|
1
11 package org.eclipse.jdt.internal.compiler.util;
12
13 import org.eclipse.jdt.core.compiler.CharOperation;
14
15
18 public final class HashtableOfObject implements Cloneable  {
19
20 public char[] keyTable[];
22 public Object valueTable[];
23
24 public int elementSize; int threshold;
26
27 public HashtableOfObject() {
28 this(13);
29 }
30
31 public HashtableOfObject(int size) {
32
33 this.elementSize = 0;
34 this.threshold = size; int extraRoom = (int) (size * 1.75f);
36 if (this.threshold == extraRoom)
37 extraRoom++;
38 this.keyTable = new char[extraRoom][];
39 this.valueTable = new Object [extraRoom];
40 }
41
42 public void clear() {
43 for (int i = this.keyTable.length; --i >= 0;) {
44 this.keyTable[i] = null;
45 this.valueTable[i] = null;
46 }
47 this.elementSize = 0;
48 }
49
50 public Object clone() throws CloneNotSupportedException {
51 HashtableOfObject result = (HashtableOfObject) super.clone();
52 result.elementSize = this.elementSize;
53 result.threshold = this.threshold;
54
55 int length = this.keyTable.length;
56 result.keyTable = new char[length][];
57 System.arraycopy(this.keyTable, 0, result.keyTable, 0, length);
58
59 length = this.valueTable.length;
60 result.valueTable = new Object [length];
61 System.arraycopy(this.valueTable, 0, result.valueTable, 0, length);
62 return result;
63 }
64
65 public boolean containsKey(char[] key) {
66 int length = keyTable.length,
67 index = CharOperation.hashCode(key) % length;
68 int keyLength = key.length;
69 char[] currentKey;
70 while ((currentKey = keyTable[index]) != null) {
71 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
72 return true;
73 if (++index == length) {
74 index = 0;
75 }
76 }
77 return false;
78 }
79
80 public Object get(char[] key) {
81 int length = keyTable.length,
82 index = CharOperation.hashCode(key) % length;
83 int keyLength = key.length;
84 char[] currentKey;
85 while ((currentKey = keyTable[index]) != null) {
86 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
87 return valueTable[index];
88 if (++index == length) {
89 index = 0;
90 }
91 }
92 return null;
93 }
94
95 public Object put(char[] key, Object value) {
96 int length = keyTable.length,
97 index = CharOperation.hashCode(key) % length;
98 int keyLength = key.length;
99 char[] currentKey;
100 while ((currentKey = keyTable[index]) != null) {
101 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
102 return valueTable[index] = value;
103 if (++index == length) {
104 index = 0;
105 }
106 }
107 keyTable[index] = key;
108 valueTable[index] = value;
109
110 if (++elementSize > threshold)
112 rehash();
113 return value;
114 }
115
116 public Object removeKey(char[] key) {
117 int length = keyTable.length,
118 index = CharOperation.hashCode(key) % length;
119 int keyLength = key.length;
120 char[] currentKey;
121 while ((currentKey = keyTable[index]) != null) {
122 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key)) {
123 Object value = valueTable[index];
124 elementSize--;
125 keyTable[index] = null;
126 valueTable[index] = null;
127 rehash();
128 return value;
129 }
130 if (++index == length) {
131 index = 0;
132 }
133 }
134 return null;
135 }
136
137 private void rehash() {
138
139 HashtableOfObject newHashtable = new HashtableOfObject(elementSize * 2); char[] currentKey;
141 for (int i = keyTable.length; --i >= 0;)
142 if ((currentKey = keyTable[i]) != null)
143 newHashtable.put(currentKey, valueTable[i]);
144
145 this.keyTable = newHashtable.keyTable;
146 this.valueTable = newHashtable.valueTable;
147 this.threshold = newHashtable.threshold;
148 }
149
150 public int size() {
151 return elementSize;
152 }
153
154 public String toString() {
155 String s = ""; Object object;
157 for (int i = 0, length = valueTable.length; i < length; i++)
158 if ((object = valueTable[i]) != null)
159 s += new String (keyTable[i]) + " -> " + object.toString() + "\n"; return s;
161 }
162 }
163 |
Popular Tags |
Java API By Example, From Geeks To Geeks.