--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.9/site-packages/pluggy/manager.py	Mon Mar 22 18:12:50 2021 +0000
@@ -0,0 +1,394 @@
+import inspect
+import sys
+from . import _tracing
+from .callers import _Result
+from .hooks import HookImpl, _HookRelay, _HookCaller, normalize_hookimpl_opts
+import warnings
+
+if sys.version_info >= (3, 8):
+    from importlib import metadata as importlib_metadata
+else:
+    import importlib_metadata
+
+
+def _warn_for_function(warning, function):
+    warnings.warn_explicit(
+        warning,
+        type(warning),
+        lineno=function.__code__.co_firstlineno,
+        filename=function.__code__.co_filename,
+    )
+
+
+class PluginValidationError(Exception):
+    """ plugin failed validation.
+
+    :param object plugin: the plugin which failed validation,
+        may be a module or an arbitrary object.
+    """
+
+    def __init__(self, plugin, message):
+        self.plugin = plugin
+        super(Exception, self).__init__(message)
+
+
+class DistFacade(object):
+    """Emulate a pkg_resources Distribution"""
+
+    def __init__(self, dist):
+        self._dist = dist
+
+    @property
+    def project_name(self):
+        return self.metadata["name"]
+
+    def __getattr__(self, attr, default=None):
+        return getattr(self._dist, attr, default)
+
+    def __dir__(self):
+        return sorted(dir(self._dist) + ["_dist", "project_name"])
+
+
+class PluginManager(object):
+    """ Core :py:class:`.PluginManager` class which manages registration
+    of plugin objects and 1:N hook calling.
+
+    You can register new hooks by calling :py:meth:`add_hookspecs(module_or_class)
+    <.PluginManager.add_hookspecs>`.
+    You can register plugin objects (which contain hooks) by calling
+    :py:meth:`register(plugin) <.PluginManager.register>`.  The :py:class:`.PluginManager`
+    is initialized with a prefix that is searched for in the names of the dict
+    of registered plugin objects.
+
+    For debugging purposes you can call :py:meth:`.PluginManager.enable_tracing`
+    which will subsequently send debug information to the trace helper.
+    """
+
+    def __init__(self, project_name, implprefix=None):
+        """If ``implprefix`` is given implementation functions
+        will be recognized if their name matches the ``implprefix``. """
+        self.project_name = project_name
+        self._name2plugin = {}
+        self._plugin2hookcallers = {}
+        self._plugin_distinfo = []
+        self.trace = _tracing.TagTracer().get("pluginmanage")
+        self.hook = _HookRelay()
+        if implprefix is not None:
+            warnings.warn(
+                "Support for the `implprefix` arg is now deprecated and will "
+                "be removed in an upcoming release. Please use HookimplMarker.",
+                DeprecationWarning,
+                stacklevel=2,
+            )
+        self._implprefix = implprefix
+        self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
+            methods,
+            kwargs,
+            firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
+        )
+
+    def _hookexec(self, hook, methods, kwargs):
+        # called from all hookcaller instances.
+        # enable_tracing will set its own wrapping function at self._inner_hookexec
+        return self._inner_hookexec(hook, methods, kwargs)
+
+    def register(self, plugin, name=None):
+        """ Register a plugin and return its canonical name or ``None`` if the name
+        is blocked from registering.  Raise a :py:class:`ValueError` if the plugin
+        is already registered. """
+        plugin_name = name or self.get_canonical_name(plugin)
+
+        if plugin_name in self._name2plugin or plugin in self._plugin2hookcallers:
+            if self._name2plugin.get(plugin_name, -1) is None:
+                return  # blocked plugin, return None to indicate no registration
+            raise ValueError(
+                "Plugin already registered: %s=%s\n%s"
+                % (plugin_name, plugin, self._name2plugin)
+            )
+
+        # XXX if an error happens we should make sure no state has been
+        # changed at point of return
+        self._name2plugin[plugin_name] = plugin
+
+        # register matching hook implementations of the plugin
+        self._plugin2hookcallers[plugin] = hookcallers = []
+        for name in dir(plugin):
+            hookimpl_opts = self.parse_hookimpl_opts(plugin, name)
+            if hookimpl_opts is not None:
+                normalize_hookimpl_opts(hookimpl_opts)
+                method = getattr(plugin, name)
+                hookimpl = HookImpl(plugin, plugin_name, method, hookimpl_opts)
+                hook = getattr(self.hook, name, None)
+                if hook is None:
+                    hook = _HookCaller(name, self._hookexec)
+                    setattr(self.hook, name, hook)
+                elif hook.has_spec():
+                    self._verify_hook(hook, hookimpl)
+                    hook._maybe_apply_history(hookimpl)
+                hook._add_hookimpl(hookimpl)
+                hookcallers.append(hook)
+        return plugin_name
+
+    def parse_hookimpl_opts(self, plugin, name):
+        method = getattr(plugin, name)
+        if not inspect.isroutine(method):
+            return
+        try:
+            res = getattr(method, self.project_name + "_impl", None)
+        except Exception:
+            res = {}
+        if res is not None and not isinstance(res, dict):
+            # false positive
+            res = None
+        # TODO: remove when we drop implprefix in 1.0
+        elif res is None and self._implprefix and name.startswith(self._implprefix):
+            _warn_for_function(
+                DeprecationWarning(
+                    "The `implprefix` system is deprecated please decorate "
+                    "this function using an instance of HookimplMarker."
