ntptime.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

/* ***** BEGIN LICENSE BLOCK ***** 
 * Version: RCSL 1.0/RPSL 1.0 
 *  
 * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
 *      
 * The contents of this file, and the files included with this file, are 
 * subject to the current version of the RealNetworks Public Source License 
 * Version 1.0 (the "RPSL") available at 
 * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 * the file under the RealNetworks Community Source License Version 1.0 
 * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 * in which case the RCSL will apply. You may also obtain the license terms 
 * directly from RealNetworks.  You may not use this file except in 
 * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 * RCSL for the rights, obligations and limitations governing use of the 
 * contents of the file.  
 *  
 * This file is part of the Helix DNA Technology. RealNetworks is the 
 * developer of the Original Code and owns the copyrights in the portions 
 * it created. 
 *  
 * This file, and the files included with this file, is distributed and made 
 * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS 
 * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * 
 * Technology Compatibility Kit Test Suite(s) Location: 
 *    http://www.helixcommunity.org/content/tck 
 * 
 * Contributor(s): 
 *  
 * ***** END LICENSE BLOCK ***** */ 

// #include "hlxclib/stdio.h"
#include "hlxclib/stdlib.h"
#include "hxtypes.h"
#include "hxstring.h"
#include "hxtime.h"
#include "timeval.h"
#include "ntptime.h"

#ifdef _DEBUG
#undef HX_THIS_FILE		
static const char HX_THIS_FILE[] = __FILE__;
#endif

NTPTime::NTPTime()
{
    // default to now
    Timeval now;
    gettimeofday(&now, 0);
    fromTimeval(now);
}

NTPTime::NTPTime(UINT32 ulSec, UINT32 ulFrac):
    m_ulSecond(ulSec),
    m_ulFraction(ulFrac)
{
}

NTPTime::NTPTime(UINT32 mSec)
{
    fromMSec(mSec);
}

NTPTime::NTPTime(Timeval tv)
{
    fromTimeval(tv);
}

NTPTime::NTPTime(const NTPTime& lhs)
{
    m_ulSecond = lhs.m_ulSecond;
    m_ulFraction = lhs.m_ulFraction;
}

NTPTime&
NTPTime::operator=(const NTPTime& lhs)
{
    m_ulSecond = lhs.m_ulSecond;
    m_ulFraction = lhs.m_ulFraction;
    return *this;
}

INT32
NTPTime::compare(const NTPTime& lhs) const
{
    // I'm sure there's a better way to do this...

    if(m_ulSecond > lhs.m_ulSecond)
    {
	return 1;
    }
    else if(m_ulSecond == lhs.m_ulSecond)
    {
	return (INT32) ((m_ulFraction >> 1) - (lhs.m_ulFraction >> 1));
    }
    return -1;
}

UINT32
NTPTime::toMSec()
{
    // no checking for overflow
    double ms = (m_ulSecond * 1000.0);
    ms += ((double) m_ulFraction / (double) MAX_UINT32) * 1000.0;

    return (UINT32) ms;
}

void
NTPTime::fromMSec(INT32 mSec)
{
    Timeval tv;

    tv.tv_sec = mSec / 1000;
    tv.tv_usec = (mSec % 1000) * 1000;
    fromTimeval(tv);
}

NTPTime::operator UINT32()
{
    return toMSec();
}

NTPTime&
NTPTime::operator+=(const NTPTime& lhs)
{
    m_ulSecond += lhs.m_ulSecond;

    if ((MAX_UINT32 - m_ulFraction + 1) <= lhs.m_ulFraction)
    {
	// No overflow checking
	m_ulSecond++;
	m_ulFraction = lhs.m_ulFraction - (MAX_UINT32 - m_ulFraction + 1);
    }
    else
    {
	m_ulFraction += lhs.m_ulFraction;
    }
    
    return *this;
} 

NTPTime&
NTPTime::operator-=(const NTPTime& lhs)
{
    m_ulSecond -= lhs.m_ulSecond;

    if (m_ulFraction < lhs.m_ulFraction)
    {
	// No underflow checking
	m_ulSecond--;
    }

    m_ulFraction = m_ulFraction - lhs.m_ulFraction;
    
    return *this;
}

NTPTime
NTPTime::operator+(const NTPTime& lhs)
{
    NTPTime tmpTime(*this);
    tmpTime += lhs;
    return tmpTime;
}

NTPTime
NTPTime::operator-(const NTPTime& lhs)
{
    NTPTime tmpTime(*this);
    tmpTime -= lhs;
    return tmpTime;
}