[Libcdio-devel] Joliet translated names

[R. Bernstein]

I just looked at the problem you reported in more detail and thought
about it some more. I think the most fool-proof and simplest solution
would to change vfs_smbcdio.c to record the translation such as by
using a hash table.

In more detail, inside procedure smbcdio_stat() in the loop that
processes iso9660_ifs_readdir, a hash table can map the translated
name back into the original ISO 9660 name reported. It would also
catch a problems when several names translate to the same string.  I
believe this happen and it should probably be handled. For example, if
there is foo.txt;1 and foo.txt;2 - do you want both files to be listed
or the latest revision (which I think is foo.txt;2).

Here's some skeleton code for changing vfs_smbcdio.c to use a glib hash table 
to accomplish
the above:

   ...
   #include <glib-2.0/glib.h>
    ...
   GHashTable *iso_files = g_hash_table_new(g_str_hash, g_str_equal);
   ...
   if (g_hash_table_lookup(iso_files, translated_name)) {
      /* Do whatever you want to do on duplicate filenames. This might happen. 
*/ 
      ...
   } else {
      /* insert the new value */
      g_hash_table_insert(iso_files, g_strdup(translated_name), 
g_strdup(iso_name));
   }
   ...

And then in smbcdio_open():

  char *iso_filename = g_hash_table_lookup(iso_files, filename);
  if (iso_filename) {
    cdiostat = iso9660_ifs_stat(p_iso, iso_filename);
    ...

For information on using glib2, see
http://developer.gnome.org/doc/API/glib/ or
http://www-128.ibm.com/developerworks/linux/library/l-glib2.html


If you want me to try to modify the vfs_smbcdio.c code using the above
approach let me know.  Going this route, would require folks to have
glib installed which I don't think is a bad idea -- I have a dream
that libcdio would one day use it as well.

Chris Lalancette writes:
 > All,
 >     I have a question about using the libcdio library, that I just
 > can't seem to figure out by looking at the documentation/examples.
 > Let me lay out the situation:
 > 
 > I am updating a Samba VFS module to use libcdio to access CD devices
 > without mounting them.  What the Samba VFS module does is provide all
 > of the "filesystem" system calls; i.e. opendir, readdir, closedir,
 > open, read, write, close, stat, etc. (obviously for CDROM only the
 > read ones work).  So far I have it so that when opendir is called, I
 > use libcdio to find the directory in question, and build up a linked
 > list of entries.  When a readdir is called, I then "pop" one of those
 > entries off.  This works all well and good, as long as I do not use
 > "translated" names.  That is, if I build the linked list with ISO9660
 > (not Joliet) names, when a readdir happens, I return a name like
 > "foo.txt;1", and then that name gets passed back in to a stat(), or
 > open(), or whatever, and works fine.  If I use the name returned from
 > "iso9660_name_translate_ext()", then the stat() or open() cannot find
 > the name.  Basically I think I need an "untranslate", but I'm not
 > quite sure how to go about that.  Is there something obvious I am
 > missing here, or that I am going about in the wrong way?  If you want
 > to see an older version of the code (which exhibits the same
 > problems), please look at
 > http://www.ontologistics.net/OpenSource/Samba/index.php
 > 
 > Thanks for your help,
 > Chris Lalancette
 > 
 > 
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