/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
 *  Copyright (C) 2003 Apple Computer, Inc.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "lookup.h"

#include <string.h>

#include <wtf/Assertions.h>

using namespace KJS;

static inline bool keysMatch(const UChar *c, unsigned len, const char *s)
{
    const char *end = s + len;
    for (; s != end; c++, s++)
        if (c->uc != (unsigned char)*s) {
            return false;
        }
    return *s == 0;
}

static inline const HashEntry *findEntry(const struct HashTable *table, unsigned int hash,
        const UChar *c, unsigned int len)
{
#ifndef NDEBUG
    if (table->type != 2) {
        fprintf(stderr, "KJS: Unknown hash table version.\n");
        return nullptr;
    }
#endif
    ASSERT(table->hashSize != 0);

    hash %= table->hashSize;

    const HashEntry *e = &table->entries[hash];

    // empty bucket ?
    if (!e->s) {
        return nullptr;
    }

    do {
        // compare strings
        if (keysMatch(c, len, e->s)) {
            return e;
        }

        // try next bucket
        e = e->next;
    } while (e);
    return nullptr;
}

const HashEntry *Lookup::findEntry(const struct HashTable *table,
                                   const Identifier &s)
{
    const HashEntry *entry = ::findEntry(table, s.ustring().rep()->hash(), s.data(), s.size());
    return entry;
}

int Lookup::find(const struct HashTable *table,
                 const UChar *c, unsigned int len)
{
    const HashEntry *entry = ::findEntry(table, UString::Rep::computeHash(c, len), c, len);
    if (entry) {
        return entry->value;
    }
    return -1;
}

int Lookup::find(const struct HashTable *table, const Identifier &s)
{
    //printf("looking for:%s\n", s.ascii());
    const HashEntry *entry = ::findEntry(table, s.ustring().rep()->hash(), s.data(), s.size());
    if (entry) {
        return entry->value;
    }
    return -1;
}
