Re: Reducing unncessary string copying

[Yasushi SHOJI <yashi atmark-techno com>]

Hi Enrico,

At Mon, 20 Feb 2012 13:08:05 +0100,
Enrico Weigelt wrote:
[...]
> and the call now would be
> 
>     create_foo(G_CSTR_STATIC("hello world"));
> 
> in case we dont have an "static" string, but something with
> limited lifetime, it could look like this:
> 
>     create_foo(G_CSTR_DYNAMIC(bar));
> 
> Inside create_foo() we'll then replace g_strdup() by some
> G_CSTR_COPY() and g_free() by G_CSTR_FREE(). These functions
> will know whether the string has to be copied/free'd.

with all the complication above, what's the benefit of having
G_CSTR_STATIC compared to:

     /* create_foo will hold the passing pointer. do not free() after
      * you passed.  just pass a literal string will do good.
      */
     create_foo("hello world");

or

     create_foo_with_literal_string("hello world");

or

     #define G_CSTR_STATIC(x) x
        :
     create_foo(G_CSTR_STATIC("hello world"));

     /* and remove all g_free() and g_strdup in create_foo() because
      * create_foo will _not_ accept a pointer to dynamic memory
      * location anyway.
      */
?

it sounds, at least to me, more like a convention than new APIs or a
new class.  how many bytes or how many CPU clocks are we waisting in
real world application?

did you have a copy-on-write string class, like std::string in C++, in
your mind?  having a copy-on-write string class in glib might be a
good idea.

I apologize in advance if I'm way off.

with all my respect,
-- 
            yashi