/*****************************************************************************
 *
 *  @File:   LIST.C - C Based List C File
 *  @Author: Marcus Kellerman
 *
 *  Broadcom Corporation Confidential
 *  Copyright 2000 - All Rights Reserved.
 *
 ****************************************************************************/

#include "genericlist.h"

/*******************************************************************************
** External Functions
*******************************************************************************/

/*******************************************************************************
** Name:            initl
** Description:     Initialize a list.
**
** In:  p_list      pointer to a list.
** Out: None.
** Ret: None.
*******************************************************************************/
void initl(LIST_T *p_list)
{
	if( !p_list )
		return;

    p_list->origin_links.p_next = (LINKS_T *)p_list;
    p_list->origin_links.p_prev = (LINKS_T *)p_list;
    p_list->origin_links.p_origin = (LINKS_T *)p_list;   
    p_list->count = 0;
}


/*******************************************************************************
** Name:            inslt
** Description:     Insert an element to the tail of a list.
**
** In:  p_list      Pointer to a list.
**      p_element   Pointer to an element.
** Out: None.
** Ret: None.
*******************************************************************************/
void inslt(LIST_T *p_list, void *p_element)
{
	if( !p_list || !p_element )
		return;

    ((LINKS_T *)p_element)->p_origin = (LINKS_T *)p_list;
    ((LINKS_T *)p_element)->p_next = p_list->origin_links.p_prev->p_next;        
    ((LINKS_T *)p_element)->p_prev = p_list->origin_links.p_prev;                
    ((LINKS_T *)(p_list->origin_links.p_prev))->p_next = (LINKS_T *)p_element;
    p_list->origin_links.p_prev  = (LINKS_T *)p_element;
    p_list->count++;
}

/*******************************************************************************
** Name:            inslh
** Description:     Insert an element to the head of a list.
**
** In:  p_list      Pointer to a list.
**      p_element   Pointer to an element.
** Out: None.
** Ret: None.
*******************************************************************************/
void inslh(LIST_T *p_list, void *p_element)
{
	if( !p_list || !p_element )
		return;

    ((LINKS_T *)p_element)->p_origin = (LINKS_T *)p_list;
    ((LINKS_T *)p_element)->p_next = p_list->origin_links.p_next;
    ((LINKS_T *)p_element)->p_prev = p_list->origin_links.p_next->p_prev;
    ((LINKS_T *)(p_list->origin_links.p_next))->p_prev = (LINKS_T *)p_element;
    p_list->origin_links.p_next = (LINKS_T *)p_element;
    p_list->count++;
}

/*******************************************************************************
** Name:            remlh
** Description:     Remove an element from the head of a list.
**
** In:  p_list      Pointer to a list.
** Out: None.
** Ret: Pointer to the removed element, if it exists.  Otherwise return 0.
*******************************************************************************/
void *remlh(LIST_T *p_list)
{
	if( !p_list )
		return 0;

    if (p_list->count)
    {
        LINKS_T *p_element = p_list->origin_links.p_next;

        /* Update the list's next pointer. */
        ((LINKS_T *)p_list)->p_next = ((LINKS_T *)p_list)->p_next->p_next;

        /* Update the previous pointer for the new head of the list. */
        ((LINKS_T *)p_list)->p_next->p_prev = (LINKS_T *)p_list;

        /* Decrement the count. */
        p_list->count--;

        /* Return a pointer to the newly removed element. */
        return p_element;
    }
    else
    {
        /* The list is empty, return a pointer to 0. */
        return 0;
    }
}

/*******************************************************************************
** Name:            reml
** Description:     Remove an element from anywhere on a list.
**
** In:  p_list      Pointer to a list.
**      p_element   Pointer to an element in that list.
** Out: None.
** Ret: None.
*******************************************************************************/
void reml(LIST_T *p_list, void *p_element)
{
	if( !p_list || !p_element )
		return;

    (((LINKS_T *)p_element)->p_prev)->p_next = ((LINKS_T *)p_element)->p_next; 
    (((LINKS_T *)p_element)->p_next)->p_prev = ((LINKS_T *)p_element)->p_prev; 
    p_list->count--;
}

/*******************************************************************************
** Name:            inslb
** Description:     Insert an element before another element in the list.
**
** In:  p_list      Pointer to a list.
**      p_element   Pointer to an element in that list.
**		p_newElement	Pointer to the element to insert
** Out: None.
** Ret: None.
*******************************************************************************/
void inslb(LIST_T *p_list, void *p_element, void *p_newElement)
{
	if( !p_list || !p_element || !p_newElement )
		return;

	((LINKS_T *)p_newElement)->p_origin = (LINKS_T *)p_list;
	((LINKS_T *)p_newElement)->p_next = (LINKS_T *)p_element;
	((LINKS_T *)p_newElement)->p_prev = ((LINKS_T *)p_element)->p_prev;

	(((LINKS_T *)p_element)->p_prev)->p_next = (LINKS_T *)p_newElement;
	((LINKS_T *)p_element)->p_prev = (LINKS_T *)p_newElement;
	p_list->count++;
}