idea: Add file version support for OpenDAL

[Xuanwo]

Some storage services, such as Amazon S3, have built-in support for versioning.

This is achieved through a feature called ObjectVersion, which allows the same object to exist in multiple versions and be accessed separately even after deletion. With this feature, users can ensure the safety of their data by rolling back to previous versions in case of unintended deletions or changes.

It would be natural to implement it, like:

• include a version argument in the OpRead, OpStat, and OpDelete.
• Add version in Metadata

We need to consider various services. Currently, I plan to investigate the object version features of the following services to ensure our design is appropriate:

• AWS S3 Object Version
• Azblob Blob Versioning
• GCS Object Versioning

[drmingdrmer]

Oh I need this feature to update an s3 object in a CAS manner!

Or, is there any other approach than using version id to ensure that the object remains unchanged during the update?

[Xuanwo]

Oh I need this feature to update an s3 object in a CAS manner!

Yes, we can read object with version_id like:

let content = op.read_with("path/to/file", OpRead::new().with_version("<version_id>")).await?;

Or, is there any other approach than using version id to ensure that the object remains unchanged during the update?

I have no idea for this now

[Xuanwo]

Thanks @suyanhanx for implementing the RFC!