1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291

/*
 * Copyright (c) 2011.  Peter Lawrey
 *
 * "THE BEER-WARE LICENSE" (Revision 128)
 * As long as you retain this notice you can do whatever you want with this stuff.
 * If we meet some day, and you think this stuff is worth it, you can buy me a beer in return
 * There is no warranty.
 */

package com.google.code.java.core.sizeof;

import org.junit.Test;

import java.util.ArrayList;
import java.util.BitSet;
import java.util.LinkedList;

public class MemoryUsageExamplesTest {
  @Test
  public void testStringPlus() {

    System.out.printf("The average memory used by StringBuilder for \"abc\" + \"def\" is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        StringBuilder a2f = new StringBuilder().append("abc").append("def");
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by a new \"abcdef\" String is %.1f bytes%n", new SizeofUtil() {
      char[] chars = "abcdef".toCharArray();

      @Override
      protected int create() {
        String a2f = new String(chars);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by \"abc\" + \"def\" is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        String a2c = "abc";
        String a2f = a2c + "def";
        return 1;
      }
    }.averageBytes());
  }

  @Test
  public void testArray() {
    System.out.printf("The average memory used by new BitSet(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        BitSet array = new BitSet(1024);
        for (int i = 0; i < array.length(); i++) array.set(i, i % 2 == 0);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by boolean[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        boolean[] array = new boolean[1024];
        for (int i = 0; i < array.length; i++) array[i] = i % 2 == 0;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Boolean[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Boolean[] array = new Boolean[1024];
        for (int i = 0; i < array.length; i++) array[i] = i % 2 == 0;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<Boolean>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<Boolean> array = new ArrayList<Boolean>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, i % 2 == 0);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<Boolean>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<Boolean> array = new LinkedList<Boolean>();
        for (int i = 0; i < 1024; i++) array.add(i, i % 2 == 0);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by byte[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        byte[] array = new byte[1024];
        for (int i = 0; i < array.length; i++) array[i] = (byte) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Byte[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Byte[] array = new Byte[1024];
        for (int i = 0; i < array.length; i++) array[i] = (byte) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<Byte>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<Byte> array = new ArrayList<Byte>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, (byte) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<Byte>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<Byte> array = new LinkedList<Byte>();
        for (int i = 0; i < 1024; i++) array.add(i, (byte) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by char[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        char[] array = new char[1024];
        for (int i = 0; i < array.length; i++) array[i] = (char) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Character[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Character[] array = new Character[1024];
        for (int i = 0; i < array.length; i++) array[i] = (char) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by short[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        short[] array = new short[1024];
        for (int i = 0; i < array.length; i++) array[i] = (short) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Short[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Short[] array = new Short[1024];
        for (int i = 0; i < array.length; i++) array[i] = (short) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<Short/Character>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<Short> array = new ArrayList<Short>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, (short) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<Short/Character>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<Short> array = new LinkedList<Short>();
        for (int i = 0; i < 1024; i++) array.add(i, (short) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by int[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        int[] ints = new int[1024];
        for (int i = 0; i < ints.length; i++) ints[i] = i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Integer[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Integer[] ints = new Integer[1024];
        for (int i = 0; i < ints.length; i++) ints[i] = i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<Integer/Float>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<Integer> array = new ArrayList<Integer>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, (int) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<Integer/Float>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<Integer> array = new LinkedList<Integer>();
        for (int i = 0; i < 1024; i++) array.add(i, (int) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by float[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        float[] array = new float[1024];
        for (int i = 0; i < array.length; i++) array[i] = (float) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Float[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Float[] array = new Float[1024];
        for (int i = 0; i < array.length; i++) array[i] = (float) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by long[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        long[] array = new long[1024];
        for (int i = 0; i < array.length; i++) array[i] = (long) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Long[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Long[] array = new Long[1024];
        for (int i = 0; i < array.length; i++) array[i] = (long) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<Long/Double>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<Long> array = new ArrayList<Long>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, (long) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<Long/Double>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<Long> array = new LinkedList<Long>();
        for (int i = 0; i < 1024; i++) array.add(i, (long) i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by double[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        double[] array = new double[1024];
        for (int i = 0; i < array.length; i++) array[i] = (double) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by Double[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        Double[] array = new Double[1024];
        for (int i = 0; i < array.length; i++) array[i] = (double) i;
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by String[1024] is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        String[] array = new String[1024];
        for (int i = 0; i < array.length; i++) array[i] = String.valueOf(i);
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new ArrayList<String>(1024) is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        ArrayList<String> array = new ArrayList<String>(1024);
        for (int i = 0; i < 1024; i++) array.add(i, String.valueOf(i));
        return 1;
      }
    }.averageBytes());
    System.out.printf("The average memory used by new LinkedList<String>() with 1024 elements is %.1f bytes%n", new SizeofUtil() {
      @Override
      protected int create() {
        LinkedList<String> array = new LinkedList<String>();
        for (int i = 0; i < 1024; i++) array.add(i, String.valueOf(i));
        return 1;
      }
    }.averageBytes());
  }
}