celery/celery/__compat__.py

from __future__ import absolute_import

import operator
import sys

from importlib import import_module
from types import ModuleType

from .local import Proxy

MODULE_DEPRECATED = """
The module %s is deprecated and will be removed in a future version.
"""

DEFAULT_ATTRS = set(["__file__", "__path__", "__doc__", "__all__"])

# im_func is no longer available in Py3.
# instead the unbound method itself can be used.
if sys.version_info[0] == 3:  # pragma: no cover
    def fun_of_method(method):
        return method
else:
    def fun_of_method(method):  # noqa
        return method.im_func


def getappattr(path):
    """Gets attribute from the current_app recursively,
    e.g. getappattr("amqp.get_task_consumer")``."""
    from celery import current_app
    return current_app._rgetattr(path)


def _compat_task_decorator(*args, **kwargs):
    from celery import current_app
    kwargs.setdefault("accept_magic_kwargs", True)
    return current_app.task(*args, **kwargs)


def _compat_periodic_task_decorator(*args, **kwargs):
    from celery.task import periodic_task
    kwargs.setdefault("accept_magic_kwargs", True)
    return periodic_task(*args, **kwargs)


COMPAT_MODULES = {
    "celery": {
        "execute": {
            "send_task": "send_task",
        },
        "decorators": {
            "task": _compat_task_decorator,
            "periodic_task": _compat_periodic_task_decorator,
        },
        "log": {
            "get_default_logger": "log.get_default_logger",
            "setup_logger": "log.setup_logger",
            "setup_loggig_subsystem": "log.setup_logging_subsystem",
            "redirect_stdouts_to_logger": "log.redirect_stdouts_to_logger",
        },
        "messaging": {
            "TaskPublisher": "amqp.TaskPublisher",
            "TaskConsumer": "amqp.TaskConsumer",
            "establish_connection": "broker_connection",
            "with_connection": "with_default_connection",
            "get_consumer_set": "amqp.TaskConsumer",
        },
        "registry": {
            "tasks": "tasks",
        },
    },
    "celery.task": {
        "control": {
            "broadcast": "control.broadcast",
            "rate_limit": "control.rate_limit",
            "time_limit": "control.time_limit",
            "ping": "control.ping",
            "revoke": "control.revoke",
            "discard_all": "control.purge",
            "inspect": "control.inspect",
        },
        "schedules": "celery.schedules",
        "chords": "celery.canvas",
    }
}


class class_property(object):

    def __init__(self, fget=None, fset=None):
        assert fget and isinstance(fget, classmethod)
        assert isinstance(fset, classmethod) if fset else True
        self.__get = fget
        self.__set = fset

        info = fget.__get__(object)  # just need the info attrs.
        self.__doc__ = info.__doc__
        self.__name__ = info.__name__
        self.__module__ = info.__module__

    def __get__(self, obj, type=None):
        if obj and type is None:
            type = obj.__class__
        return self.__get.__get__(obj, type)()

    def __set__(self, obj, value):
        if obj is None:
            return self
        return self.__set.__get__(obj)(value)


def reclassmethod(method):
    return classmethod(fun_of_method(method))


class MagicModule(ModuleType):
    _compat_modules = ()
    _all_by_module = {}
    _direct = {}
    _object_origins = {}

    def __getattr__(self, name):
        if name in self._object_origins:
            module = __import__(self._object_origins[name], None, None, [name])
            for item in self._all_by_module[module.__name__]:
                setattr(self, item, getattr(module, item))
            return getattr(module, name)
        elif name in self._direct:
            module = __import__(self._direct[name], None, None, [name])
            setattr(self, name, module)
            return module
        return ModuleType.__getattribute__(self, name)

    def __dir__(self):
        return list(set(self.__all__) | DEFAULT_ATTRS)


def create_module(name, attrs, cls_attrs=None, pkg=None, base=MagicModule,
        prepare_attr=None):
    fqdn = '.'.join([pkg.__name__, name]) if pkg else name
    cls_attrs = {} if cls_attrs is None else cls_attrs

    attrs = dict((attr_name, prepare_attr(attr) if prepare_attr else attr)
                    for attr_name, attr in attrs.iteritems())
    module = sys.modules[fqdn] = type(name, (base, ), cls_attrs)(fqdn)
    module.__dict__.update(attrs)
    return module


def recreate_module(name, compat_modules=(), by_module={}, direct={},
        base=MagicModule, **attrs):
    old_module = sys.modules[name]
    origins = get_origins(by_module)
    compat_modules = COMPAT_MODULES.get(name, ())

    cattrs = dict(_compat_modules=compat_modules,
                  _all_by_module=by_module, _direct=direct,
                  _object_origins=origins,
                  __all__=tuple(set(reduce(operator.add, map(tuple, [
                                compat_modules, origins, direct, attrs])))))
    new_module = create_module(name, attrs, cls_attrs=cattrs, base=base)
    new_module.__dict__.update(dict((mod, get_compat_module(new_module, mod))
                                     for mod in compat_modules))
    return old_module, new_module


def get_compat_module(pkg, name):

    def prepare(attr):
        if isinstance(attr, basestring):
            return Proxy(getappattr, (attr, ))
        return attr

    attrs = COMPAT_MODULES[pkg.__name__][name]
    if isinstance(attrs, basestring):
        fqdn = '.'.join([pkg.__name__, name])
        module = sys.modules[fqdn] = import_module(attrs)
        return module
    attrs["__all__"] = attrs.keys()
    return create_module(name, dict(attrs), pkg=pkg, prepare_attr=prepare)


def get_origins(defs):
    origins = {}
    for module, items in defs.iteritems():
        origins.update(dict((item, module) for item in items))
    return origins