/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include "glib.h"


typedef struct _GRealListAllocator GRealListAllocator;

struct _GRealListAllocator
{
  GMemChunk *list_mem_chunk;
  GSList    *free_list;
};


static GRealListAllocator *default_allocator = NULL;
static GRealListAllocator *current_allocator = NULL;

GListAllocator*
g_slist_set_allocator (GListAllocator* fallocator)
{
  GRealListAllocator* allocator = (GRealListAllocator *) fallocator;
  GRealListAllocator* old_allocator = current_allocator;

  if (allocator)
    current_allocator = allocator;
  else
    {
      if (!default_allocator)
	default_allocator = (GRealListAllocator*) g_list_allocator_new ();
      current_allocator = default_allocator;
    }

  if (!current_allocator->list_mem_chunk)
    current_allocator->list_mem_chunk = g_mem_chunk_new ("slist mem chunk",
							 sizeof (GSList),
							 1024,
							 G_ALLOC_ONLY);

  return (GListAllocator*) (old_allocator == default_allocator ? NULL : old_allocator);
}


GSList*
g_slist_alloc ()
{
  GSList *new_list;

  g_slist_set_allocator (NULL);
  if (current_allocator->free_list)
    {
      new_list = current_allocator->free_list;
      current_allocator->free_list = current_allocator->free_list->next;
    }
  else
    {
      new_list = g_chunk_new (GSList, current_allocator->list_mem_chunk);
    }

  new_list->data = NULL;
  new_list->next = NULL;

  return new_list;
}

void
g_slist_free (GSList *list)
{
  GSList *last;

  if (list)
    {
      last = g_slist_last (list);
      last->next = current_allocator->free_list;
      current_allocator->free_list = list;
    }
}

void
g_slist_free_1 (GSList *list)
{
  if (list)
    {
      list->next = current_allocator->free_list;
      current_allocator->free_list = list;
    }
}

GSList*
g_slist_append (GSList   *list,
		gpointer  data)
{
  GSList *new_list;
  GSList *last;

  new_list = g_slist_alloc ();
  new_list->data = data;

  if (list)
    {
      last = g_slist_last (list);
      /* g_assert (last != NULL); */
      last->next = new_list;

      return list;
    }
  else
      return new_list;
}

GSList*
g_slist_prepend (GSList   *list,
		 gpointer  data)
{
  GSList *new_list;

  new_list = g_slist_alloc ();
  new_list->data = data;
  new_list->next = list;

  return new_list;
}

GSList*
g_slist_insert (GSList   *list,
		gpointer  data,
		gint      position)
{
  GSList *prev_list;
  GSList *tmp_list;
  GSList *new_list;

  if (position < 0)
    return g_slist_append (list, data);
  else if (position == 0)
    return g_slist_prepend (list, data);

  new_list = g_slist_alloc ();
  new_list->data = data;

  if (!list)
    return new_list;

  prev_list = NULL;
  tmp_list = list;

  while ((position-- > 0) && tmp_list)
    {
      prev_list = tmp_list;
      tmp_list = tmp_list->next;
    }

  if (prev_list)
    {
      new_list->next = prev_list->next;
      prev_list->next = new_list;
    }
  else
    {
      new_list->next = list;
      list = new_list;
    }

  return list;
}

GSList *
g_slist_concat (GSList *list1, GSList *list2)
{
  if (list2)
    {
      if (list1)
	g_slist_last (list1)->next = list2;
      else
	list1 = list2;
    }

  return list1;
}

GSList*
g_slist_remove (GSList   *list,
		gpointer  data)
{
  GSList *tmp;
  GSList *prev;

  prev = NULL;
  tmp = list;

  while (tmp)
    {
      if (tmp->data == data)
	{
	  if (prev)
	    prev->next = tmp->next;
	  if (list == tmp)
	    list = list->next;

	  tmp->next = NULL;
	  g_slist_free (tmp);

	  break;
	}

      prev = tmp;
      tmp = tmp->next;
    }

  return list;
}

GSList*
g_slist_remove_link (GSList *list,
		     GSList *link)
{
  GSList *tmp;
  GSList *prev;

  prev = NULL;
  tmp = list;

  while (tmp)
    {
      if (tmp == link)
	{
	  if (prev)
	    prev->next = tmp->next;
	  if (list == tmp)
	    list = list->next;

	  tmp->next = NULL;
	  break;
	}

      prev = tmp;
      tmp = tmp->next;
    }

  return list;
}

GSList*
g_slist_reverse (GSList *list)
{
  GSList *tmp;
  GSList *prev;
  GSList *last;

  last = NULL;
  prev = NULL;

  while (list)
    {
      last = list;

      tmp = list->next;
      list->next = prev;

      prev = list;
      list = tmp;
    }

  return last;
}

GSList*
g_slist_nth (GSList *list,
	     gint    n)
{
  while ((n-- > 0) && list)
    list = list->next;

  return list;
}

GSList*
g_slist_find (GSList   *list,
	      gpointer  data)
{
  while (list)
    {
      if (list->data == data)
	break;
      list = list->next;
    }

  return list;
}

GSList*
g_slist_last (GSList *list)
{
  if (list)
    {
      while (list->next)
	list = list->next;
    }

  return list;
}

gint
g_slist_length (GSList *list)
{
  gint length;

  length = 0;
  while (list)
    {
      length++;
      list = list->next;
    }

  return length;
}

void
g_slist_foreach (GSList   *list,
		 GFunc     func,
		 gpointer  user_data)
{
  while (list)
    {
      (*func) (list->data, user_data);
      list = list->next;
    }
}

GSList*
g_slist_insert_sorted (GSList    *list,
                       gpointer  data,
                       GCompareFunc  func)
{
  GSList *tmp_list = list;
  GSList *prev_list = NULL;
  GSList *new_list;
  gint cmp;
 
  if (!list)
    {
      new_list = g_slist_alloc();
      new_list->data = data;
      return new_list;
    }
 
  cmp = (*func) (tmp_list->data, data);
 
  while ((tmp_list->next) && (cmp > 0))
    {
      prev_list = tmp_list;
      tmp_list = tmp_list->next;
      cmp = (*func) (tmp_list->data, data);
    }

  if (cmp == 0)
    return list;
 
  new_list = g_slist_alloc();
  new_list->data = data;

  if ((!tmp_list->next) && (cmp > 0))
    {
      tmp_list->next = new_list;
      return list;
    }
  
  if (prev_list)
    {
      prev_list->next = new_list;
      new_list->next = tmp_list;
      return list;
    }
  else
    {
      new_list->next = list;
      return new_list;
    }
}