multi.c

刻录光盘的程序

    {
      return NULL;
    }

  pri = (struct iso_primary_descriptor *)vdp;

  /*
   * Check the blocksize of the image to make sure it is compatible.
   */
  if(    (isonum_723 ((unsigned char *) pri->logical_block_size) != SECTOR_SIZE)
      || (isonum_723 ((unsigned char *) pri->volume_set_size) != 1) )
    {
      return NULL;
    }

  /*
   * Get the location and size of the root directory.
   */
  rootp = (struct iso_directory_record *) 
    malloc(sizeof(struct iso_directory_record));

  memcpy(rootp, pri->root_directory_record, sizeof(*rootp));

  return rootp;
}

void FDECL3(merge_remaining_entries, struct directory *, this_dir,
	    struct directory_entry **, pnt,
	    int, n_orig)
{
  int i;
  struct directory_entry * s_entry;
  unsigned int ttbl_extent = 0;
  unsigned int ttbl_index  = 0;
  char whole_path[1024];

  /*
   * Whatever is leftover in the list needs to get merged back
   * into the directory.
   */
  for( i=0; i < n_orig; i++ )
    {
      if( pnt[i] == NULL )
	{
	  continue;
	}
      
      if( pnt[i]->name != NULL && pnt[i]->whole_name == NULL)
       {
         /*
          * Set the name for this directory.
          */
         strcpy(whole_path, this_dir->de_name);
         strcat(whole_path, SPATH_SEPARATOR);
         strcat(whole_path, pnt[i]->name);

         pnt[i]->whole_name = strdup(whole_path);
       }

      if( pnt[i]->name != NULL
/*	  && strcmp(pnt[i]->name, "<translation table>") == 0 )*/
	  && strcmp(pnt[i]->name, trans_tbl) == 0 )
	{
	  ttbl_extent = isonum_733((unsigned char *) pnt[i]->isorec.extent);
	  ttbl_index = i;
	  continue;
	}
      /*
       * Skip directories for now - these need to be treated
       * differently.
       */
      if( (pnt[i]->isorec.flags[0] & 2) != 0 )
	{
	  /*
	   * FIXME - we need to insert this directory into the
	   * tree, so that the path tables we generate will
	   * be correct.
	   */
	  if(    (strcmp(pnt[i]->name, ".") == 0)
	      || (strcmp(pnt[i]->name, "..") == 0) )
	    {
	      free_directory_entry(pnt[i]);
	      pnt[i] = NULL;
	      continue;
	    }
	  else
	    {
	      merge_old_directory_into_tree(pnt[i], this_dir);
	    }
	}
      pnt[i]->next = this_dir->contents;
      pnt[i]->filedir = this_dir;
      this_dir->contents = pnt[i];
      pnt[i] = NULL;
    }
  

  /*
   * If we don't have an entry for the translation table, then
   * don't bother trying to copy the starting extent over.
   * Note that it is possible that if we are copying the entire
   * directory, the entry for the translation table will have already
   * been inserted into the linked list and removed from the old
   * entries list, in which case we want to leave the extent number
   * as it was before.
   */
  if( ttbl_extent == 0 )
    {
      return;
    }

  /*
   * Finally, check the directory we are creating to see whether
   * there are any new entries in it.  If there are not, we can
   * reuse the same translation table.
   */
  for(s_entry = this_dir->contents; s_entry; s_entry = s_entry->next)
    {
      /*
       * Don't care about '.' or '..'.  They are never in the table
       * anyways.
       */
      if( s_entry->name != NULL && strcmp(s_entry->name, ".") == 0 )
	{
	  continue;
	}
      if( s_entry->name != NULL && strcmp(s_entry->name, "..") == 0 )
	{
	  continue;
	}
/*      if( strcmp(s_entry->name, "<translation table>") == 0)*/
      if( strcmp(s_entry->name, trans_tbl) == 0)
	{
	  continue;
	}
      if( (s_entry->de_flags & SAFE_TO_REUSE_TABLE_ENTRY) == 0 )
	{
	  return;
	}
    }

  /*
   * Locate the translation table, and re-use the same extent.
   * It isn't clear that there should ever be one in there already
   * so for now we try and muddle through the best we can.
   */
  for(s_entry = this_dir->contents; s_entry; s_entry = s_entry->next)
    {
/*      if( strcmp(s_entry->name, "<translation table>") == 0)*/
      if( strcmp(s_entry->name, trans_tbl) == 0)
	{
	  fprintf(stderr,"Should never get here\n");
	  set_733(s_entry->isorec.extent, ttbl_extent);
	  return;
	}
    }

  pnt[ttbl_index]->next = this_dir->contents;
  pnt[ttbl_index]->filedir = this_dir;
  this_dir->contents = pnt[ttbl_index];
  pnt[ttbl_index] = NULL;
}


