Feature Description

@Xuanwo i was working the side to prepare a PR which allows opendal as an external byte source for Polars.

While doing this i came across a few limitation which need Debug to be implemented for Reader and Writer. For now I have implemented these on my end directly, but i was thinking if these can be implemented directly in core since ReadContext is private, maybe some non critical metadata can be exposed?

Problem and Solution

With this I also have the following suggestions,

• When reader is created, maybe a stat call can be triggered eagerly which exposes the Metadata object as a field in reader. The reader can fail eagerly if the object doesn't exist on this basis.
• as i remember, this eager call is anyways triggered when user passes byte range as .., so might as well do this beforehand.
• Metadata has a lot of info already but some things like scheme, prefix, and fully qualified path are still missing, but they're available in the ReaderContext.

What do you think?

Additional Context

Ref: #5972

Are you willing to contribute to the development of this feature?

• Yes, I am willing to contribute to the development of this feature.