metadata parsing

[heabeounMKTO]

attempt at issue 1006

• load meta data from onnx model path.

[kali]

Hello, thanks for your interest in tract.

What are we trying to achieve here ? If we want to integrate ONNX metadata with tract, there are a couple issue I think is worth considering:

• put the ONNX metadata in tract models metadata somehow to avoid introducing a separate API and concepts
• this code assumes a file and a path, while models can be loaded from buffers as well (it is useful to load models from http endpoints in CI settings)
• mmap is not portable to wasm

I think we can kill this three birds with one stone actually, if we handle metadata parsing and rewrapping in tract metadata inside onnx model loading functions.

Alternatively, maybe what you are trying to achieve is a metadata access that does not require reading the entire file...

WDYT ?

[heabeounMKTO]

i want to be able to access onnx metadata through the onnx model, similar to how we can access it through python. so i think i'll wrap the parsing of metadata in the onnx loading function, thanks!

[heabeounMKTO]

ive put a new loading function inside of the Onnx struct , since i'm learning rust , i'm not sure if this is the correct way to do it , please kindly advise :) @kali

[kali]

OK, so this is not what I had in mind. What I was thinking was:
1/ load the ONNX metadata in parse_with_template, refactoring the operator set version extraction which is actually part of the metadata
2/ inject them in the "properties" of the template model (or after building the graph)

WDYT ?

[heabeounMKTO]

i actually thought about doing it that way too but i thought it was too complex for me to implement it , now that you mentioned it , i will take it up as a challenge and re-implement it in that way , thanks for the advice ! :)