kjs Library API Documentation

lookup.cpp

00001 // -*- c-basic-offset: 2 -*-
00002 /*
00003  *  This file is part of the KDE libraries
00004  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
00005  *
00006  *  This library is free software; you can redistribute it and/or
00007  *  modify it under the terms of the GNU Lesser General Public
00008  *  License as published by the Free Software Foundation; either
00009  *  version 2 of the License, or (at your option) any later version.
00010  *
00011  *  This library is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  *  Lesser General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU Lesser General Public
00017  *  License along with this library; if not, write to the Free Software
00018  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00019  *
00020  *  $Id: lookup.cpp,v 1.11 2002/06/19 08:21:00 domi Exp $
00021  */
00022 
00023 #include <stdio.h>
00024 #include <string.h>
00025 
00026 #include "lookup.h"
00027 
00028 #ifdef HAVE_CONFIG_H
00029 #include <config.h>
00030 #endif
00031 
00032 using namespace KJS;
00033 
00034 const HashEntry* Lookup::findEntry( const struct HashTable *table,
00035                               const UChar *c, unsigned int len )
00036 {
00037   if (table->type != 2) {
00038     fprintf(stderr, "KJS: Unknown hash table version.\n");
00039     return 0;
00040   }
00041   char *ascii = new char[len+1];
00042   unsigned int i;
00043   for(i = 0; i < len; i++, c++) {
00044     if (!c->high())
00045       ascii[i] = c->low();
00046     else
00047       break;
00048   }
00049   ascii[i] = '\0';
00050 
00051   int h = hash(ascii) % table->hashSize;
00052   const HashEntry *e = &table->entries[h];
00053 
00054   // empty bucket ?
00055   if (!e->s) {
00056     delete [] ascii;
00057     return 0;
00058   }
00059 
00060   do {
00061     // compare strings
00062     if (strcmp(ascii, e->s) == 0) {
00063       delete [] ascii;
00064       return e;
00065     }
00066     // try next bucket
00067     e = e->next;
00068   } while (e);
00069 
00070   delete [] ascii;
00071   return 0;
00072 }
00073 
00074 const HashEntry* Lookup::findEntry( const struct HashTable *table,
00075                                 const UString &s )
00076 {
00077   return findEntry( table, s.data(), s.size() );
00078 }
00079 
00080 int Lookup::find(const struct HashTable *table,
00081                  const UChar *c, unsigned int len)
00082 {
00083   const HashEntry *entry = findEntry( table, c, len );
00084   if (entry)
00085     return entry->value;
00086   return -1;
00087 }
00088 
00089 int Lookup::find(const struct HashTable *table, const UString &s)
00090 {
00091   return find(table, s.data(), s.size());
00092 }
00093 
00094 unsigned int Lookup::hash(const UChar *c, unsigned int len)
00095 {
00096   unsigned int val = 0;
00097   // ignoring higher byte
00098   for (unsigned int i = 0; i < len; i++, c++)
00099     val += c->low();
00100 
00101   return val;
00102 }
00103 
00104 unsigned int Lookup::hash(const UString &key)
00105 {
00106   return hash(key.data(), key.size());
00107 }
00108 
00109 unsigned int Lookup::hash(const char *s)
00110 {
00111   unsigned int val = 0;
00112   while (*s)
00113     val += *s++;
00114 
00115   return val;
00116 }
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This file is part of the documentation for kdelibs Version 3.1.5.
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