().create_task(_(self))

    async def execute_method(self, method_name, kwargs):
        if self.passive:
            raise RuntimeError("This plugin is passive (aka does not implement main.py)")
        async with self.method_call_lock:
            await self._open_socket_if_not_exists()
            self.writer.write(
                (dumps({"method": method_name, "args": kwargs})+"\n").encode("utf-8"))
            await self.writer.drain()
            res = loads((await self.reader.readline()).decode("utf-8"))
            if not res["success"]:
                raise Exception(res["res"])
            return res["res"]