fast hash types

fasthash.cljs

(deftype IdAttr [id attr ^:mutable ^number _hasheq]
  IEquiv
  (-equiv
    [this that]
    (boolean
     (or (identical? this that)
         (and (instance? IdAttr that)
              (= id (.-id ^IdAttr that))
              (= attr (.-attr ^IdAttr that))))))

  IIndexed
  (-nth [coll n] (-nth coll n nil))
  (-nth [coll n not-found] (case n, 0 id, 1 attr, not-found))
  
  IHash
  (-hash [o] 
    (if (zero? _hasheq)
      (set! _hasheq (+ (* 31 (hash id)) (hash attr)))
      _hasheq)))

(deftype IdAttrs [last-object h]
  IStack
  (-peek [coll] last-object)
  ICollection
  (-conj [coll o]
    (IdAttrs. o (+ h (* 31 (hash o)))))
  IEquiv
  (-equiv
    [this that]
    (boolean (or (identical? this that)
                 (and (instance? IdAttrs that)
                      (= h (.-h ^IdAttrs that))
                      (= last-object (.-last-object ^IdAttrs that))))))
  IHash
  (-hash [o] h))

(comment
  
  (simple-benchmark []
                    (get {(into [(->IdAttr 1 :foo 0)]
                                [(->IdAttr 1 :foo 0)
                                 (->IdAttr 1 :foo 0)])
                          1}
                         (into [(->IdAttr 1 :foo 0)]
                               [(->IdAttr 1 :foo 0)
                                (->IdAttr 1 :foo 0)]))
                    100000)
  (simple-benchmark []
                    (get {(into
                           (IdAttrs. (->IdAttr 1 :foo 0) (* 31 (hash (->IdAttr 1 :foo 0))))
                           [(->IdAttr 1 :foo 0)
                            (->IdAttr 1 :foo 0)])
                          1}
                         (into
                          (IdAttrs. (->IdAttr 1 :foo 0) (* 31 (hash (->IdAttr 1 :foo 0))))
                          [(->IdAttr 1 :foo 0)
                           (->IdAttr 1 :foo 0)]))
                    100000)
  (simple-benchmark []
                    (= (->IdAttr 1 :foo 0)
                       (->IdAttr 1 :foo 0))
                    1000000)
  (simple-benchmark [] (= [1 :foo] [1 :foo])
                    1000000)
  )