+                ),
+                method,
+            )
+            res = {}
+        return res
+
+    def unregister(self, plugin=None, name=None):
+        """ unregister a plugin object and all its contained hook implementations
+        from internal data structures. """
+        if name is None:
+            assert plugin is not None, "one of name or plugin needs to be specified"
+            name = self.get_name(plugin)
+
+        if plugin is None:
+            plugin = self.get_plugin(name)
+
+        # if self._name2plugin[name] == None registration was blocked: ignore
+        if self._name2plugin.get(name):
+            del self._name2plugin[name]
+
+        for hookcaller in self._plugin2hookcallers.pop(plugin, []):
+            hookcaller._remove_plugin(plugin)
+
+        return plugin
+
+    def set_blocked(self, name):
+        """ block registrations of the given name, unregister if already registered. """
+        self.unregister(name=name)
+        self._name2plugin[name] = None
+
+    def is_blocked(self, name):
+        """ return ``True`` if the given plugin name is blocked. """
+        return name in self._name2plugin and self._name2plugin[name] is None
+
+    def add_hookspecs(self, module_or_class):
+        """ add new hook specifications defined in the given ``module_or_class``.
+        Functions are recognized if they have been decorated accordingly. """
+        names = []
+        for name in dir(module_or_class):
+            spec_opts = self.parse_hookspec_opts(module_or_class, name)
+            if spec_opts is not None:
+                hc = getattr(self.hook, name, None)
+                if hc is None:
+                    hc = _HookCaller(name, self._hookexec, module_or_class, spec_opts)
+                    setattr(self.hook, name, hc)
+                else:
+                    # plugins registered this hook without knowing the spec
+                    hc.set_specification(module_or_class, spec_opts)
+                    for hookfunction in hc.get_hookimpls():
+                        self._verify_hook(hc, hookfunction)
+                names.append(name)
+
+        if not names:
+            raise ValueError(
+                "did not find any %r hooks in %r" % (self.project_name, module_or_class)
+            )
+
+    def parse_hookspec_opts(self, module_or_class, name):
+        method = getattr(module_or_class, name)
+        return getattr(method, self.project_name + "_spec", None)
+
+    def get_plugins(self):
+        """ return the set of registered plugins. """
+        return set(self._plugin2hookcallers)
+
+    def is_registered(self, plugin):
+        """ Return ``True`` if the plugin is already registered. """
+        return plugin in self._plugin2hookcallers
+
+    def get_canonical_name(self, plugin):
+        """ Return canonical name for a plugin object. Note that a plugin
+        may be registered under a different name which was specified
+        by the caller of :py:meth:`register(plugin, name) <.PluginManager.register>`.
+        To obtain the name of an registered plugin use :py:meth:`get_name(plugin)
+        <.PluginManager.get_name>` instead."""
+        return getattr(plugin, "__name__", None) or str(id(plugin))
+
+    def get_plugin(self, name):
+        """ Return a plugin or ``None`` for the given name. """
+        return self._name2plugin.get(name)
+
+    def has_plugin(self, name):
+        """ Return ``True`` if a plugin with the given name is registered. """
+        return self.get_plugin(name) is not None
+
+    def get_name(self, plugin):
+        """ Return name for registered plugin or ``None`` if not registered. """
+        for name, val in self._name2plugin.items():
+            if plugin == val:
+                return name
+
+    def _verify_hook(self, hook, hookimpl):
+        if hook.is_historic() and hookimpl.hookwrapper:
+            raise PluginValidationError(
+                hookimpl.plugin,
+                "Plugin %r\nhook %r\nhistoric incompatible to hookwrapper"
+                % (hookimpl.plugin_name, hook.name),
+            )
+        if hook.spec.warn_on_impl:
+            _warn_for_function(hook.spec.warn_on_impl, hookimpl.function)
+        # positional arg checking
+        notinspec = set(hookimpl.argnames) - set(hook.spec.argnames)
+        if notinspec:
+            raise PluginValidationError(
+                hookimpl.plugin,
+                "Plugin %r for hook %r\nhookimpl definition: %s\n"
+                "Argument(s) %s are declared in the hookimpl but "
+                "can not be found in the hookspec"
+                % (
+                    hookimpl.plugin_name,
+                    hook.name,
+                    _formatdef(hookimpl.function),
+                    notinspec,
+                ),
+            )
+
+    def check_pending(self):
+        """ Verify that all hooks which have not been verified against
+        a hook specification are optional, otherwise raise :py:class:`.PluginValidationError`."""
