Re: [lwip-users] Dealloc in fs_close_custom()?

[Giuseppe Modugno]

Il 27/02/2018 08:54, Giuseppe Modugno ha scritto:
> Il 27/02/2018 06:36, Simon Goldschmidt ha scritto:
> > Giuseppe Modugno wrote:
> > > And another thing I couldn't explain. The example uses pextension 
> > > pointer for malloc/free. However it sets file->data = 
> > > file->pextension immediately.
> > >   So why don't use just file->data? It seems pextension is never 
> > > used in lwip code.
> > Exactly. This is an example that wants to show you can use pextension 
> > for anything you like
> > as it is not used by lwIP code internally.
> >
> > Using ->data only works for files in one piece.
> Maybe I'm wrong, but here pextension and state void pointers are very, 
> very similar. Maybe it's possible to reduce the complexity leaving 
> only one member.

Considering the new prototype of httpd_cgi_handler(), this is more 
evident. Now we have struct fs_file pointer in CGI handler, so we can 
access ->pextension (that could be setup during fs_custom_open()). So 
the complexity of LWIP_HTTPD_FILE_STATE is IMHO completely useless.

int fs_open_custom(struct fs_file *file, const char *filename) {
  if (!strcmp(filename, "/custom.html")) {
    struct mystate_s *file_state = mem_malloc(sizeof(struct mystate_s));
    /* Init file_state members */
    file->pextension = file_state;
  }
}

void httpd_cgi_handler(struct fs_file *file, const char *uri, int 
iNumParams, char **pcParam, char **pcValue) {
  struct mystate_s *file_state = (struct mystate_s *)file->pextension;
  /* Access file_state members */
}

void fs_close_custom(struct fs_file *file) {
  if (file && file->pextension) mem_free(file->pextension);
  if (file) mem_free(file);
}