JavaScriptCore/runtime/DateInstance.cpp

/*
 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
 *  Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 *  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 "config.h"
#include "DateInstance.h"

#include "DateMath.h"
#include <math.h>
#include <wtf/MathExtras.h>

namespace JSC {

struct DateInstance::Cache {
    double m_gregorianDateTimeCachedForMS;
    GregorianDateTime m_cachedGregorianDateTime;
    double m_gregorianDateTimeUTCCachedForMS;
    GregorianDateTime m_cachedGregorianDateTimeUTC;
};

const ClassInfo DateInstance::info = {"Date", 0, 0, 0};

DateInstance::DateInstance(PassRefPtr<StructureID> structure)
    : JSWrapperObject(structure)
    , m_cache(0)
{
}

DateInstance::~DateInstance()
{
    delete m_cache;
}

void DateInstance::msToGregorianDateTime(double milli, bool outputIsUTC, GregorianDateTime& t) const
{
    if (!m_cache) {
        m_cache = new Cache;
        m_cache->m_gregorianDateTimeCachedForMS = NaN;
        m_cache->m_gregorianDateTimeUTCCachedForMS = NaN;
    }

    if (outputIsUTC) {
        if (m_cache->m_gregorianDateTimeUTCCachedForMS != milli) {
            JSC::msToGregorianDateTime(milli, true, m_cache->m_cachedGregorianDateTimeUTC);
            m_cache->m_gregorianDateTimeUTCCachedForMS = milli;
        }
        t.copyFrom(m_cache->m_cachedGregorianDateTimeUTC);
    } else {
        if (m_cache->m_gregorianDateTimeCachedForMS != milli) {
            JSC::msToGregorianDateTime(milli, false, m_cache->m_cachedGregorianDateTime);
            m_cache->m_gregorianDateTimeCachedForMS = milli;
        }
        t.copyFrom(m_cache->m_cachedGregorianDateTime);
    }
}

bool DateInstance::getTime(GregorianDateTime& t, int& offset) const
{
    double milli = internalNumber();
    if (isnan(milli))
        return false;
    
    msToGregorianDateTime(milli, false, t);
    offset = gmtoffset(t);
    return true;
}

bool DateInstance::getUTCTime(GregorianDateTime& t) const
{
    double milli = internalNumber();
    if (isnan(milli))
        return false;
    
    msToGregorianDateTime(milli, true, t);
    return true;
}

bool DateInstance::getTime(double& milli, int& offset) const
{
    milli = internalNumber();
    if (isnan(milli))
        return false;
    
    GregorianDateTime t;
    msToGregorianDateTime(milli, false, t);
    offset = gmtoffset(t);
    return true;
}

bool DateInstance::getUTCTime(double& milli) const
{
    milli = internalNumber();
    if (isnan(milli))
        return false;
    
    return true;
}

} // namespace JSC