Re: [AD] Clarifying and revising filesystem API

[Peter Wang <novalazy@xxxxxxxxxx>]

On 2009-04-17, Elias Pschernig <elias.pschernig@xxxxxxxxxx> wrote:
> Peter Wang wrote:
> > 
> > Let me propose again a URI-like scheme, and strip the API down to
> > stream operations only.
> > 
> > 
> > ## API: al_register_stream_handler
> > 
> >     bool al_register_stream_handler(const char *scheme,
> > 	ALLEGRO_FILE_VTABLE *vtable);
> > 
> > Register a handler for a particular scheme.  The scheme must be a
> > non-empty string, not containing any colon characters, e.g. "file".
> > vtable is a pointer to a table of function pointers.  The functions will
> > be used to operate on the streams which were opened with the particular
> > scheme.
> > 
> > By default, the scheme "file" is registered and is handled using the C
> > library stdio functions.
> 
> Could we have a function to set a per-thread default handler? The use cases I 
> can think of would make things a lot simpler with that as I don't have to mess 
> with prepending schemes to copies of my filename strings all the time. Something 
> like:
> 
> al_set_default_stream_handler(ALLEGRO_FILE_VTABLE *vtable);
> 
> Passing NULL would reset to the builtin one.

I'm not particularly opposed to it, but I don't think prepending is that
hard, using al_ustr_newf() for example.  What cases are you thinking of?

> > ## Writing to a memory block
> > 
> >     /* You need to generate a unique token somehow.
> >      * The addon could help you, or you could follow a convention
> >      * like Java package names.
> >      */
> >     const char *token = "mem:b3457c95-db59-480d-91d0-9d0f61a6e7d1";
> > 
> 
> I find this really confusing... when doing it like this, what is the remaining 
> advantage of using this over the _entry version?

You wouldn't need two versions of every function, the string version and the
_entry version.


Elsewhere:
> My vote also goes for directory operations. It's very common in games (e.g. list 
> all files in the savegames folder).

Ok.  How about we keep directory operations but in a distinct part of the
API?  It wouldn't use ALLEGRO_FILEs and you couldn't hook the functions, so
they would only work with the local disk.  Then the questions about the
current directory would have obvious answers.

Peter