From: Wincent Colaiuta <win@...>
Date: 2008-02-07T03:09:56+09:00
Subject: Re: Avoiding memcpy() during String creation in a C extensio

On 6 feb, 18:46, Tim Hunter <rmag...@gmail.com> wrote:
> Wincent Colaiuta wrote:
>
> > Basically what I would like is a String instantiation method which
> > could take a pointer to a buffer and basically take ownership of that
> > buffer instead of calling memcpy() on it.
>
> > I've looked in string.c to see if such a function exists and it
> > appears that it does not.
>
> Instead of putting your data into a buffer and then asking Ruby to make
> a String out of it, could you use rb_str_buf_new() to create a String
> with a specific capacity and then put your data into the String's
> buffer?

Thanks, Tim.

That would indeed work I think. Didn't know about that function but it
will come in very handy I think. And if the buffer needs to grow as I
append output to it then rb_str_cat should be relatively efficient (I
certainly noticed a huge speed-up when I started using rb_str_cat with
raw buffers rather than creating new Ruby Strings and using
rb_str_append).

Cheers,
Wincent