core: Implement concurrent read for blocking read

[Xuanwo]

We can generate different ranges and then use rayon to concurrently fetch them.

[hoslo]

Does this require an RFC or can it be done directly?

[Xuanwo]

Does this require an RFC or can it be done directly?

We can do it directly but I want to know about your design first.

[hoslo]

There are two scenarios:

1. We have an Range, split it into concurrent intervals and read it using rayon
2. No Range, read in parallel with concurrent using 1024 * 1024 * 4 until we reach the end

[Xuanwo]

Do you have more details? What's the API will look like? How do we share the concurrent features between BlockingReader, StdReader and StdIterator?

[hoslo]

We add a field OpReader into BlockingReader and use it concurrent read in method read_at and read_into.

[Xuanwo]

We add a field OpReader into BlockingReader and use it concurrent read in method read_at and read_into.

I'm not sure if we are aligned. Please feel free to give it a try.

[Xuanwo]

Closing as no user really want this.