#
# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import copy
import functools
import inspect
from polygraphy import config, mod
from polygraphy.logger import G_LOGGER
def make_iterable(obj):
return obj if type(obj) == tuple else (obj,)
[docs]@mod.export()
def extend(extend_func):
"""
A decorator that uses the function it decorates to extend the function
provided as a parameter.
This is best illustrated with an example:
::
def x(a0, a1, a2):
rv0 = [a0, a1, a2]
rv1 = None
return rv0, rv1
@extend(x)
def y(rv0, rv1):
rv0.append(-1)
# We can now call `y` as if it were `x`, and we will receive
# the return values from `x` after any modifications by `y`
rv0, rv1 = y(1, 2, 3)
assert rv0 == [1, 2, 3, -1]
assert rv1 is None
In this case, ``extend`` is essentially syntactic sugar for:
::
def y(a0, a1, a2):
rv0, rv1 = x(a0, a1, a2)
# Body of `y` from previous section
rv0.append(-1)
return rv0, rv1
If ``y`` does not return anything, or returns ``None``, then ``extend`` will
ensure that the return value of ``x`` is forwarded to the caller.
This means that ``y`` will provide exactly the same interface as ``x``.
If `y` returns something other than ``None``, then its return value will be
provided to the caller, and the return value of ``x`` will be discarded.
NOTE: This function will automatically unpack tuples returned by the function
being extended. Thus, the following implementation of ``x`` would behave just like
the one mentioned above:
::
def x(a0, a1, a2):
ret = (rv0, rv1)
return ret # Tuple will be unpacked, and `y` still sees 2 parameters
Args:
extend_func (Callable): A callable to extend.
"""
def extend_decorator(func):
@functools.wraps(func)
def extended_func(*args, **kwargs):
extend_func_retval = extend_func(*args, **kwargs)
extend_func_ret_tuple = make_iterable(extend_func_retval)
func_args = inspect.signature(func).parameters
# Special case for when the extended function does not return anything
if len(func_args) == 0 and len(extend_func_ret_tuple) == 1 and extend_func_ret_tuple[0] is None:
func_retval = func()
elif len(extend_func_ret_tuple) == len(func_args):
func_retval = func(*extend_func_ret_tuple)
else:
def try_get_name(fn):
try:
return fn.__name__
except:
return fn
G_LOGGER.critical(
"Function: {:} accepts {:} parameter(s), but "
"needs to accept {:} parameter(s) from: {:} instead.\nNote: Parameters should be: {:}".format(
try_get_name(func),
len(func_args),
len(extend_func_ret_tuple),
try_get_name(extend_func),
tuple(map(type, extend_func_ret_tuple)),
)
)
if func_retval is not None:
return func_retval
return extend_func_retval
return extended_func
return extend_decorator
@mod.export()
def constantmethod(func):
"""
A decorator that denotes constant methods.
NOTE: This decorator does nothing if the POLYGRAPHY_INTERNAL_CORRECTNESS_CHECKS environment variable is not set to `1`
Example:
::
class Dummy(object):
def __init__(self):
self.x = 1
@func.constantmethod
def modify_x(self):
self.x = 2
d = Dummy()
d.modify_x() # This will fail!
This provides only minimal protection against accidental mutation of instance attributes.
For example, if a class includes references (e.g. a numpy array member), this function cannot
ensure that the contents of that member (e.g. the values in a numpy array) will remain unchanged.
"""
if not config.INTERNAL_CORRECTNESS_CHECKS:
return func
@functools.wraps(func)
def wrapper(self, *args, **kwargs):
old_dict = copy.copy(vars(self))
ret = None
try:
ret = func(self, *args, **kwargs)
finally:
if vars(self) != old_dict:
G_LOGGER.internal_error(
"{:} was mutated in a constant method! Note:\nOld state: {:}\nNew state: {:}".format(
self, old_dict, vars(self)
)
)
return ret
return wrapper