maubot/maubot/loader/zip.py
2018-10-14 22:57:11 +03:00

144 lines
5.3 KiB
Python

# maubot - A plugin-based Matrix bot system.
# Copyright (C) 2018 Tulir Asokan
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from typing import Dict, List, Type
from zipfile import ZipFile, BadZipFile
import sys
import configparser
from ..lib.zipimport import zipimporter, ZipImportError
from ..plugin_base import Plugin
from .abc import PluginLoader, PluginClass
class MaubotZipImportError(Exception):
pass
class ZippedPluginLoader(PluginLoader):
path_cache: Dict[str, 'ZippedPluginLoader'] = {}
id_cache: Dict[str, 'ZippedPluginLoader'] = {}
path: str
id: str
version: str
modules: List[str]
main_class: str
main_module: str
loaded: bool
_importer: zipimporter
def __init__(self, path: str) -> None:
self.path = path
self.id = None
self.loaded = False
self._load_meta()
self._run_preload_checks(self._get_importer())
self.path_cache[self.path] = self
self.id_cache[self.id] = self
def __repr__(self) -> str:
return ("<ZippedPlugin "
f"path='{self.path}' "
f"id='{self.id}' "
f"loaded={self.loaded}>")
def _load_meta(self) -> None:
try:
file = ZipFile(self.path)
data = file.read("maubot.ini")
except FileNotFoundError as e:
raise MaubotZipImportError(f"Maubot plugin not found at {self.path}") from e
except BadZipFile as e:
raise MaubotZipImportError(f"File at {self.path} is not a maubot plugin") from e
except KeyError as e:
raise MaubotZipImportError(
"File at {path} does not contain a maubot plugin definition") from e
config = configparser.ConfigParser()
try:
config.read_string(data.decode("utf-8"), source=f"{self.path}/maubot.ini")
meta = config["maubot"]
meta_id = meta["ID"]
version = meta["Version"]
modules = [mod.strip() for mod in meta["Modules"].split(",")]
main_class = meta["MainClass"]
main_module = modules[-1]
if "/" in main_class:
main_module, main_class = main_class.split("/")[:2]
except (configparser.Error, KeyError, IndexError, ValueError) as e:
raise MaubotZipImportError(
f"Maubot plugin definition in file at {self.path} is invalid") from e
if self.id and meta_id != self.id:
raise MaubotZipImportError("Maubot plugin ID changed during reload")
self.id, self.version, self.modules = meta_id, version, modules
self.main_class, self.main_module = main_class, main_module
def _get_importer(self, reset_cache: bool = False) -> zipimporter:
try:
importer = zipimporter(self.path)
if reset_cache:
importer.reset_cache()
return importer
except ZipImportError as e:
raise MaubotZipImportError(
f"File at {self.path} not found or not a maubot plugin") from e
def _run_preload_checks(self, importer: zipimporter) -> None:
try:
code = importer.get_code(self.main_module.replace(".", "/"))
if self.main_class not in code.co_names:
raise MaubotZipImportError(
f"Main class {self.main_class} not in {self.main_module}")
except ZipImportError as e:
raise MaubotZipImportError(
f"Main module {self.main_module} not found in {self.path}") from e
for module in self.modules:
try:
importer.find_module(module)
except ZipImportError as e:
raise MaubotZipImportError(f"Module {module} not found in {self.path}") from e
def load(self) -> Type[PluginClass]:
importer = self._get_importer(reset_cache=self.loaded)
self._run_preload_checks(importer)
for module in self.modules:
importer.load_module(module)
self.loaded = True
main_mod = sys.modules[self.main_module]
plugin = getattr(main_mod, self.main_class)
if not issubclass(plugin, Plugin):
raise MaubotZipImportError(
f"Main class of plugin at {self.path} does not extend maubot.Plugin")
return plugin
def reload(self) -> Type[PluginClass]:
self.unload()
return self.load()
def unload(self) -> None:
for name, mod in list(sys.modules.items()):
if getattr(mod, "__file__", "").startswith(self.path):
del sys.modules[name]
def destroy(self) -> None:
self.unload()
try:
del self.path_cache[self.path]
except KeyError:
pass
try:
del self.id_cache[self.id]
except KeyError:
pass