1 /*
   2  * Copyright (c) 2015, 2018, 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     }
  46 
  47     static int bucket(int val) {
  48         for (int i = 1; i < MAX; i++) {
  49             if (val < STEPS[i]) {
  50                 return i - 1;
  51             }
  52         }
  53         return LAST;
  54     }
  55 
  56     private final StatLong[] stats = new StatLong[MAX];
  57 
  58     public Histogram(final String name) {
  59         super(name);
  60         for (int i = 0; i < MAX; i++) {
  61             stats[i] = new StatLong(String.format("%5s .. %5s", STEPS[i],
  62                                     ((i + 1 < MAX) ? STEPS[i + 1] : "~")));
  63         }
  64     }
  65 
  66     @Override
  67     public void reset() {
  68         super.reset();
  69         for (int i = 0; i < MAX; i++) {
  70             stats[i].reset();
  71         }
  72     }
  73 
  74     @Override
  75     public void add(int val) {
  76         super.add(val);
  77         stats[bucket(val)].add(val);
  78     }
  79 
  80     @Override
  81     public void add(long val) {
  82         add((int) val);
  83     }
  84 
  85     @Override
  86     public String toString() {
  87         final StringBuilder sb = new StringBuilder(2048);
  88         super.toString(sb).append(" { ");
  89 
  90         for (int i = 0; i < MAX; i++) {
  91             if (stats[i].count != 0l) {
  92                 sb.append("\n        ").append(stats[i].toString());
  93             }
  94         }
  95 
  96         return sb.append(" }").toString();
  97     }
  98 }
  99