Rack Middleware to automatically unzip gzipped/deflated POST data

compress_requests.rb

class CompressedRequests
  def initialize(app)
    @app = app
  end
  
  def call(env)
    if env['REQUEST_METHOD'] =~ /(POST|PUT)/ 
      if env.keys.include? 'HTTP_CONTENT_ENCODING'
        
        input = env['rack.input'].read
        new_input = decode(input, env['HTTP_CONTENT_ENCODING'])
      
        env['rack.input'] = StringIO.new(new_input)
        env['CONTENT_LENGTH'] = new_input.length

        env.delete('HTTP_CONTENT_ENCODING')
      end
    end

    status, headers, response = @app.call(env)
    return [status, headers, response]
  end
  
  def decode(input, content_encoding)
    if content_encoding == 'gzip'
      z = Zlib::GzipReader.new(StringIO.new(input)).read
    elsif content_encoding == 'deflate'
      Zlib::Inflate.new.inflate new input
    else
      input
    end
  end
end

Out of curiosity, how do you instantiate CompressedRequests into the Rack? I'm trying to do the same, but my ['rack.input'] won't write.

I suspect that the correct version, dealing better with utf-8 (chars vs bytes) :

   env['CONTENT_LENGTH'] = new_input.bytes.size