/* Copyright (C) 1995-1996,1998-2001,2003,2006,2008-2009,2011,2018
 *   Free Software Foundation, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 3 of
 * the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */



#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdio.h>

#include "libguile/__scm.h"
#include "libguile/gc.h"
#include "libguile/chooks.h"


/* C level hooks
 *
 */

/* Hint for `scm_gc_malloc ()' and friends.  */
static const char hook_entry_gc_hint[] = "hook entry";

void
scm_c_hook_init (scm_t_c_hook *hook, void *hook_data, scm_t_c_hook_type type)
{
  hook->first = 0;
  hook->type = type;
  hook->data = hook_data;
}

void
scm_c_hook_add (scm_t_c_hook *hook,
		scm_t_c_hook_function func,
		void *fn_data, 
		int appendp)
{
  scm_t_c_hook_entry *entry;
  scm_t_c_hook_entry **loc = &hook->first;

  entry = scm_gc_malloc (sizeof (scm_t_c_hook_entry), hook_entry_gc_hint);
  if (appendp)
    while (*loc)
      loc = &(*loc)->next;
  entry->next = *loc;
  entry->func = func;
  entry->data = fn_data;
  *loc = entry;
}

void
scm_c_hook_remove (scm_t_c_hook *hook,
		   scm_t_c_hook_function func,
		   void *fn_data)
{
  scm_t_c_hook_entry **loc = &hook->first;
  while (*loc)
    {
      if ((*loc)->func == func && (*loc)->data == fn_data)
	{
	  *loc = (*loc)->next;
	  return;
	}
      loc = &(*loc)->next;
    }
  fprintf (stderr, "Attempt to remove non-existent hook function\n");
  abort ();
}

void *
scm_c_hook_run (scm_t_c_hook *hook, void *data)
{
  scm_t_c_hook_entry *entry = hook->first;
  scm_t_c_hook_type type = hook->type;
  void *res = 0;
  while (entry)
    {
      res = (entry->func) (hook->data, entry->data, data);
      if (res)
	{
	  if (type == SCM_C_HOOK_OR)
	    break;
	}
      else
	{
	  if (type == SCM_C_HOOK_AND)
	    break;
	}
      entry = entry->next;
    }
  return res;
}

/*
  Local Variables:
  c-file-style: "gnu"
  End:
*/