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Java > Open Source Codes > org > eclipse > ui > internal > texteditor > quickdiff > compare > equivalence > DJBHashFunction


1 /*******************************************************************************
2  * Copyright (c) 2005 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  * IBM Corporation - initial API and implementation
10  *******************************************************************************/
11 package org.eclipse.ui.internal.texteditor.quickdiff.compare.equivalence;
12
13 /**
14  *
15  * @since 3.2
16  */
17 public final class DJBHashFunction implements IHashFunction {
18
19     public Hash computeHash(CharSequence JavaDoc string) {
20         return new IntHash(hash(string));
21     }
22     
23     private int hash(CharSequence JavaDoc seq){
24         int hash = 5381;
25         int len= seq.length();
26         for (int i= 0; i < len; i++) {
27             char ch= seq.charAt(i);
28             hash = ((hash << 5) + hash) + ch; /* hash * 33 + ch */
29         }
30
31         return hash;
32     }
33
34 }
35
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