pseudo code for back pressure bridging

bp.clj

(a/go-loop [async-tcp-connections-to-chans ; "foreign" -> ch
            buffered ; ch -> data
            pressurized] ; ch -> foreign
  (let [cnx (select (keys async-tcp-connections-to-chans))
        ch (async-tcp-connections-to-chans cnx)
        data (read-data cnx)
        async-tcp-connections-to-chans (dissoc async-tcp-connections-to-chans cnx)
        buffered (assoc buffered ch data)
        pressurized (assoc pressurized ch cnx)]
    
    (let [[_ c] (a/alts! (vec buffered)
                  :default :bp)]
      (if (= :default c)
        (recur async-tcp-connections-to-chans buffered pressurized)
        (let [cnx (pressurized c)]
          (recur (assoc async-tcp-connections-to-chans cnx c)
            (dissoc buffered c)
            (dissoc pressurized c)))))))