ScriptModuleOp in caffe2 (#18716)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18716
Might be useful as an intermediate stage for some systems that currently use Caffe2 nets as an execution mechanism.
Not sure it's a good idea all together, please comment.
Limitations:
- only Tensor types as inputs/outputs
- the entire module is serialized as a zip archive inside a proto in Caffe2 db, it'd be subject to 4Gb limit and is likely very slow. For small models it'd work though.
- no autograd, though it can be attached in principle
- no way to retrieve parameters inside the script module from C2 runtime perspective (though they potentially can be alias-fetched and stored as individual blobs)
- after deserialization, python wrappers returned don't have correct type (as we don't do module_lookup trick)
Build-wise, I had to add dependency from pybind_state to libtorch.so. I don't think we build Caffe2 python frontend independently anymore, so it should be fine.
Reviewed By: amirshim, houseroad
Differential Revision: D14339599
fbshipit-source-id: 88a37a8abd1f1c4703e5ef937031f222535d4080
