pytorch/test/package/test_model.py

199 lines
7.2 KiB
Python

# Owner(s): ["oncall: package/deploy"]
from io import BytesIO
from textwrap import dedent
from unittest import skipIf
import torch
from torch.package import PackageExporter, PackageImporter, sys_importer
from torch.testing._internal.common_utils import IS_FBCODE, IS_SANDCASTLE, run_tests
try:
from torchvision.models import resnet18
HAS_TORCHVISION = True
except ImportError:
HAS_TORCHVISION = False
skipIfNoTorchVision = skipIf(not HAS_TORCHVISION, "no torchvision")
try:
from .common import PackageTestCase
except ImportError:
# Support the case where we run this file directly.
from common import PackageTestCase
@skipIf(True, "Does not work with recent torchvision, see https://github.com/pytorch/pytorch/issues/81115")
@skipIfNoTorchVision
class ModelTest(PackageTestCase):
"""End-to-end tests packaging an entire model."""
@skipIf(
IS_FBCODE or IS_SANDCASTLE,
"Tests that use temporary files are disabled in fbcode",
)
def test_resnet(self):
resnet = resnet18()
f1 = self.temp()
# create a package that will save it along with its code
with PackageExporter(f1) as e:
# put the pickled resnet in the package, by default
# this will also save all the code files references by
# the objects in the pickle
e.intern("**")
e.save_pickle("model", "model.pkl", resnet)
# we can now load the saved model
i = PackageImporter(f1)
r2 = i.load_pickle("model", "model.pkl")
# test that it works
input = torch.rand(1, 3, 224, 224)
ref = resnet(input)
self.assertEqual(r2(input), ref)
# functions exist also to get at the private modules in each package
torchvision = i.import_module("torchvision")
f2 = BytesIO()
# if we are doing transfer learning we might want to re-save
# things that were loaded from a package.
# We need to tell the exporter about any modules that
# came from imported packages so that it can resolve
# class names like torchvision.models.resnet.ResNet
# to their source code.
with PackageExporter(f2, importer=(i, sys_importer)) as e:
# e.importers is a list of module importing functions
# that by default contains importlib.import_module.
# it is searched in order until the first success and
# that module is taken to be what torchvision.models.resnet
# should be in this code package. In the case of name collisions,
# such as trying to save a ResNet from two different packages,
# we take the first thing found in the path, so only ResNet objects from
# one importer will work. This avoids a bunch of name mangling in
# the source code. If you need to actually mix ResNet objects,
# we suggest reconstructing the model objects using code from a single package
# using functions like save_state_dict and load_state_dict to transfer state
# to the correct code objects.
e.intern("**")
e.save_pickle("model", "model.pkl", r2)
f2.seek(0)
i2 = PackageImporter(f2)
r3 = i2.load_pickle("model", "model.pkl")
self.assertEqual(r3(input), ref)
@skipIfNoTorchVision
def test_model_save(self):
# This example shows how you might package a model
# so that the creator of the model has flexibility about
# how they want to save it but the 'server' can always
# use the same API to load the package.
# The convension is for each model to provide a
# 'model' package with a 'load' function that actual
# reads the model out of the archive.
# How the load function is implemented is up to the
# the packager.
# get our normal torchvision resnet
resnet = resnet18()
f1 = BytesIO()
# Option 1: save by pickling the whole model
# + single-line, similar to torch.jit.save
# - more difficult to edit the code after the model is created
with PackageExporter(f1) as e:
e.intern("**")
e.save_pickle("model", "pickled", resnet)
# note that this source is the same for all models in this approach
# so it can be made part of an API that just takes the model and
# packages it with this source.
src = dedent(
"""\
import importlib
import torch_package_importer as resources
# server knows to call model.load() to get the model,
# maybe in the future it passes options as arguments by convension
def load():
return resources.load_pickle('model', 'pickled')
"""
)
e.save_source_string("model", src, is_package=True)
f2 = BytesIO()
# Option 2: save with state dict
# - more code to write to save/load the model
# + but this code can be edited later to adjust adapt the model later
with PackageExporter(f2) as e:
e.intern("**")
e.save_pickle("model", "state_dict", resnet.state_dict())
src = dedent(
"""\
import importlib
import torch_package_importer as resources
from torchvision.models.resnet import resnet18
def load():
# if you want, you can later edit how resnet is constructed here
# to edit the model in the package, while still loading the original
# state dict weights
r = resnet18()
state_dict = resources.load_pickle('model', 'state_dict')
r.load_state_dict(state_dict)
return r
"""
)
e.save_source_string("model", src, is_package=True)
# regardless of how we chose to package, we can now use the model in a server in the same way
input = torch.rand(1, 3, 224, 224)
results = []
for m in [f1, f2]:
m.seek(0)
importer = PackageImporter(m)
the_model = importer.import_module("model").load()
r = the_model(input)
results.append(r)
self.assertEqual(*results)
@skipIfNoTorchVision
def test_script_resnet(self):
resnet = resnet18()
f1 = BytesIO()
# Option 1: save by pickling the whole model
# + single-line, similar to torch.jit.save
# - more difficult to edit the code after the model is created
with PackageExporter(f1) as e:
e.intern("**")
e.save_pickle("model", "pickled", resnet)
f1.seek(0)
i = PackageImporter(f1)
loaded = i.load_pickle("model", "pickled")
# Model should script successfully.
scripted = torch.jit.script(loaded)
# Scripted model should save and load successfully.
f2 = BytesIO()
torch.jit.save(scripted, f2)
f2.seek(0)
loaded = torch.jit.load(f2)
input = torch.rand(1, 3, 224, 224)
self.assertEqual(loaded(input), resnet(input))
if __name__ == "__main__":
run_tests()