"""本模块实现插件加载流程。 参考: [import hooks](https://docs.python.org/3/reference/import.html#import-hooks), [PEP302](https://www.python.org/dev/peps/pep-0302/) FrontMatter: sidebar_position: 5 description: nonebot.plugin.manager 模块 """ import sys import pkgutil import importlib from pathlib import Path from itertools import chain from types import ModuleType from importlib.abc import MetaPathFinder from importlib.machinery import PathFinder, SourceFileLoader from typing import Set, Dict, List, Iterable, Optional, Sequence from nonebot.log import logger from nonebot.utils import escape_tag, path_to_module_name from .model import Plugin, PluginMetadata from . import ( _managers, _new_plugin, _revert_plugin, _current_plugin_chain, _module_name_to_plugin_name, ) class PluginManager: """插件管理器。 参数: plugins: 独立插件模块名集合。 search_path: 插件搜索路径（文件夹）。 """ def __init__( self, plugins: Optional[Iterable[str]] = None, search_path: Optional[Iterable[str]] = None, ): # simple plugin not in search path self.plugins: Set[str] = set(plugins or []) self.search_path: Set[str] = set(search_path or []) # cache plugins self._third_party_plugin_names: Dict[str, str] = {} self._searched_plugin_names: Dict[str, Path] = {} self.prepare_plugins() def __repr__(self) -> str: return f"PluginManager(plugins={self.plugins}, search_path={self.search_path})" @property def third_party_plugins(self) -> Set[str]: """返回所有独立插件名称。""" return set(self._third_party_plugin_names.keys()) @property def searched_plugins(self) -> Set[str]: """返回已搜索到的插件名称。""" return set(self._searched_plugin_names.keys()) @property def available_plugins(self) -> Set[str]: """返回当前插件管理器中可用的插件名称。""" return self.third_party_plugins | self.searched_plugins def _previous_plugins(self) -> Set[str]: _pre_managers: List[PluginManager] if self in _managers: _pre_managers = _managers[: _managers.index(self)] else: _pre_managers = _managers[:] return { *chain.from_iterable(manager.available_plugins for manager in _pre_managers) } def prepare_plugins(self) -> Set[str]: """搜索插件并缓存插件名称。""" # get all previous ready to load plugins previous_plugins = self._previous_plugins() searched_plugins: Dict[str, Path] = {} third_party_plugins: Dict[str, str] = {} # check third party plugins for plugin in self.plugins: name = _module_name_to_plugin_name(plugin) if name in third_party_plugins or name in previous_plugins: raise RuntimeError( f"Plugin already exists: {name}! Check your plugin name" ) third_party_plugins[name] = plugin self._third_party_plugin_names = third_party_plugins # check plugins in search path for module_info in pkgutil.iter_modules(self.search_path): # ignore if startswith "_" if module_info.name.startswith("_"): continue if ( module_info.name in searched_plugins or module_info.name in previous_plugins or module_info.name in third_party_plugins ): raise RuntimeError( f"Plugin already exists: {module_info.name}! Check your plugin name" ) if not ( module_spec := module_info.module_finder.find_spec( module_info.name, None ) ): continue if not (module_path := module_spec.origin): continue searched_plugins[module_info.name] = Path(module_path).resolve() self._searched_plugin_names = searched_plugins return self.available_plugins def load_plugin(self, name: str) -> Optional[Plugin]: """加载指定插件。 对于独立插件，可以使用完整插件模块名或者插件名称。 参数: name: 插件名称。 """ try: if name in self.plugins: module = importlib.import_module(name) elif name in self._third_party_plugin_names: module = importlib.import_module(self._third_party_plugin_names[name]) elif name in self._searched_plugin_names: module = importlib.import_module( path_to_module_name(self._searched_plugin_names[name]) ) else: raise RuntimeError(f"Plugin not found: {name}! Check your plugin name") if ( plugin := getattr(module, "__plugin__", None) ) is None or not isinstance(plugin, Plugin): raise RuntimeError( f"Module {module.__name__} is not loaded as a plugin! " "Make sure not to import it before loading." ) logger.opt(colors=True).success( f'Succeeded to load plugin "{escape_tag(plugin.name)}"' + ( f' from "{escape_tag(plugin.module_name)}"' if plugin.module_name != plugin.name else "" ) ) return plugin except Exception as e: logger.opt(colors=True, exception=e).error( f'Failed to import "{escape_tag(name)}"' ) def load_all_plugins(self) -> Set[Plugin]: """加载所有可用插件。""" return set( filter(None, (self.load_plugin(name) for name in self.available_plugins)) ) class PluginFinder(MetaPathFinder): def find_spec( self, fullname: str, path: Optional[Sequence[str]], target: Optional[ModuleType] = None, ): if _managers: module_spec = PathFinder.find_spec(fullname, path, target) if not module_spec: return module_origin = module_spec.origin if not module_origin: return module_path = Path(module_origin).resolve() for manager in reversed(_managers): # use path instead of name in case of submodule name conflict if ( fullname in manager.plugins or module_path in manager._searched_plugin_names.values() ): module_spec.loader = PluginLoader(manager, fullname, module_origin) return module_spec return class PluginLoader(SourceFileLoader): def __init__(self, manager: PluginManager, fullname: str, path) -> None: self.manager = manager self.loaded = False super().__init__(fullname, path) def create_module(self, spec) -> Optional[ModuleType]: if self.name in sys.modules: self.loaded = True return sys.modules[self.name] # return None to use default module creation return super().create_module(spec) def exec_module(self, module: ModuleType) -> None: if self.loaded: return # create plugin before executing plugin = _new_plugin(self.name, module, self.manager) setattr(module, "__plugin__", plugin) # detect parent plugin before entering current plugin context parent_plugins = _current_plugin_chain.get() for pre_plugin in reversed(parent_plugins): # ensure parent plugin is declared before current plugin if _managers.index(pre_plugin.manager) < _managers.index(self.manager): plugin.parent_plugin = pre_plugin pre_plugin.sub_plugins.add(plugin) break # enter plugin context _plugin_token = _current_plugin_chain.set((*parent_plugins, plugin)) try: super().exec_module(module) except Exception: _revert_plugin(plugin) raise finally: # leave plugin context _current_plugin_chain.reset(_plugin_token) # get plugin metadata metadata: Optional[PluginMetadata] = getattr(module, "__plugin_meta__", None) plugin.metadata = metadata return sys.meta_path.insert(0, PluginFinder())