diff options
Diffstat (limited to 'python/mach/mach/registrar.py')
| -rw-r--r-- | python/mach/mach/registrar.py | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/python/mach/mach/registrar.py b/python/mach/mach/registrar.py new file mode 100644 index 0000000000..a03590fddd --- /dev/null +++ b/python/mach/mach/registrar.py @@ -0,0 +1,205 @@ +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +import time +from cProfile import Profile +from pathlib import Path + +import six + +from .base import MachError + +INVALID_COMMAND_CONTEXT = r""" +It looks like you tried to run a mach command from an invalid context. The %s +command failed to meet the following conditions: %s + +Run |mach help| to show a list of all commands available to the current context. +""".lstrip() + + +class MachRegistrar(object): + """Container for mach command and config providers.""" + + def __init__(self): + self.command_handlers = {} + self.commands_by_category = {} + self.settings_providers = set() + self.categories = {} + self.require_conditions = False + self.command_depth = 0 + + def register_command_handler(self, handler): + name = handler.name + + if not handler.category: + raise MachError( + "Cannot register a mach command without a " "category: %s" % name + ) + + if handler.category not in self.categories: + raise MachError( + "Cannot register a command to an undefined " + "category: %s -> %s" % (name, handler.category) + ) + + self.command_handlers[name] = handler + self.commands_by_category[handler.category].add(name) + + def register_settings_provider(self, cls): + self.settings_providers.add(cls) + + def register_category(self, name, title, description, priority=50): + self.categories[name] = (title, description, priority) + self.commands_by_category[name] = set() + + @classmethod + def _condition_failed_message(cls, name, conditions): + msg = ["\n"] + for c in conditions: + part = [" %s" % getattr(c, "__name__", c)] + if c.__doc__ is not None: + part.append(c.__doc__) + msg.append(" - ".join(part)) + return INVALID_COMMAND_CONTEXT % (name, "\n".join(msg)) + + @classmethod + def _instance(_, handler, context, **kwargs): + if context is None: + raise ValueError("Expected a non-None context.") + + prerun = getattr(context, "pre_dispatch_handler", None) + if prerun: + prerun(context, handler, args=kwargs) + + context.handler = handler + return handler.create_instance(context, handler.virtualenv_name) + + @classmethod + def _fail_conditions(_, handler, instance): + fail_conditions = [] + if handler.conditions: + for c in handler.conditions: + if not c(instance): + fail_conditions.append(c) + + return fail_conditions + + def _run_command_handler( + self, + handler, + context, + command_site_manager=None, + debug_command=False, + profile_command=False, + **kwargs, + ): + instance = MachRegistrar._instance(handler, context, **kwargs) + fail_conditions = MachRegistrar._fail_conditions(handler, instance) + if fail_conditions: + print( + MachRegistrar._condition_failed_message(handler.name, fail_conditions) + ) + return 1 + + self.command_depth += 1 + fn = handler.func + if handler.virtualenv_name: + if command_site_manager: + instance.virtualenv_manager = command_site_manager + else: + instance.activate_virtualenv() + + profile = None + if profile_command: + profile = Profile() + profile.enable() + + start_time = time.monotonic() + + if debug_command: + import pdb + + result = pdb.runcall(fn, instance, **kwargs) + else: + result = fn(instance, **kwargs) + + end_time = time.monotonic() + + if profile_command: + profile.disable() + profile_file = ( + Path(context.topdir) / f"mach_profile_{handler.name}.cProfile" + ) + profile.dump_stats(profile_file) + print( + f'Mach command profile created at "{profile_file}". To visualize, use ' + f"snakeviz:" + ) + print("python3 -m pip install snakeviz") + print(f"python3 -m snakeviz {profile_file.name}") + + result = result or 0 + assert isinstance(result, six.integer_types) + + if not debug_command: + postrun = getattr(context, "post_dispatch_handler", None) + if postrun: + postrun( + context, + handler, + instance, + not result, + start_time, + end_time, + self.command_depth, + args=kwargs, + ) + self.command_depth -= 1 + + return result + + def dispatch(self, name, context, argv=None, subcommand=None, **kwargs): + """Dispatch/run a command. + + Commands can use this to call other commands. + """ + from mach.command_util import load_command_module_from_command_name + + handler = self.command_handlers.get(name) + + if not handler: + load_command_module_from_command_name(name, context.topdir) + handler = self.command_handlers.get(name) + if not handler: + raise MachError( + f"Mach was not able to load the module for the '{name}' command." + ) + + if subcommand: + handler = handler.subcommand_handlers[subcommand] + + if handler.parser: + parser = handler.parser + + # save and restore existing defaults so **kwargs don't persist across + # subsequent invocations of Registrar.dispatch() + old_defaults = parser._defaults.copy() + parser.set_defaults(**kwargs) + kwargs, unknown = parser.parse_known_args(argv or []) + kwargs = vars(kwargs) + parser._defaults = old_defaults + + if unknown: + if subcommand: + name = "{} {}".format(name, subcommand) + parser.error( + "unrecognized arguments for {}: {}".format( + name, ", ".join(["'{}'".format(arg) for arg in unknown]) + ) + ) + + return self._run_command_handler(handler, context, **kwargs) + + +Registrar = MachRegistrar() |