diff options
Diffstat (limited to 'lib/sqlalchemy/util/langhelpers.py')
| -rw-r--r-- | lib/sqlalchemy/util/langhelpers.py | 155 |
1 files changed, 147 insertions, 8 deletions
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py index e546f196d..4289db812 100644 --- a/lib/sqlalchemy/util/langhelpers.py +++ b/lib/sqlalchemy/util/langhelpers.py @@ -9,6 +9,7 @@ modules, classes, hierarchies, attributes, functions, and methods. """ + from functools import update_wrapper import hashlib import inspect @@ -462,6 +463,8 @@ def format_argspec_plus(fn, grouped=True): passed positionally. apply_kw Like apply_pos, except keyword-ish args are passed as keywords. + apply_pos_proxied + Like apply_pos but omits the self/cls argument Example:: @@ -478,16 +481,27 @@ def format_argspec_plus(fn, grouped=True): spec = fn args = compat.inspect_formatargspec(*spec) + + apply_pos = compat.inspect_formatargspec( + spec[0], spec[1], spec[2], None, spec[4] + ) + if spec[0]: self_arg = spec[0][0] + + apply_pos_proxied = compat.inspect_formatargspec( + spec[0][1:], spec[1], spec[2], None, spec[4] + ) + elif spec[1]: + # im not sure what this is self_arg = "%s[0]" % spec[1] + + apply_pos_proxied = apply_pos else: self_arg = None + apply_pos_proxied = apply_pos - apply_pos = compat.inspect_formatargspec( - spec[0], spec[1], spec[2], None, spec[4] - ) num_defaults = 0 if spec[3]: num_defaults += len(spec[3]) @@ -513,6 +527,7 @@ def format_argspec_plus(fn, grouped=True): self_arg=self_arg, apply_pos=apply_pos, apply_kw=apply_kw, + apply_pos_proxied=apply_pos_proxied, ) else: return dict( @@ -520,6 +535,7 @@ def format_argspec_plus(fn, grouped=True): self_arg=self_arg, apply_pos=apply_pos[1:-1], apply_kw=apply_kw[1:-1], + apply_pos_proxied=apply_pos_proxied[1:-1], ) @@ -534,17 +550,140 @@ def format_argspec_init(method, grouped=True): """ if method is object.__init__: - args = grouped and "(self)" or "self" + args = "(self)" if grouped else "self" + proxied = "()" if grouped else "" else: try: return format_argspec_plus(method, grouped=grouped) except TypeError: args = ( - grouped - and "(self, *args, **kwargs)" - or "self, *args, **kwargs" + "(self, *args, **kwargs)" + if grouped + else "self, *args, **kwargs" ) - return dict(self_arg="self", args=args, apply_pos=args, apply_kw=args) + proxied = "(*args, **kwargs)" if grouped else "*args, **kwargs" + return dict( + self_arg="self", + args=args, + apply_pos=args, + apply_kw=args, + apply_pos_proxied=proxied, + ) + + +def create_proxy_methods( + target_cls, + target_cls_sphinx_name, + proxy_cls_sphinx_name, + classmethods=(), + methods=(), + attributes=(), +): + """A class decorator that will copy attributes to a proxy class. + + The class to be instrumented must define a single accessor "_proxied". + + """ + + def decorate(cls): + def instrument(name, clslevel=False): + fn = getattr(target_cls, name) + spec = compat.inspect_getfullargspec(fn) + env = {} + + spec = _update_argspec_defaults_into_env(spec, env) + caller_argspec = format_argspec_plus(spec, grouped=False) + + metadata = { + "name": fn.__name__, + "apply_pos_proxied": caller_argspec["apply_pos_proxied"], + "args": caller_argspec["args"], + "self_arg": caller_argspec["self_arg"], + } + + if clslevel: + code = ( + "def %(name)s(%(args)s):\n" + " return target_cls.%(name)s(%(apply_pos_proxied)s)" + % metadata + ) + env["target_cls"] = target_cls + else: + code = ( + "def %(name)s(%(args)s):\n" + " return %(self_arg)s._proxied.%(name)s(%(apply_pos_proxied)s)" # noqa E501 + % metadata + ) + + proxy_fn = _exec_code_in_env(code, env, fn.__name__) + proxy_fn.__defaults__ = getattr(fn, "__func__", fn).__defaults__ + proxy_fn.__doc__ = inject_docstring_text( + fn.__doc__, + ".. container:: class_bases\n\n " + "Proxied for the %s class on behalf of the %s class." + % (target_cls_sphinx_name, proxy_cls_sphinx_name), + 1, + ) + + if clslevel: + proxy_fn = classmethod(proxy_fn) + + return proxy_fn + + def makeprop(name): + attr = target_cls.__dict__.get(name, None) + + if attr is not None: + doc = inject_docstring_text( + attr.__doc__, + ".. container:: class_bases\n\n " + "Proxied for the %s class on behalf of the %s class." + % ( + target_cls_sphinx_name, + proxy_cls_sphinx_name, + ), + 1, + ) + else: + doc = None + + code = ( + "def set_(self, attr):\n" + " self._proxied.%(name)s = attr\n" + "def get(self):\n" + " return self._proxied.%(name)s\n" + "get.__doc__ = doc\n" + "getset = property(get, set_)" + ) % {"name": name} + + getset = _exec_code_in_env(code, {"doc": doc}, "getset") + + return getset + + for meth in methods: + if hasattr(cls, meth): + raise TypeError( + "class %s already has a method %s" % (cls, meth) + ) + setattr(cls, meth, instrument(meth)) + + for prop in attributes: + if hasattr(cls, prop): + raise TypeError( + "class %s already has a method %s" % (cls, prop) + ) + setattr(cls, prop, makeprop(prop)) + + for prop in classmethods: + if hasattr(cls, prop): + raise TypeError( + "class %s already has a method %s" % (cls, prop) + ) + setattr(cls, prop, instrument(prop, clslevel=True)) + + return cls + + return decorate def getargspec_init(method): |