Re: alien question: how to get the address of a buffer object?

[Fabio Mascarenhas <mascarenhas@...>]

Hi,

The only way right now is to use another buffer:

buf = alien.buffer()
buf2 = alien.buffer(4) -- for 32 bit pointers
buf2:set(0, buf:topointer(), "pointer")
buf2:get(0, "int") -- this returns the integer value of the pointer

Of course you can reuse buf2 to get the address of other buffers. But
remember that you have to keep a reference to the original buffer or
Lua may collect it.

BTW, have you thought about using a buffer instead of struct.pack?
struct.pack lets you pack a whole structure as a one-liner, but using
a buffer makes it easier to understand what the code is doing, IMHO (I
use buffers on the struct implementation that I am [slowly] working
on, at https://github.com/mascarenhas/alien/tree).

--
Fabio Mascarenhas




On Sun, Jul 26, 2009 at 1:18 PM, Cosmin
Apreutesei<cosmin.apreutesei@gmail.com> wrote:
> Hi,
>
> Is there a way to get the address of a buffer object? I need to store
> the address of a buffer in a structure that I'll pack with
> alien.struct.pack. The only solution I have found till now involves
> creating another buffer just to store and later retrieve the address
> of the first one.
>
> Thanks,
> Cosmin.
>
> PS: Hope it's ok to ask questions related to lua libraries on this
> list (or should I go to luaforge?)
>