Maybe use Bytes within AlignedBuffer

[JackKelly]

See this code sketch for how to create a Bytes from an aligned buffer.

This will get easier if my PR to Bytes gets accepted: tokio-rs/bytes#684

Why?

Once the operating system has written into these buffers, I'd love to wrap the buffer in Bytes so I can:

• share read-only access to multiple "owned" slices of the buffer.
• match existing API's like object_store's API which returns Bytes.

[JackKelly]

Conclusion: Can't use Bytes (as it stands today)

Actually, as Bytes stands today, I don't think it's possible to safely wrap an aligned buffer in Bytes. The problem is that dealloc needs to know the layout, and I can't think of a way to tell Bytes.vtable.drop about the layout (it always assumes the layout is 1).

One day, Bytes might implement a new vtable API: tokio-rs/bytes#437

Until that day, I suspect the easiest solution will be to implement a minimal set of Bytes-like behaviour in my AlignedBuffer crate

[JackKelly]

I've submitted a detailed write-up of my use-case to the Bytes issue discussing the new vtable API: tokio-rs/bytes#437 (comment)