/*
 * Here we have a case of a directory that has completely disappeared from
 * the face of the earth on the tree we are mastering from.  Go through and
 * merge it into the tree, as well as everything beneath it.
 *
 * Note that if a directory has been moved for some reason, this will
 * incorrectly pick it up and attempt to merge it back into the old
 * location.  FIXME(eric).
 */
static int
FDECL2(merge_old_directory_into_tree, struct directory_entry *, dpnt, 
       struct directory *, parent)
{
  struct directory_entry	**contents = NULL;
  int				  i;
  int				  n_orig;
  struct directory		* this_dir, *next_brother;
  char				  whole_path[1024];

  this_dir = (struct directory *) e_malloc(sizeof(struct directory));
  memset(this_dir, 0, sizeof(struct directory));
  this_dir->next = NULL;
  this_dir->subdir = NULL;
  this_dir->self = dpnt;
  this_dir->contents = NULL;
  this_dir->size = 0;
  this_dir->extent = 0;
  this_dir->depth = parent->depth + 1;
  this_dir->parent = parent;
  if(!parent->subdir)
    parent->subdir = this_dir;
  else {
    next_brother = parent->subdir;
    while(next_brother->next) next_brother = next_brother->next;
    next_brother->next = this_dir;
  }

  /*
   * Set the name for this directory.
   */
  strcpy(whole_path, parent->de_name);
  strcat(whole_path, SPATH_SEPARATOR);
  strcat(whole_path, dpnt->name);
  this_dir->de_name = strdup(whole_path);
  this_dir->whole_name = strdup(whole_path);

  /*
   * Now fill this directory using information from the previous
   * session.
   */
  contents = read_merging_directory(&dpnt->isorec, &n_orig);
  /*
   * Start by simply copying the '.', '..' and non-directory
   * entries to this directory.  Technically we could let
   * merge_remaining_entries handle this, but it gets rather confused
   * by the '.' and '..' entries.
   */
  for(i=0; i < n_orig; i ++ )
    {
      /*
       * We can always reuse the TRANS.TBL in this particular case.
       */
      contents[i]->de_flags |= SAFE_TO_REUSE_TABLE_ENTRY;	

      if(    ((contents[i]->isorec.flags[0] & 2) != 0)
	  && (i >= 2) )
	{
	  continue;
	}

      /*
       * If we have a directory, don't reuse the extent number.
       */
      if( (contents[i]->isorec.flags[0] & 2) != 0 )
	{
	  memset(contents[i]->isorec.extent, 0, 8);

	  if( strcmp(contents[i]->name, ".") == 0 )
	      this_dir->dir_flags |= DIR_HAS_DOT;

	  if( strcmp(contents[i]->name, "..") == 0 )
	      this_dir->dir_flags |= DIR_HAS_DOTDOT;
	}

      /*
       * Set the whole name for this file.
       */
      strcpy(whole_path, this_dir->whole_name);
      strcat(whole_path, SPATH_SEPARATOR);
      strcat(whole_path, contents[i]->name);

      contents[i]->whole_name = strdup(whole_path);

      contents[i]->next = this_dir->contents;
      contents[i]->filedir = this_dir;
      this_dir->contents = contents[i];
      contents[i] = NULL;
    }

  /*
   * Zero the extent number for ourselves.
   */
  memset(dpnt->isorec.extent, 0, 8);

  /*
   * Anything that is left are other subdirectories that need to be merged.
   */
  merge_remaining_entries(this_dir, contents, n_orig);
  free_mdinfo(contents, n_orig);
#if 0
  /*
   * This is no longer required.  The post-scan sort will handle
   * all of this for us.
   */
  sort_n_finish(this_dir);
#endif

  return 0;
}


char * cdrecord_data = NULL;

int
FDECL1(get_session_start, int *, file_addr) 
{
  char * pnt;

#ifdef CDRECORD_DETERMINES_FIRST_WRITABLE_ADDRESS
  /*
   * FIXME(eric).  We need to coordinate with cdrecord to obtain
   * the parameters.  For now, we assume we are writing the 2nd session,
   * so we start from the session that starts at 0.
   */

  *file_addr = (16 << 11);

