01: /*
02: Copyright (c) 2003-2005, Dennis M. Sosnoski
03: All rights reserved.
04:
05: Redistribution and use in source and binary forms, with or without modification,
06: are permitted provided that the following conditions are met:
07:
08: * Redistributions of source code must retain the above copyright notice, this
09: list of conditions and the following disclaimer.
10: * Redistributions in binary form must reproduce the above copyright notice,
11: this list of conditions and the following disclaimer in the documentation
12: and/or other materials provided with the distribution.
13: * Neither the name of JiBX nor the names of its contributors may be used
14: to endorse or promote products derived from this software without specific
15: prior written permission.
16:
17: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
18: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19: WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20: DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
21: ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22: (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23: LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
24: ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25: (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26: SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27: */
28:
29: package org.jibx.binding.util;
30:
31: /**
32: * Cache of <code>Integer</code> values. This is designed on the assumption that
33: * clients will start with zero and work their way up from there. By holding
34: * created instances in an array it allows for full reuse.
35: *
36: * @author Dennis M. Sosnoski
37: * @version 1.0
38: */
39:
40: public abstract class IntegerCache {
41: /** Initial set of index values supported. */
42: private static Integer[] s_integers = { new Integer(0),
43: new Integer(1), new Integer(2), new Integer(3),
44: new Integer(4), new Integer(5), new Integer(6),
45: new Integer(7) };
46:
47: /**
48: * Get <code>Integer</code> for value.
49: *
50: * @param value non-negative integer value
51: * @return corresponding <code>Integer</code> value
52: */
53:
54: public static Integer getInteger(int value) {
55: if (value >= s_integers.length) {
56:
57: // Note that in multithreaded operation there's a chance of two
58: // threads getting in a race condition here, but the worst that
59: // can happen is that the array gets extended more than it needs
60: // to be. Threads just using the array are safe - though if they
61: // get an old version they may again extend the array
62: // unnecessarily.
63: synchronized (IntegerCache.class) {
64: int size = s_integers.length * 3 / 2;
65: if (size <= value) {
66: size = value + 1;
67: }
68: Integer[] ints = new Integer[size];
69: System.arraycopy(s_integers, 0, ints, 0,
70: s_integers.length);
71: for (int i = 0; i < size; i++) {
72: ints[i] = new Integer(i);
73: }
74: s_integers = ints;
75: }
76: }
77: return s_integers[value];
78: }
79: }
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