torch.package - a way to package models and code (#45015)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45015
torch.package allows you to write packages of code, pickled python data, and
arbitrary binary and text resources into a self-contained package.
torch.package.PackageExporter writes the packages and
torch.package.PackageImporter reads them.
The importers can load this code in a hermetic way, such that code is loaded
from the package rather than the normal python import system. This allows
for the packaging of PyTorch model code and data so that it can be run
on a server or used in the future for transfer learning.
The code contained in packages is copied file-by-file from the original
source when it is created, and the file format is a specially organized
zip file. Future users of the package can unzip the package, and edit the code
in order to perform custom modifications to it.
The importer for packages ensures that code in the module can only be loaded from
within the package, except for modules explicitly listed as external using :method:`extern_module`.
The file `extern_modules` in the zip archive lists all the modules that a package externally depends on.
This prevents "implicit" dependencies where the package runs locally because it is importing
a locally-installed package, but then fails when the package is copied to another machine.
Test Plan: Imported from OSS
Reviewed By: SplitInfinity
Differential Revision: D23824337
Pulled By: zdevito
fbshipit-source-id: 1247c34ba9b656f9db68a83e31f2a0fbe3bea6bd
