Source Code Cross Referenced for IntToIntHashMap.java in  » XML » saxonb » net » sf » saxon » sort » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Java Source Code / Java Documentation
1. 6.0 JDK Core
2. 6.0 JDK Modules
3. 6.0 JDK Modules com.sun
4. 6.0 JDK Modules com.sun.java
5. 6.0 JDK Modules sun
6. 6.0 JDK Platform
7. Ajax
8. Apache Harmony Java SE
9. Aspect oriented
10. Authentication Authorization
11. Blogger System
12. Build
13. Byte Code
14. Cache
15. Chart
16. Chat
17. Code Analyzer
18. Collaboration
19. Content Management System
20. Database Client
21. Database DBMS
22. Database JDBC Connection Pool
23. Database ORM
24. Development
25. EJB Server geronimo
26. EJB Server GlassFish
27. EJB Server JBoss 4.2.1
28. EJB Server resin 3.1.5
29. ERP CRM Financial
30. ESB
31. Forum
32. GIS
33. Graphic Library
34. Groupware
35. HTML Parser
36. IDE
37. IDE Eclipse
38. IDE Netbeans
39. Installer
40. Internationalization Localization
41. Inversion of Control
42. Issue Tracking
43. J2EE
44. JBoss
45. JMS
46. JMX
47. Library
48. Mail Clients
49. Net
50. Parser
51. PDF
52. Portal
53. Profiler
54. Project Management
55. Report
56. RSS RDF
57. Rule Engine
58. Science
59. Scripting
60. Search Engine
61. Security
62. Sevlet Container
63. Source Control
64. Swing Library
65. Template Engine
66. Test Coverage
67. Testing
68. UML
69. Web Crawler
70. Web Framework
71. Web Mail
72. Web Server
73. Web Services
74. Web Services apache cxf 2.0.1
75. Web Services AXIS2
76. Wiki Engine
77. Workflow Engines
78. XML
79. XML UI
Java
Java Tutorial
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Source Code / Java Documentation » XML » saxonb » net.sf.saxon.sort 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        package net.sf.saxon.sort;
002:
003:        import java.io.Serializable;
004:
005:        /**
006:         * A hash table that maps int keys to int values.
007:         *
008:         * @author Dave Hale, Landmark Graphics
009:         * @author Dominique Devienne
010:         * @author Michael Kay: created this class based on IntHashMap
011:         */
012:        public class IntToIntHashMap implements  Serializable {
013:
014:            /**
015:             * Initializes a map with a capacity of 8 and a load factor of 0,25.
016:             */
017:            public IntToIntHashMap() {
018:                this (8, 0.25);
019:            }
020:
021:            /**
022:             * Initializes a map with the given capacity and a load factor of 0,25.
023:             *
024:             * @param capacity the initial capacity.
025:             */
026:            public IntToIntHashMap(int capacity) {
027:                this (capacity, 0.25);
028:            }
029:
030:            /**
031:             * Constructs a new map with initial capacity, and load factor.
032:             * <p/>
033:             * The capacity is the number of keys that can be mapped without resizing
034:             * the arrays in which keys and values are stored. For efficiency, only
035:             * a fraction of the elements in those arrays are used. That fraction is
036:             * the specified load factor. The initial length of the arrays equals the
037:             * smallest power of two not less than the ratio capacity/factor. The
038:             * capacity of the map is increased, as necessary. The maximum number
039:             * of keys that can be mapped is 2^30.
040:             *
041:             * @param capacity the initial capacity.
042:             * @param factor   the load factor.
043:             */
044:            public IntToIntHashMap(int capacity, double factor) {
045:                _factor = factor;
046:                setCapacity(capacity);
047:            }
048:
049:            /**
050:             * Set the value to be returned to indicate an unused entry
051:             */
052:            public void setDefaultValue(int defaultValue) {
053:                _defaultValue = defaultValue;
054:            }
055:
056:            /**
057:             * Clears the map.
058:             */
059:            public void clear() {
060:                _n = 0;
061:                for (int i = 0; i < _nmax; ++i) {
062:                    _filled[i] = false;
063:                }
064:            }
065:
066:            /**
067:             * Finds a key in the map.
068:             *
069:             * @param key Key
070:             * @return true if the key is mapped
071:             */
072:            public boolean find(int key) {
073:                return _filled[indexOf(key)] ? true : false;
074:            }
075:
076:            /**
077:             * Gets the value for this key.
078:             *
079:             * @param key Key
080:             * @return the value, null if not found.
081:             */
082:            public int get(int key) {
083:                int i = indexOf(key);
084:                return _filled[i] ? _value[i] : _defaultValue;
085:            }
086:
087:            /**
088:             * Gets the size of the map.
089:             *
090:             * @return the size
091:             */
092:            public int size() {
093:                return _n;
094:            }
095:
096:            /**
097:             * Removes a key from the map.
098:             *
099:             * @param key Key to remove
100:             * @return true if the value was removed
101:             */
102:            public boolean remove(int key) {
103:                // Knuth, v. 3, 527, Algorithm R.
