1 /*
   2  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.marlin.stats;
  27 
  28 /**
  29  * Generic histogram based on long statistics
  30  */
  31 public final class Histogram extends StatLong {
  32 
  33     static final int BUCKET = 2;
  34     static final int MAX = 20;
  35     static final int LAST = MAX - 1;
  36     static final int[] STEPS = new int[MAX];
  37 
  38     static {
  39             STEPS[0] = 0;
  40             STEPS[1] = 1;
  41 
  42             for (int i = 2; i < MAX; i++) {
  43                 STEPS[i] = STEPS[i - 1] * BUCKET;
  44             }
  45 //            System.out.println("Histogram.STEPS = " + Arrays.toString(STEPS));
  46     }
  47 
  48     static int bucket(int val) {
  49         for (int i = 1; i < MAX; i++) {
  50             if (val < STEPS[i]) {
  51                 return i - 1;
  52             }
  53         }
  54         return LAST;
  55     }
  56 
  57     private final StatLong[] stats = new StatLong[MAX];
  58 
  59     public Histogram(final String name) {
  60         super(name);
  61         for (int i = 0; i < MAX; i++) {
  62             stats[i] = new StatLong(String.format("%5s .. %5s", STEPS[i],
  63                                     ((i + 1 < MAX) ? STEPS[i + 1] : "~")));
  64         }
  65     }
  66 
  67     @Override
  68     public void reset() {
  69         super.reset();
  70         for (int i = 0; i < MAX; i++) {
  71             stats[i].reset();
  72         }
  73     }
  74 
  75     @Override
  76     public void add(int val) {
  77         super.add(val);
  78         stats[bucket(val)].add(val);
  79     }
  80 
  81     @Override
  82     public void add(long val) {
  83         add((int) val);
  84     }
  85 
  86     @Override
  87     public String toString() {
  88         final StringBuilder sb = new StringBuilder(2048);
  89         super.toString(sb).append(" { ");
  90 
  91         for (int i = 0; i < MAX; i++) {
  92             if (stats[i].count != 0l) {
  93                 sb.append("\n        ").append(stats[i].toString());
  94             }
  95         }
  96 
  97         return sb.append(" }").toString();
  98     }
  99 }
 100