remove actix-threadpool.use actix_rt::task::spawn_blocking

[fakeshadow]

PR Type

Dependency

PR Checklist

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• Documentation comments have been added / updated.
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Overview

Remove actix-threadpool from actix-http and actix-web.

Use actix_rt::task::spawn_blocking as the new blocking thread pool.

actix_threadpool::BlockingError has been moved into actix_http::error module and can also be import from actix_web::error module.

This is not a break change from actix-web and actix-http as the public API and types related stays the same. It's only when factoring people may use actix-threadpool together in their app and import types(BlockingError for example) from there and that would be breaking.

[robjtede]

derive_more Error would delcare E the source

[fakeshadow]

This is copied from the actix-threadpool code and I believe it's explictly added by a PR.

[robjtede]

okay can do it later if needed

[fakeshadow]

I've migrate actix-files to use spawn_blocking making it runs on typed future with every chunk. It's a semver-norelease change on it