A low-level approach to mutable byte-arrays

[Eduardo Ochs <eduardoochs@...>]

Hi Florian and all,

On Thu, Jun 2, 2011 at 11:56 AM, Florian Weimer <fw@deneb.enyo.de> wrote:

I'm interested in defining a lightweight library for mutable byte
arrays.  I'm attaching a draft.

My goals are these: define something which can be implement reasonably
efficiently in stock Lua 5.1, that is easy to interoperate with at the
C level, and which can be optimized by Lua compilers.  Eventually, I
hope that different libraries will be able to exchange data as byte
arrays instead of strings (where this makes sense), reducing
allocations and avoiding hashing.

The C interface is the main reason why the arrays are not resizable:
Otherwise the address of the underlying memory region could change
while you cling to a reference of the array object.

What do you think about this idea?
(...)

I know that you should be all thinking on something infinitely more

highlevel-ish that what I am going to show, but I can't resist showing

this!... If one is mostly interested in starting with the mininum and

building a prototype around it, then maybe this could help:

  http://angg.twu.net/peek/

  http://angg.twu.net/peek/peek.c.html

From the description in the C file:

  This file implements four very low-level functions.

  They work like this:

       str = peek_(addr, len)

             poke_(addr, str)

    addr = malloc_(len)

             free_(addr)

  where "addr" and "len" are integers, and "str" is a string.

  The functions are placed in the global namespace.

  There is no range checking at all, just like in the old Forth days.

  Have fun! 8-)

Cheers!

  Eduardo Ochs

  eduardoochs@gmail.com

  http://angg.twu.net/