1 /*
2 * Copyright (c) 2003 The Visigoth Software Society. All rights
3 * reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. The end-user documentation included with the redistribution, if
18 * any, must include the following acknowledgement:
19 * "This product includes software developed by the
20 * Visigoth Software Society (http://www.visigoths.org/)."
21 * Alternately, this acknowledgement may appear in the software itself,
22 * if and wherever such third-party acknowledgements normally appear.
23 *
24 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
25 * project contributors may be used to endorse or promote products derived
26 * from this software without prior written permission. For written
27 * permission, please contact visigoths@visigoths.org.
28 *
29 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
30 * nor may "FreeMarker" or "Visigoth" appear in their names
31 * without prior written permission of the Visigoth Software Society.
32 *
33 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36 * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
37 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of the Visigoth Software Society. For more
49 * information on the Visigoth Software Society, please see
50 * http://www.visigoths.org/
51 */
52
53 package freemarker.template.utility;
54
55 import java.math.BigDecimal;
56 import java.math.BigInteger;
57 import java.util.ArrayList;
58 import java.util.Collections;
59 import java.util.List;
60
61 /**
62 * @version $Id: OptimizerUtil.java,v 1.9 2003/02/25 11:52:58 szegedia Exp $
63 * @author Attila Szegedi
64 */
65 public class OptimizerUtil
66 {
67 private static final BigInteger INTEGER_MIN = new BigInteger(Integer.toString(Integer.MIN_VALUE));
68 private static final BigInteger INTEGER_MAX = new BigInteger(Integer.toString(Integer.MAX_VALUE));
69 private static final BigInteger LONG_MIN = new BigInteger(Long.toString(Long.MIN_VALUE));
70 private static final BigInteger LONG_MAX = new BigInteger(Long.toString(Long.MAX_VALUE));
71
72 private OptimizerUtil()
73 {
74 }
75
76 public static List optimizeListStorage(List list)
77 {
78 switch(list.size())
79 {
80 case 0:
81 {
82 return Collections.EMPTY_LIST;
83 }
84 case 1:
85 {
86 return Collections12.singletonList(list.get(0));
87 }
88 default:
89 {
90 if(list instanceof ArrayList)
91 {
92 ((ArrayList)list).trimToSize();
93 }
94 return list;
95 }
96 }
97 }
98
99 /**
100 * This is needed to reverse the extreme conversions in arithmetic
101 * operations so that numbers can be meaningfully used with models that
102 * don't know what to do with a BigDecimal. Of course, this will make
103 * impossible for these models (i.e. Jython) to receive a BigDecimal even if
104 * it was originally placed as such in the data model. However, since
105 * arithmetic operations aggressively erase the information regarding the
106 * original number type, we have no other choice to ensure expected operation
107 * in majority of cases.
108 */
109 public static Number optimizeNumberRepresentation(Number number)
110 {
111 if(number instanceof BigDecimal)
112 {
113 BigDecimal bd = (BigDecimal) number;
114 if(bd.scale() == 0)
115 {
116 // BigDecimal -> BigInteger
117 number = bd.unscaledValue();
118 }
119 else
120 {
121 double d = bd.doubleValue();
122 if(d != Double.POSITIVE_INFINITY && d != Double.NEGATIVE_INFINITY)
123 {
124 // BigDecimal -> Double
125 return new Double(d);
126 }
127 }
128 }
129 if(number instanceof BigInteger)
130 {
131 BigInteger bi = (BigInteger)number;
132 if(bi.compareTo(INTEGER_MAX) <= 0 && bi.compareTo(INTEGER_MIN) >= 0)
133 {
134 // BigInteger -> Integer
135 return new Integer(bi.intValue());
136 }
137 if(bi.compareTo(LONG_MAX) <= 0 && bi.compareTo(LONG_MIN) >= 0)
138 {
139 // BigInteger -> Long
140 return new Long(bi.longValue());
141 }
142 }
143 return number;
144 }
145 }