src/protocols/jabber/hashtable.c

   1 /*
   2 The contents of this file are subject to the Mozilla Public License
   3 Version 1.1 (the "License"); you may not use this file except in
   4 csompliance with the License. You may obtain a copy of the License at
   5 http://www.mozilla.org/MPL/
   6
   7 Software distributed under the License is distributed on an "AS IS"
   8 basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
   9 License for the specific language governing rights and limitations
  10 under the License.
  11
  12 The Original Code is expat.
  13
  14 The Initial Developer of the Original Code is James Clark.
  15 Portions created by James Clark are Copyright (C) 1998, 1999
  16 James Clark. All Rights Reserved.
  17
  18 Contributor(s):
  19
  20 Alternatively, the contents of this file may be used under the terms
  21 of the GNU General Public License (the "GPL"), in which case the
  22 provisions of the GPL are applicable instead of those above.  If you
  23 wish to allow use of your version of this file only under the terms of
  24 the GPL and not to allow others to use your version of this file under
  25 the MPL, indicate your decision by deleting the provisions above and
  26 replace them with the notice and other provisions required by the
  27 GPL. If you do not delete the provisions above, a recipient may use
  28 your version of this file under either the MPL or the GPL.
  29 */
  30
  31 #include "xmldef.h"
  32
  33 #ifdef XML_UNICODE_WCHAR_T
  34 #ifndef XML_UNICODE
  35 #define XML_UNICODE
  36 #endif
  37 #endif
  38
  39 #include "hashtable.h"
  40
  41 #define INIT_SIZE 64
  42
  43 static
  44 int keyeq(KEY s1, KEY s2)
  45 {
  46     for (; *s1 == *s2; s1++, s2++)
  47         if (*s1 == 0)
  48             return 1;
  49     return 0;
  50 }
  51
  52 static
  53 unsigned long hash(KEY s)
  54 {
  55     unsigned long h = 0;
  56     while (*s)
  57         h = (h << 5) + h + (unsigned char)*s++;
  58     return h;
  59 }
  60
  61 NAMED *lookup(HASH_TABLE *table, KEY name, size_t createSize)
  62 {
  63     size_t i;
  64     if (table->size == 0) {
  65         if (!createSize)
  66             return 0;
  67         table->v = calloc(INIT_SIZE, sizeof(NAMED *));
  68         if (!table->v)
  69             return 0;
  70         table->size = INIT_SIZE;
  71         table->usedLim = INIT_SIZE / 2;
  72         i = hash(name) & (table->size - 1);
  73     }
  74     else {
  75         unsigned long h = hash(name);
  76         for (i = h & (table->size - 1);
  77                 table->v[i];
  78                 i == 0 ? i = table->size - 1 : --i) {
  79             if (keyeq(name, table->v[i]->name))
  80                 return table->v[i];
  81         }
  82         if (!createSize)
  83             return 0;
  84         if (table->used == table->usedLim) {
  85             /* check for overflow */
  86             size_t newSize = table->size * 2;
  87             NAMED **newV = calloc(newSize, sizeof(NAMED *));
  88             if (!newV)
  89                 return 0;
  90             for (i = 0; i < table->size; i++)
  91                 if (table->v[i]) {
  92                     size_t j;
  93                     for (j = hash(table->v[i]->name) & (newSize - 1);
  94                             newV[j];
  95                             j == 0 ? j = newSize - 1 : --j)
  96                         ;
  97                     newV[j] = table->v[i];
  98                 }
  99             free(table->v);
 100             table->v = newV;
 101             table->size = newSize;
 102             table->usedLim = newSize/2;
 103             for (i = h & (table->size - 1);
 104                     table->v[i];
 105                     i == 0 ? i = table->size - 1 : --i)
 106                 ;
 107         }
 108     }
 109     table->v[i] = calloc(1, createSize);
 110     if (!table->v[i])
 111         return 0;
 112     table->v[i]->name = name;
 113     (table->used)++;
 114     return table->v[i];
 115 }
 116
 117 void hashTableDestroy(HASH_TABLE *table)
 118 {
 119     size_t i;
 120     for (i = 0; i < table->size; i++) {
 121         NAMED *p = table->v[i];
 122         if (p)
 123             free(p);
 124     }
 125     free(table->v);
 126 }
 127
 128 void hashTableInit(HASH_TABLE *p)
 129 {
 130     p->size = 0;
 131     p->usedLim = 0;
 132     p->used = 0;
 133     p->v = 0;
 134 }
 135
 136 void hashTableIterInit(HASH_TABLE_ITER *iter, const HASH_TABLE *table)
 137 {
 138     iter->p = table->v;
 139     iter->end = iter->p + table->size;
 140 }
 141
 142 NAMED *hashTableIterNext(HASH_TABLE_ITER *iter)
 143 {
 144     while (iter->p != iter->end) {
 145         NAMED *tem = *(iter->p)++;
 146         if (tem)
 147             return tem;
 148     }
 149     return 0;
 150 }
 151