kjs/lookup.cpp

   1 // -*- c-basic-offset: 2 -*-
   2 /*
   3  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
   4  *  Copyright (C) 2003, 2007 Apple Inc. All rights reserved.
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation; either
   9  *  version 2 of the License, or (at your option) any later version.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #include "config.h"
  23 #include "lookup.h"
  24
  25 #include <wtf/Assertions.h>
  26
  27 namespace KJS {
  28
  29 static inline bool keysMatch(const UChar* c, unsigned len, const char* s)
  30 {
  31   // FIXME: This can run off the end of |s| if |c| has a U+0000 character in it.
  32   const char* end = s + len;
  33   for (; s != end; c++, s++)
  34     if (c->uc != *s)
  35       return false;
  36   return *s == 0;
  37 }
  38
  39 static inline const HashEntry* findEntry(const struct HashTable* table, unsigned int hash,
  40                                          const UChar* c, unsigned int len)
  41 {
  42   ASSERT(table->type == 3);
  43
  44   const HashEntry* e = &table->entries[hash & table->hashSizeMask];
  45
  46   if (!e->s)
  47     return 0;
  48
  49   do {
  50     // compare strings
  51     if (keysMatch(c, len, e->s))
  52       return e;
  53
  54     // try next bucket
  55     e = e->next;
  56   } while (e);
  57   return 0;
  58 }
  59
  60 const HashEntry* Lookup::findEntry(const struct HashTable* table, const Identifier& s)
  61 {
  62   return KJS::findEntry(table, s.ustring().rep()->computedHash(), s.data(), s.size());
  63 }
  64
  65 int Lookup::find(const struct HashTable *table, const UChar *c, unsigned int len)
  66 {
  67   const HashEntry *entry = KJS::findEntry(table, UString::Rep::computeHash(c, len), c, len);
  68   if (entry)
  69     return entry->value.intValue;
  70   return -1;
  71 }
  72
  73 int Lookup::find(const struct HashTable* table, const Identifier& s)
  74 {
  75   const HashEntry* entry = KJS::findEntry(table, s.ustring().rep()->computedHash(), s.data(), s.size());
  76   if (entry)
  77     return entry->value.intValue;
  78   return -1;
  79 }
  80
  81 }