xpcom/glue/nsTHashtable.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is C++ hashtable templates.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Benjamin Smedberg.
  19  * Portions created by the Initial Developer are Copyright (C) 2002
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "nsTHashtable.h"
  39 #include "nsHashKeys.h"
  40 #include "prbit.h"
  41
  42 PRUint32
  43 HashString( const nsAString& aStr )
  44 {
  45   PRUint32 code = 0;
  46
  47 #ifdef MOZILLA_INTERNAL_API
  48   nsAString::const_iterator begin, end;
  49   aStr.BeginReading(begin);
  50   aStr.EndReading(end);
  51 #else
  52   const PRUnichar *begin, *end;
  53   PRUint32 len = NS_StringGetData(aStr, &begin);
  54   end = begin + len;
  55 #endif
  56
  57   while (begin != end) {
  58     code = PR_ROTATE_LEFT32(code, 4) ^ PRUint32(*begin);
  59     ++begin;
  60   }
  61
  62   return code;
  63 }
  64
  65 PRUint32
  66 HashString( const nsACString& aStr )
  67 {
  68   PRUint32 code = 0;
  69
  70 #ifdef MOZILLA_INTERNAL_API
  71   nsACString::const_iterator begin, end;
  72   aStr.BeginReading(begin);
  73   aStr.EndReading(end);
  74 #else
  75   const char *begin, *end;
  76   PRUint32 len = NS_CStringGetData(aStr, &begin);
  77   end = begin + len;
  78 #endif
  79
  80   while (begin != end) {
  81     code = PR_ROTATE_LEFT32(code, 4) ^ PRUint32(*begin);
  82     ++begin;
  83   }
  84
  85   return code;
  86 }
  87
  88 PRUint32
  89 HashString(const char *str)
  90 {
  91   PRUint32 code = 0;
  92
  93   while (*str) {
  94     code = PR_ROTATE_LEFT32(code, 4) ^ PRUint32(*str);
  95     ++str;
  96   }
  97
  98   return code;
  99 }
 100
 101 PRUint32
 102 HashString(const PRUnichar *str)
 103 {
 104   PRUint32 code = 0;
 105
 106   while (*str) {
 107     code = PR_ROTATE_LEFT32(code, 4) ^ PRUint32(*str);
 108     ++str;
 109   }
 110
 111   return code;
 112 }
 113
 114 PLDHashOperator
 115 PL_DHashStubEnumRemove(PLDHashTable    *table,
 116                                        PLDHashEntryHdr *entry,
 117                                        PRUint32         ordinal,
 118                                        void            *userarg)
 119 {
 120   return PL_DHASH_REMOVE;
 121 }
 122
 123 PRUint32 nsIDHashKey::HashKey(const nsID* id)
 124 {
 125   PRUint32 h = id->m0;
 126   PRUint32 i;
 127
 128   h = PR_ROTATE_LEFT32(h, 4) ^ id->m1;
 129   h = PR_ROTATE_LEFT32(h, 4) ^ id->m2;
 130
 131   for (i = 0; i < 8; i++)
 132     h = PR_ROTATE_LEFT32(h, 4) ^ id->m3[i];
 133
 134   return h;
 135 }