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Direktori : /opt/alt/python37/lib/python3.7/site-packages/alembic/util/ |
Current File : //opt/alt/python37/lib/python3.7/site-packages/alembic/util/langhelpers.py |
import textwrap import warnings import inspect import uuid import collections from .compat import callable, exec_, string_types, with_metaclass from sqlalchemy.util import format_argspec_plus, update_wrapper from sqlalchemy.util.compat import inspect_getfullargspec class _ModuleClsMeta(type): def __setattr__(cls, key, value): super(_ModuleClsMeta, cls).__setattr__(key, value) cls._update_module_proxies(key) class ModuleClsProxy(with_metaclass(_ModuleClsMeta)): """Create module level proxy functions for the methods on a given class. The functions will have a compatible signature as the methods. """ _setups = collections.defaultdict(lambda: (set(), [])) @classmethod def _update_module_proxies(cls, name): attr_names, modules = cls._setups[cls] for globals_, locals_ in modules: cls._add_proxied_attribute(name, globals_, locals_, attr_names) def _install_proxy(self): attr_names, modules = self._setups[self.__class__] for globals_, locals_ in modules: globals_['_proxy'] = self for attr_name in attr_names: globals_[attr_name] = getattr(self, attr_name) def _remove_proxy(self): attr_names, modules = self._setups[self.__class__] for globals_, locals_ in modules: globals_['_proxy'] = None for attr_name in attr_names: del globals_[attr_name] @classmethod def create_module_class_proxy(cls, globals_, locals_): attr_names, modules = cls._setups[cls] modules.append( (globals_, locals_) ) cls._setup_proxy(globals_, locals_, attr_names) @classmethod def _setup_proxy(cls, globals_, locals_, attr_names): for methname in dir(cls): cls._add_proxied_attribute(methname, globals_, locals_, attr_names) @classmethod def _add_proxied_attribute(cls, methname, globals_, locals_, attr_names): if not methname.startswith('_'): meth = getattr(cls, methname) if callable(meth): locals_[methname] = cls._create_method_proxy( methname, globals_, locals_) else: attr_names.add(methname) @classmethod def _create_method_proxy(cls, name, globals_, locals_): fn = getattr(cls, name) spec = inspect.getargspec(fn) if spec[0] and spec[0][0] == 'self': spec[0].pop(0) args = inspect.formatargspec(*spec) num_defaults = 0 if spec[3]: num_defaults += len(spec[3]) name_args = spec[0] if num_defaults: defaulted_vals = name_args[0 - num_defaults:] else: defaulted_vals = () apply_kw = inspect.formatargspec( name_args, spec[1], spec[2], defaulted_vals, formatvalue=lambda x: '=' + x) def _name_error(name): raise NameError( "Can't invoke function '%s', as the proxy object has " "not yet been " "established for the Alembic '%s' class. " "Try placing this code inside a callable." % ( name, cls.__name__ )) globals_['_name_error'] = _name_error translations = getattr(fn, "_legacy_translations", []) if translations: outer_args = inner_args = "*args, **kw" translate_str = "args, kw = _translate(%r, %r, %r, args, kw)" % ( fn.__name__, tuple(spec), translations ) def translate(fn_name, spec, translations, args, kw): return_kw = {} return_args = [] for oldname, newname in translations: if oldname in kw: warnings.warn( "Argument %r is now named %r " "for method %s()." % ( oldname, newname, fn_name )) return_kw[newname] = kw.pop(oldname) return_kw.update(kw) args = list(args) if spec[3]: pos_only = spec[0][:-len(spec[3])] else: pos_only = spec[0] for arg in pos_only: if arg not in return_kw: try: return_args.append(args.pop(0)) except IndexError: raise TypeError( "missing required positional argument: %s" % arg) return_args.extend(args) return return_args, return_kw globals_['_translate'] = translate else: outer_args = args[1:-1] inner_args = apply_kw[1:-1] translate_str = "" func_text = textwrap.dedent("""\ def %(name)s(%(args)s): %(doc)r %(translate)s try: p = _proxy except NameError: _name_error('%(name)s') return _proxy.%(name)s(%(apply_kw)s) e """ % { 'name': name, 'translate': translate_str, 'args': outer_args, 'apply_kw': inner_args, 'doc': fn.__doc__, }) lcl = {} exec_(func_text, globals_, lcl) return lcl[name] def _with_legacy_names(translations): def decorate(fn): fn._legacy_translations = translations return fn return decorate def asbool(value): return value is not None and \ value.lower() == 'true' def rev_id(): val = int(uuid.uuid4()) % 100000000000000 return hex(val)[2:-1] def to_list(x, default=None): if x is None: return default elif isinstance(x, string_types): return [x] elif isinstance(x, collections.Iterable): return list(x) else: return [x] def to_tuple(x, default=None): if x is None: return default elif isinstance(x, string_types): return (x, ) elif isinstance(x, collections.Iterable): return tuple(x) else: return (x, ) def unique_list(seq, hashfunc=None): seen = set() seen_add = seen.add if not hashfunc: return [x for x in seq if x not in seen and not seen_add(x)] else: return [x for x in seq if hashfunc(x) not in seen and not seen_add(hashfunc(x))] def dedupe_tuple(tup): return tuple(unique_list(tup)) class memoized_property(object): """A read-only @property that is only evaluated once.""" def __init__(self, fget, doc=None): self.fget = fget self.__doc__ = doc or fget.__doc__ self.__name__ = fget.__name__ def __get__(self, obj, cls): if obj is None: return self obj.__dict__[self.__name__] = result = self.fget(obj) return result class immutabledict(dict): def _immutable(self, *arg, **kw): raise TypeError("%s object is immutable" % self.__class__.__name__) __delitem__ = __setitem__ = __setattr__ = \ clear = pop = popitem = setdefault = \ update = _immutable def __new__(cls, *args): new = dict.__new__(cls) dict.__init__(new, *args) return new def __init__(self, *args): pass def __reduce__(self): return immutabledict, (dict(self), ) def union(self, d): if not self: return immutabledict(d) else: d2 = immutabledict(self) dict.update(d2, d) return d2 def __repr__(self): return "immutabledict(%s)" % dict.__repr__(self) class Dispatcher(object): def __init__(self, uselist=False): self._registry = {} self.uselist = uselist def dispatch_for(self, target, qualifier='default'): def decorate(fn): if self.uselist: self._registry.setdefault((target, qualifier), []).append(fn) else: assert (target, qualifier) not in self._registry self._registry[(target, qualifier)] = fn return fn return decorate def dispatch(self, obj, qualifier='default'): if isinstance(obj, string_types): targets = [obj] elif isinstance(obj, type): targets = obj.__mro__ else: targets = type(obj).__mro__ for spcls in targets: if qualifier != 'default' and (spcls, qualifier) in self._registry: return self._fn_or_list( self._registry[(spcls, qualifier)]) elif (spcls, 'default') in self._registry: return self._fn_or_list( self._registry[(spcls, 'default')]) else: raise ValueError("no dispatch function for object: %s" % obj) def _fn_or_list(self, fn_or_list): if self.uselist: def go(*arg, **kw): for fn in fn_or_list: fn(*arg, **kw) return go else: return fn_or_list def branch(self): """Return a copy of this dispatcher that is independently writable.""" d = Dispatcher() if self.uselist: d._registry.update( (k, [fn for fn in self._registry[k]]) for k in self._registry ) else: d._registry.update(self._registry) return d