angerman

(in-ns 'clojure.contrib.duck-streams)
(import '(java.io File RandomAccessFile))

;; copied and adapted from c.c.ds

(defmulti #^{:arglist '([x])} random-access-reader class)
(defmethod random-access-reader File [#^File x]
  (RandomAccessFile. x "r"))
(defmethod random-access-reader String [#^String x]
  (random-access-reader (file-str x)))

angerman

 "upps.data.model")) line (.readLine raf)] nil)
; Evaluation aborted.
user> (let [raf (random-access-reader (model-file "upps.data.model"))] raf)
#<RandomAccessFile java.io.RandomAccessFile@415b15ab>
user> (let [raf (random-access-reader (model-file "upps.data.model")) line (.readLine raf)] nil)
; Evaluation aborted.
user> 

angerman

user> (compute-metrics [{} *body*])
"Elapsed time: 0.13 msecs"
"Elapsed time: 0.093 msecs"


 
user> (set! *warn-on-reflection* true) 
true
user> (def *body* (take 10 (drop-header (model-file "upps.data.model"))))
#'user/*body*

angerman

(use 'clojure.contrib.duck-streams)
(in-ns 'clojure.contrib.duck-streams)
(import '(java.io File RandomAccessFile))
(import 'BufferedRandomAccessFile)

;; copied and adapted from c.c.ds

(defmulti #^{:arglist '([x])} random-access-reader class)
(defmethod random-access-reader File [#^File x]
  (BufferedRandomAccessFile. x "r"))

angerman

/** A subclass of RandomAccessFile to enable basic buffering to a byte array
*    Copyright (C) 2009 minddumped.blogspot.com

*  This program is free software: you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation, either version 3 of the License, or
*  (at your option) any later version.

*  This program is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of

angerman

(with-random-access-reader "/Users/angerman/upps.data.model"
  (println (next-line)) ;; first line
  (println (next-line)) ;; second line
  (save-excursion
   (println (subs (last (lazy-rest)) 0 20))) ;; last line's first 20 char
  (println (next-line)) ;; third line
  (println (subs (last (lazy-rest)) 0 20))) ;; last lines first 20 char

angerman

(defmacro timer
  [expr]
  `(let [start# (. System (nanoTime))
         ret# ~expr]
     (/ (double (- (. System (nanoTime)) start#)) 1000000.0)))

(defmacro statistics [n expr]
  `(let [timings# (take ~n (repeatedly (fn [] (timer ~expr))))
         min# (apply min timings#)
         max# (apply max timings#)

angerman

(use 'clojure.contrib.duck-streams)
(in-ns 'clojure.contrib.duck-streams)
(import '(java.io File RandomAccessFile))
(import 'BufferedRandomAccessFile)

;; copied and adapted from c.c.ds

(defmulti #^{:arglist '([x])} random-access-reader class)
(defmethod random-access-reader File [#^File x]
  (BufferedRandomAccessFile. x "r"))

angerman

/** A subclass of RandomAccessFile to enable basic buffering to a byte array
*    Copyright (C) 2009 minddumped.blogspot.com

*  This program is free software: you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation, either version 3 of the License, or
*  (at your option) any later version.

*  This program is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of

angerman

user> (statistics 25 (with-open [rar (random-access-reader (model-file "upps.data.model"))] (doseq [line (lazy-rest rar)] nil)))
Runs: 25
Min:      1740.527
Max:      2911.521
Mean:     2516.340
Median:   2326.024
sd:        424.961