104:                int i = indexOf(key);
105:                if (!_filled[i]) {
106:                    return false;
107:                }
108:                --_n;
109:                for (;;) {
110:                    _filled[i] = false;
111:                    int j = i;
112:                    int r;
113:                    do {
114:                        i = (i - 1) & _mask;
115:                        if (!_filled[i]) {
116:                            return true;
117:                        }
118:                        r = hash(_key[i]);
119:                    } while ((i <= r && r < j) || (r < j && j < i)
120:                            || (j < i && i <= r));
121:                    _key[j] = _key[i];
122:                    _value[j] = _value[i];
123:                    _filled[j] = _filled[i];
124:                }
125:            }
126:
127:            /**
128:             * Adds a key-value pair to the map.
129:             *
130:             * @param key   Key
131:             * @param value Value
132:             */
133:            public void put(int key, int value) {
134:                int i = indexOf(key);
135:                if (_filled[i]) {
136:                    _value[i] = value;
137:                } else {
138:                    _key[i] = key;
139:                    _value[i] = value;
140:                    _filled[i] = true;
141:                    grow();
142:                }
143:            }
144:
145:            ///////////////////////////////////////////////////////////////////////////
146:            // private
147:
148:            private static final int NBIT = 30; // NMAX = 2^NBIT
149:            private static final int NMAX = 1 << NBIT; // maximum number of keys mapped
150:            private double _factor; // 0.0 <= _factor <= 1.0
151:            private int _defaultValue = Integer.MAX_VALUE;
152:            private int _nmax; // 0 <= _nmax = 2^nbit <= 2^NBIT = NMAX
153:            private int _n; // 0 <= _n <= _nmax <= NMAX
154:            private int _nlo; // _nmax*_factor (_n<=_nlo, if possible)
155:            private int _nhi; //  NMAX*_factor (_n< _nhi, if possible)
156:            private int _shift; // _shift = 1 + NBIT - nbit (see function hash() below)
157:            private int _mask; // _mask = _nmax - 1
158:            private int[] _key; // array[_nmax] of keys
159:            //@SuppressWarnings(value = {"unchecked"})
160:            private int[] _value; // array[_nmax] of values
161:            private boolean[] _filled; // _filled[i]==true iff _key[i] is mapped
162:
163:            private int hash(int key) {
164:                // Knuth, v. 3, 509-510. Randomize the 31 low-order bits of c*key
165:                // and return the highest nbits (where nbits <= 30) bits of these.
166:                // The constant c = 1327217885 approximates 2^31 * (sqrt(5)-1)/2.
167:                return ((1327217885 * key) >> _shift) & _mask;
168:            }
169:
170:            private int indexOf(int key) {
171:                int i = hash(key);
172:                while (_filled[i]) {
173:                    if (_key[i] == key) {
174:                        return i;
175:                    }
176:                    i = (i - 1) & _mask;
177:                }
178:                return i;
179:            }
180:
181:            private void grow() {
182:                ++_n;
183:                if (_n > NMAX) {
184:                    throw new RuntimeException("number of keys mapped exceeds "
185:                            + NMAX);
186:                }
187:                if (_nlo < _n && _n <= _nhi) {
188:                    setCapacity(_n);
189:                }
190:            }
191:
192:            private void setCapacity(int capacity) {
193:                if (capacity < _n) {
194:                    capacity = _n;
195:                }
196:                double factor = (_factor < 0.01) ? 0.01
197:                        : (_factor > 0.99) ? 0.99 : _factor;
198:                int nbit, nmax;
199:                for (nbit = 1, nmax = 2; nmax * factor < capacity
200:                        && nmax < NMAX; ++nbit, nmax *= 2) {
201:                    ;
202:                }
203:                int nold = _nmax;
204:                if (nmax == nold) {
205:                    return;
206:                }
207:                _nmax = nmax;
208:                _nlo = (int) (nmax * factor);
209:                _nhi = (int) (NMAX * factor);
210:                _shift = 1 + NBIT - nbit;
211:                _mask = nmax - 1;
212:                int[] key = _key;
213:                int[] value = _value;
214:                boolean[] filled = _filled;
215:                _n = 0;
216:                _key = new int[nmax];
217:                // semantically equivalent to _value = new V[nmax]
218:                _value = new int[nmax];
219:                _filled = new boolean[nmax];
220:                if (key != null) {
221:                    for (int i = 0; i < nold; ++i) {
222:                        if (filled[i]) {
223:                            put(key[i], value[i]);
224:                        }
225:                    }
226:                }
227:            }
228:
229:        }
230:
231:        //
232:        // The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
233:        // you may not use this file except in compliance with the License. You may obtain a copy of the
234:        // License at http://www.mozilla.org/MPL/
235:        //
236:        // Software distributed under the License is distributed on an "AS IS" basis,
237:        // WITHOUT WARRANTY OF ANY KIND, either express or implied.
238:        // See the License for the specific language governing rights and limitations under the License.
239:        //
240:        // The Original Code is: all this file.
241:        //
242:        // The Initial Developer of the Original Code is Dave Hale and Dominique Devienne of Landmark Graphics;
243:        // the code was retrofitted to JDK 1.4 by Michael Kay, Saxonica.
244:        //
245:        // Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
246:        //
247:        // Contributor(s): none.
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.