write_all about tokio-uring

[Noah-Kennedy]

Currently working on a POC for this.

[Noah-Kennedy]

@FrankReh I agree completely on a Write trait, as well as a Read trait. I think these should be called OwnedWrite and OwnedRead.

[FrankReh]

Okay. I'll keep my write_all to myself for now, but it means my other work I wanted to commit as PRs is blocked because the test case(s) use the write_all. Your Owned{Write, Read} aren't blocked by my work so I'll wait for those traits to land.

BTW my write_all is a trivial modification to the write_all in std so you may be providing it yourself in OwnedWrite. No prob. In fact, I had to decide between basing the loop on the IoBuf or Slice type and I choose Slice for no real good reason. I was going to ask your opinion anyway.

[Noah-Kennedy]

No, go ahead and open up a PR. I'm doing some refactoring right now in my PR and I don't want to block anyone with this.

[FrankReh]

@Noah-Kennedy Just a reminder that ProvideBuffers will be very nice to support with this library. I don't know how that factors into your OwnedWrite and OwnedRead trait plans. Maybe they are orthogonal. Once I get the builder api for you to look at and perhaps approved, I'll see about a builder method that lets the caller either provide buffers or call out the library to allocate its own buffers. Of course ownership of the original buffer might make it hard for me to figure out how to provide both options so I may start with the library allocating the buffers, given parameters to a builder method.

The existing io-uring library supports buffers for reading and writing to files. Interesting as a first step, but using buffers to do multi recv and recvmsg is what's really interesting to me and that comes with the next kernel, 6.0, due in Oct, next month.

Maybe this deserves its own issue. Ownership and the drop method for these fixed buffers will be interesting.

[Noah-Kennedy]

@FrankReh I think that we may need to add some additional buffer traits that abstract over things uring ops can use as buffers for use within op builders internally.

[FrankReh]

@Noah-Kennedy I'm all ears. I've created #112 to discuss fixed buffers with a pbuf_ring feature introduced in 5.19. Maybe related to internal traits, maybe not.

[Noah-Kennedy]

Thanks!