tc_register.c

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/*
** Copyright (C) 2004, 2005 by Kevin L. Mitchell <klmitch@mit.edu>
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
**
** @(#)$Id: tc_register.c,v 1.6 2005/06/07 04:53:50 klmitch Exp $
*/
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "treeconf_int.h"

RCSTAG("@(#)$Id: tc_register.c,v 1.6 2005/06/07 04:53:50 klmitch Exp $");

unsigned int
tc_register(treeconf_ctx_t *ctx, const char *name, const char *def,
          treeconf_node_t *parent, treeconf_nodown_t nodown,
          treeconf_change_t change, void *assoc)
{
  treeconf_node_t *node;
  struct result res;
  unsigned int err = 0;
  int i;

  initialize_trcf_error_table();

  /* verify the arguments */
  if (!tx_verify(ctx) || !name ||
      (parent && (!tn_verify(parent) || parent->tn_context != ctx)))
    return EINVAL;

  /* OK, look up the node... */
  if ((err = _tc_lookup_node(ctx, name, parent, &res)))
    return err;

  /* We found the named node... */
  if (res.r_node && res.r_count == res.r_startnew) {
    treeconf_type_t type = (def ? TC_NODETYPE_VARIABLE : TC_NODETYPE_NODE);

    if (!(res.r_node->tn_type & TC_NODETYPE_IMPLICIT) ||
      res.r_node->tn_default)
      _tc_doerror(TC_ERR_MULTREG); /* attempt to multiply-register config... */

    if (def && !(def = strdup(def))) /* alloc default */
      _tc_doerror(ENOMEM);

    /* If there's a type mismatch, release all the down nodes... */
    if (((1 << type) ^ (1 << (res.r_node->tn_type & TC_NODETYPE_MASK))) &&
      res.r_node->tn_down)
      _tc_release_children(res.r_node);

    /* OK, let's set the type... */
    res.r_node->tn_type = type;
    res.r_node->tn_default = def;
    res.r_node->tn_nodown = nodown; /* set the callback variables */
    res.r_node->tn_change = change;
    res.r_node->tn_assoc = assoc; /* set the association data */

    if (def) { /* check the current value against the default... */
      if (!res.r_node->tn_value) /* not set...hmmm... */
      res.r_node->tn_value = def; /* OK, just default it */
      else if (!strcmp(res.r_node->tn_value, def)) {
      /* the default and current value are identical */
      free((void *)res.r_node->tn_value); /* free old value... */
      res.r_node->tn_value = def; /* and default it */
      } else /* value and default don't match; call change routine... */
      _tn_call_change(res.r_node);
    }
  } else /* build new nodes */
    for (i = res.r_startnew, node = res.r_node; i < res.r_count; i++)
      if (!(node = _tc_create_node(ctx, node,
                           (def && i == res.r_count - 1 ?
                            TC_NODETYPE_VARIABLE : TC_NODETYPE_NODE),
                           res.r_comps[i].ts_string,
                           res.r_comps[i].ts_length,
                           (i == res.r_count - 1 ? def : 0),
                           nodown, change, assoc)))
      _tc_doerror(ENOMEM);

  /* Make all implicit nodes up to this point explicit */
  if (res.r_node)
    for (node = (res.r_node->tn_type & TC_NODETYPE_IMPLICIT) ?
         res.r_node : res.r_node->tn_parent;
       node && node->tn_type & TC_NODETYPE_IMPLICIT;
       node = node->tn_parent)
      node->tn_type &= ~TC_NODETYPE_IMPLICIT;

 error:
  free(res.r_comps); /* Release temporarily allocated memory */

  return err;
}

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