Support for zstd in Deflater about rack HOT 5 OPEN

We should define a standard interface for compression algorithms.

I don't think rack should depend on another gem, but I have no problem exposing some standard mechanism that makes it extremely easy to pull in a zstd implementation and use it everywhere that makes sense.

I agree, this makes a lot of sense for several reasons!

Could be coupled with Rack docs pointing out a few third-party gems, or just examples of how to implement it.

from rack.

To support this and potentially other compression algorithms, I think we should provide a Deflater option for custom deflaters:

use Rack::Deflater, deflaters: {"zstd"=>lambda{|headers, body| ...}}

The callable would return the deflated body. The default would be something like:

{
  "gzip"=>lambda do |headers, body|
     mtime = headers["last-modified"]
     mtime = Time.httpdate(mtime).to_i if mtime
     GzipStream.new(body, mtime, @sync)
  },
  "identity"=>lambda{|headers, body| body}
}

Not saying the implementation would use that (should probably keep the current behavior hardcoded for performance), but that would be the behavior.

from rack.

Is there a standard library for providing this? I'd be okay with accepting a PR to implement this.

from rack.

@ioquatix This is the one I know about:

https://github.com/SpringMT/zstd-ruby

from rack.

I think the way I see this playing out:

1. We should define a standard interface for compression algorithms.
2. Define some way to specify the zstd as an option in Rack, e.g. require 'rack/deflater/zstd' or something.

I don't think rack should depend on another gem, but I have no problem exposing some standard mechanism that makes it extremely easy to pull in a zstd implementation and use it everywhere that makes sense.

from rack.