core.clj

(ns hdr-histogram-profile.core
  (:require [taoensso.timbre :as timbre])
  (:import [org.HdrHistogram Histogram HistogramLogWriter]
           [java.nio ByteBuffer]))

(timbre/refer-timbre)

(defnp record [^Histogram h value]
  (.recordValue h value)
  h)

(defn encoded-size [^Histogram h]
  (.getNeededByteBufferCapacity h))

(defn byte-buffer-for [^Histogram h]
  (ByteBuffer/allocate (encoded-size h)))

(defnp encode [^Histogram h]
  (let [buffer (byte-buffer-for h)]
    (.encodeIntoByteBuffer h buffer)
    (.rewind buffer)))

(defnp decode [^ByteBuffer b max-value]
  (Histogram/decodeFromByteBuffer b max-value))

(defnp decode-record-encode [^ByteBuffer buffer value]
  (-> buffer
       (decode 10000)
       (record value)
       (encode)))

(defn histogram
  ([significant-digits]
   (Histogram. significant-digits))
  ([ceiling significant-digits]
   (Histogram. ceiling significant-digits))
  ([floor ceiling significant-digits]
   (Histogram. floor ceiling significant-digits)))

(comment
  (defproject hdr-histogram-profile "0.1.0-SNAPSHOT"
    :description "FIXME: write description"
    :url "http://example.com/FIXME"
    :license {:name "Eclipse Public License"
              :url "http://www.eclipse.org/legal/epl-v10.html"}
    :dependencies [[org.clojure/clojure "1.6.0"]
                   [org.hdrhistogram/HdrHistogram "2.1.4"]
                   [com.taoensso/timbre "3.4.0"]])

  (profile :info :decode-record-encode
           (let [h      (histogram 10000 3)
                 store  (atom (encode h))]
             (dotimes [n 1000000]
               (reset! store (decode-record-encode @store (rand-int 10000))))
             (info "Total count" (.getTotalCount (decode @store 10000)))))

"2015-Mar-01 09:08:21 -0700 bcotton-MBR.local INFO [hdr-histogram-profile.core] - Total count 1000000
 2015-Mar-01 09:08:21 -0700 bcotton-MBR.local INFO [hdr-histogram-profile.core] - Profiling: :hdr-histogram-profile.core/decode-record-encode
                                              Id      nCalls       Min        Max       MAD      Mean   Time% Time
:hdr-histogram-profile.core/decode-record-encode   1,000,000    21.0μs     96.0ms     8.0μs    63.0μs      97 63.1s
              :hdr-histogram-profile.core/decode   1,000,001       0ns      6.0ms     3.0μs    35.0μs      54 34.7s
              :hdr-histogram-profile.core/encode   1,000,001       0ns      8.0ms     2.0μs    23.0μs      36 23.5s
                                :timbre/stats-gc          36    36.0ms     57.0ms     5.0ms    48.0ms       3 1.7s
              :hdr-histogram-profile.core/record   1,000,000       0ns     39.0μs      95ns      50ns       0 51.0ms
                                      Clock Time                                                          100 64.8s
                                  Accounted Time                                                          190 123.1s"

)