  /*
   * We need to coordinate with cdrecord to get the next writable address
   * from the device.  Here is where we use it.
   */
  session_start = last_extent = last_extent_written = cdrecord_result();

#else

  if( cdrecord_data == NULL )
    {
#ifdef	USE_LIBSCHILY
      comerrno(EX_BAD, "Special parameters for cdrecord not specified with -C\n");
#else
      fprintf(stderr,"Special parameters for cdrecord not specified with -C\n");
      exit(1);
#endif
    }

  /*
   * Next try and find the ',' in there which delimits the two numbers.
   */
  pnt = strchr(cdrecord_data, ',');
  if( pnt == NULL )
    {
#ifdef	USE_LIBSCHILY
      comerrno(EX_BAD, "Malformed cdrecord parameters\n");
#else
      fprintf(stderr, "Malformed cdrecord parameters\n");
      exit(1);
#endif
    }

  *pnt = '\0';
  if (file_addr != NULL) {
    *file_addr = atol(cdrecord_data) * SECTOR_SIZE;
  }
  pnt++;

  session_start = last_extent = last_extent_written = atol(pnt);

  pnt--;
  *pnt = ',';

#endif
  return 0;
}

/*
 * This function scans the directory tree, looking for files, and it makes
 * note of everything that is found.  We also begin to construct the ISO9660
 * directory entries, so that we can determine how large each directory is.
 */

int
FDECL2(merge_previous_session,struct directory *, this_dir,
       struct iso_directory_record *, mrootp)
{
  struct directory_entry	**orig_contents = NULL;
  struct directory_entry        * odpnt = NULL;
  int				  n_orig;
  struct directory_entry	* s_entry;
  int				  status, lstatus;
  struct stat			  statbuf, lstatbuf;
  int 				  retcode;

  /*
   * Parse the same directory in the image that we are merging
   * for multisession stuff.
   */
  orig_contents = read_merging_directory(mrootp, &n_orig);
  if( orig_contents == NULL )
    {
      return 0;
    }


/* Now we scan the directory itself, and look at what is inside of it. */

  for(s_entry = this_dir->contents; s_entry; s_entry = s_entry->next)
    {
      status  =  stat_filter(s_entry->whole_name, &statbuf);
      lstatus = lstat_filter(s_entry->whole_name, &lstatbuf);

      /*
       * We always should create an entirely new directory tree whenever
       * we generate a new session, unless there were *no* changes whatsoever
       * to any of the directories, in which case it would be kind of pointless
       * to generate a new session.
       *
       * I believe it is possible to rigorously prove that any change anywhere
       * in the filesystem will force the entire tree to be regenerated
       * because the modified directory will get a new extent number.  Since
       * each subdirectory of the changed directory has a '..' entry, all of
       * them will need to be rewritten too, and since the parent directory
       * of the modified directory will have an extent pointer to the directory
       * it too will need to be rewritten.  Thus we will never be able to reuse
       * any directory information when writing new sessions.
       *
       * We still check the previous session so we can mark off the equivalent
       * entry in the list we got from the original disc, however.
       */

      /*
       * The check_prev_session function looks for an identical entry in
       * the previous session.  If we see it, then we copy the extent
       * number to s_entry, and cross it off the list. It returns 2 if it's a directory
       */
      retcode = check_prev_session(orig_contents, n_orig, s_entry,
			 &statbuf, &lstatbuf, &odpnt);
      if (retcode == -1)
	return (-1);

      if(retcode==2 && odpnt != NULL)
	{
	  int dflag;

	  if (strcmp(s_entry->name,".") != 0 && strcmp(s_entry->name,"..") != 0)
	    {
	      struct directory * child;

		/*
		 * XXX It seems that the tree that has been read from the
		 * XXX previous session does not carry whole_name entries.
		 * XXX We provide a hack in multi.c:find_or_create_directory()
		 * XXX that should be removed when a reasonable method could
		 * XXX be found.
		 */
	      child = find_or_create_directory(this_dir, 
					       s_entry->whole_name, 
					       s_entry, 1);
	      dflag = merge_previous_session(child, 
					     &odpnt->isorec);
	      if (dflag == -1)
		return (-1);

	      free(odpnt);
	      odpnt = NULL;
	    }
	}
    }
  
  /*
   * Whatever is left over, are things which are no longer in the tree
   * on disk.  We need to also merge these into the tree.
   */
   merge_remaining_entries(this_dir, orig_contents, n_orig);
   free_mdinfo(orig_contents, n_orig);
  
  return 1;
}