1 /*******************************************************************************
2 * Copyright (c) 2000, 2009 IBM Corporation and others.
3 *
4 * This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License 2.0
6 * which accompanies this distribution, and is available at
7 * https://www.eclipse.org/legal/epl-2.0/
8 *
9 * SPDX-License-Identifier: EPL-2.0
10 *
11 * Contributors:
12 * IBM Corporation - initial API and implementation
13 *******************************************************************************/
14 package org.eclipse.jdt.internal.compiler.util;
15
16 import org.eclipse.jdt.core.compiler.CharOperation;
17 import org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding;
18
19 public final class HashtableOfType {
20 // to avoid using Enumerations, walk the individual tables skipping nulls
21 public char[] keyTable[];
22 public ReferenceBinding valueTable[];
23
24 public int elementSize; // number of elements in the table
25 int threshold;
HashtableOfType()26 public HashtableOfType() {
27 this(3);
28 }
HashtableOfType(int size)29 public HashtableOfType(int size) {
30 this.elementSize = 0;
31 this.threshold = size; // size represents the expected number of elements
32 int extraRoom = (int) (size * 1.75f);
33 if (this.threshold == extraRoom)
34 extraRoom++;
35 this.keyTable = new char[extraRoom][];
36 this.valueTable = new ReferenceBinding[extraRoom];
37 }
containsKey(char[] key)38 public boolean containsKey(char[] key) {
39 int length = this.keyTable.length,
40 index = CharOperation.hashCode(key) % length;
41 int keyLength = key.length;
42 char[] currentKey;
43 while ((currentKey = this.keyTable[index]) != null) {
44 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
45 return true;
46 if (++index == length) {
47 index = 0;
48 }
49 }
50 return false;
51 }
get(char[] key)52 public ReferenceBinding get(char[] key) {
53 int length = this.keyTable.length,
54 index = CharOperation.hashCode(key) % length;
55 int keyLength = key.length;
56 char[] currentKey;
57 while ((currentKey = this.keyTable[index]) != null) {
58 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
59 return this.valueTable[index];
60 if (++index == length) {
61 index = 0;
62 }
63 }
64 return null;
65 }
66 // Returns old value.
getput(char[] key, ReferenceBinding value)67 public ReferenceBinding getput(char[] key, ReferenceBinding value) {
68 ReferenceBinding retVal = null;
69 int length = this.keyTable.length,
70 index = CharOperation.hashCode(key) % length;
71 int keyLength = key.length;
72 char[] currentKey;
73 while ((currentKey = this.keyTable[index]) != null) {
74 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key)) {
75 retVal = this.valueTable[index];
76 this.valueTable[index] = value;
77 return retVal;
78 }
79 if (++index == length) {
80 index = 0;
81 }
82 }
83 this.keyTable[index] = key;
84 this.valueTable[index] = value;
85
86 // assumes the threshold is never equal to the size of the table
87 if (++this.elementSize > this.threshold)
88 rehash();
89 return retVal;
90 }
put(char[] key, ReferenceBinding value)91 public ReferenceBinding put(char[] key, ReferenceBinding value) {
92 int length = this.keyTable.length,
93 index = CharOperation.hashCode(key) % length;
94 int keyLength = key.length;
95 char[] currentKey;
96 while ((currentKey = this.keyTable[index]) != null) {
97 if (currentKey.length == keyLength && CharOperation.equals(currentKey, key))
98 return this.valueTable[index] = value;
99 if (++index == length) {
100 index = 0;
101 }
102 }
103 this.keyTable[index] = key;
104 this.valueTable[index] = value;
105
106 // assumes the threshold is never equal to the size of the table
107 if (++this.elementSize > this.threshold)
108 rehash();
109 return value;
110 }
rehash()111 private void rehash() {
112 HashtableOfType newHashtable = new HashtableOfType(this.elementSize < 100 ? 100 : this.elementSize * 2); // double the number of expected elements
113 char[] currentKey;
114 for (int i = this.keyTable.length; --i >= 0;)
115 if ((currentKey = this.keyTable[i]) != null)
116 newHashtable.put(currentKey, this.valueTable[i]);
117
118 this.keyTable = newHashtable.keyTable;
119 this.valueTable = newHashtable.valueTable;
120 this.threshold = newHashtable.threshold;
121 }
size()122 public int size() {
123 return this.elementSize;
124 }
125 @Override
toString()126 public String toString() {
127 String s = ""; //$NON-NLS-1$
128 ReferenceBinding type;
129 for (int i = 0, length = this.valueTable.length; i < length; i++)
130 if ((type = this.valueTable[i]) != null)
131 s += type.toString() + "\n"; //$NON-NLS-1$
132 return s;
133 }
134 }
135