Re: int64 support in 64bit architecture

[Xavier Wang <weasley.wx@...>]

So you even don't know the structure of the time stamp? In this way,
you still can not process the time stamp, because you can only process
it if you know which fields is contained in it.
there are another possible about this. you just want "hold" this value
into a int64 variable, and parse it in right time with right people?
in this way, you can make a string from int64 value. my lbuffer module
can handle this (but maybe I need do some modify to this module...).
but if you need large amount of int64 integer, maybe using pointer is
a good method, though it has less portability :-)


在 2012年4月12日 下午12:38，云风 <cloudwu@gmail.com> 写道：
> I don't know whether the time stamp is base 0 , maybe it count from a
> very large number or a random number.
> It used in many place, and the data type defined in protocol is 64bit.
> I can't guarantee it never used on some unusual way. For example, the
> high bits used for machine id in other place. The other parts of
> system don't know the lua limits .
>
> 在 2012年4月12日 上午3:22，Xavier Wang <weasley.wx@gmail.com> 写道：
>> let's think of how many years if you use 56bit integer to indicate time stamp:
>>
>> a year has 60*60*24*365.2422 seconds, i.e. 31556926s.
>>
>> so a 2^32 integer can indicate 2^32/31556926 == 136.10 year,
>>
>> so, if you use 32bit integer and use date from 1900, you will overflow in 2036.
>>
>> but a 2^56 integer can indicate 2^56/31556926 == 2283416130 year,
>>
>> so even you count time in us(1/1000000s), you still can indicate 2283 year.
>>
>> means you can indicate years from 0000 to 2283, which is mostly enough.
>>
>> so, just convert int64 time stamp to lua_Number, it's enough :-)
>>
>> 在 2012年4月12日 上午2:57，云风 <cloudwu@gmail.com> 写道：
>>> It's not enough, because the time stamp is send by other process not
>>> written in lua. The protocol define it is the int64 number.
>>>
>>> 在 2012年4月12日 上午2:05，Xavier Wang <weasley.wx@gmail.com> 写道：
>>>> in this case, 56bit should be enough.
>>>>
>>>> 在 2012年4月12日 上午1:34，云风 <cloudwu@gmail.com> 写道：
>>>>> We use int64 for a timestamp from outside ( read from a socket with
>>>>> the protocol) , and we need preform arithmetic on it.
>>>>>
>>>>> 在 2012年4月11日 下午9:14，Xavier Wang <weasley.wx@gmail.com> 写道：
>>>>>> and then you can put it into a string.
>>>>>>
>>>>>> 在 2012-4-11 晚上8:05，"steve donovan" <steve.j.donovan@gmail.com>写道：
>>>>>>
>>>>>>> On Wed, Apr 11, 2012 at 1:42 PM, Alex Queiroz <asandroq@gmail.com> wrote:
>>>>>>> > Unless it's possible to create the IDs consecutively starting from 1.
>>>>>>>
>>>>>>> But they often come from outside, and Outside has its own logic ;)
>>>>>>>
>>>>>>> steve d.
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> http://blog.codingnow.com
>>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> http://blog.codingnow.com
>>>
>>
>
>
>
> --
> http://blog.codingnow.com
>