+        for name in self.hook.__dict__:
+            if name[0] != "_":
+                hook = getattr(self.hook, name)
+                if not hook.has_spec():
+                    for hookimpl in hook.get_hookimpls():
+                        if not hookimpl.optionalhook:
+                            raise PluginValidationError(
+                                hookimpl.plugin,
+                                "unknown hook %r in plugin %r"
+                                % (name, hookimpl.plugin),
+                            )
+
+    def load_setuptools_entrypoints(self, group, name=None):
+        """ Load modules from querying the specified setuptools ``group``.
+
+        :param str group: entry point group to load plugins
+        :param str name: if given, loads only plugins with the given ``name``.
+        :rtype: int
+        :return: return the number of loaded plugins by this call.
+        """
+        count = 0
+        for dist in importlib_metadata.distributions():
+            for ep in dist.entry_points:
+                if (
+                    ep.group != group
+                    or (name is not None and ep.name != name)
+                    # already registered
+                    or self.get_plugin(ep.name)
+                    or self.is_blocked(ep.name)
+                ):
+                    continue
+                plugin = ep.load()
+                self.register(plugin, name=ep.name)
+                self._plugin_distinfo.append((plugin, DistFacade(dist)))
+                count += 1
+        return count
+
+    def list_plugin_distinfo(self):
+        """ return list of distinfo/plugin tuples for all setuptools registered
+        plugins. """
+        return list(self._plugin_distinfo)
+
+    def list_name_plugin(self):
+        """ return list of name/plugin pairs. """
+        return list(self._name2plugin.items())
+
+    def get_hookcallers(self, plugin):
+        """ get all hook callers for the specified plugin. """
+        return self._plugin2hookcallers.get(plugin)
+
+    def add_hookcall_monitoring(self, before, after):
+        """ add before/after tracing functions for all hooks
+        and return an undo function which, when called,
+        will remove the added tracers.
+
+        ``before(hook_name, hook_impls, kwargs)`` will be called ahead
+        of all hook calls and receive a hookcaller instance, a list
+        of HookImpl instances and the keyword arguments for the hook call.
+
+        ``after(outcome, hook_name, hook_impls, kwargs)`` receives the
+        same arguments as ``before`` but also a :py:class:`pluggy.callers._Result` object
+        which represents the result of the overall hook call.
+        """
+        oldcall = self._inner_hookexec
+
+        def traced_hookexec(hook, hook_impls, kwargs):
+            before(hook.name, hook_impls, kwargs)
+            outcome = _Result.from_call(lambda: oldcall(hook, hook_impls, kwargs))
+            after(outcome, hook.name, hook_impls, kwargs)
+            return outcome.get_result()
+
+        self._inner_hookexec = traced_hookexec
+
+        def undo():
+            self._inner_hookexec = oldcall
+
+        return undo
+
+    def enable_tracing(self):
+        """ enable tracing of hook calls and return an undo function. """
+        hooktrace = self.trace.root.get("hook")
+
+        def before(hook_name, methods, kwargs):
+            hooktrace.root.indent += 1
+            hooktrace(hook_name, kwargs)
+
+        def after(outcome, hook_name, methods, kwargs):
+            if outcome.excinfo is None:
+                hooktrace("finish", hook_name, "-->", outcome.get_result())
+            hooktrace.root.indent -= 1
+
+        return self.add_hookcall_monitoring(before, after)
+
+    def subset_hook_caller(self, name, remove_plugins):
+        """ Return a new :py:class:`.hooks._HookCaller` instance for the named method
+        which manages calls to all registered plugins except the
+        ones from remove_plugins. """
+        orig = getattr(self.hook, name)
+        plugins_to_remove = [plug for plug in remove_plugins if hasattr(plug, name)]
+        if plugins_to_remove:
+            hc = _HookCaller(
+                orig.name, orig._hookexec, orig.spec.namespace, orig.spec.opts
+            )
+            for hookimpl in orig.get_hookimpls():
+                plugin = hookimpl.plugin
+                if plugin not in plugins_to_remove:
+                    hc._add_hookimpl(hookimpl)
+                    # we also keep track of this hook caller so it
+                    # gets properly removed on plugin unregistration
+                    self._plugin2hookcallers.setdefault(plugin, []).append(hc)
+            return hc
+        return orig
+
+
+if hasattr(inspect, "signature"):
+
+    def _formatdef(func):
+        return "%s%s" % (func.__name__, str(inspect.signature(func)))
+
+
+else:
+
+    def _formatdef(func):
+        return "%s%s" % (
+            func.__name__,
+            inspect.formatargspec(*inspect.getargspec(func)),
+        )