buffer.c

嵌入式操作链表的模版,有注释和说明 对需要解决数据链表的朋友可以参考

/********************************************************************************/
/* filename: buffer.c                                                           */
/* created : hw-chen                                                            */
/********************************************************************************/
#include "com_inc.h"

st_buffer_node   buffer_node[MAX_BUFF];
st_buffer_list   free_buffer_list;

/********************************************************************************/
/* function : buffer_list_initialize()                                          */
/* created  : hw-chen                                                           */
/* descript : initialize the free buffer list                                   */
/********************************************************************************/
void buffer_list_initialize(void)
{   int i=0x0;
    free_buffer_list.head=null;
    free_buffer_list.tail=null;
    while(i<MAX_BUFF)
    {   list_add_tail(&free_buffer_list,&buffer_node[i++]);
    }
}

/********************************************************************************/
/* function : get_node_from_pool()                                              */
/* created  : hw-chen                                                           */
/* descript : 从POOL里面取出一个节点                                            */
/********************************************************************************/
st_buffer_node * get_node_from_pool(void)
{   return list_del_head(&free_buffer_list);
}

/********************************************************************************/
/* function : set_node_to_pool()                                                */
/* created  : hw-chen                                                           */
/* descript : 把一个自由节点放回到POOL里面                                      */
/********************************************************************************/
void set_node_to_pool(st_buffer_node * node)
{   list_add_tail(&free_buffer_list,node);
}


/********************************************************************************/
/* function : list_add_tail()                                                   */
/* created  : hw-chen                                                           */
/* descript : Add a new entry after the specified list's tail but it is must    */
/*            less max                                                          */
/********************************************************************************/
void list_add_tail(st_buffer_list * list, st_buffer_node * node)
{   if( list->tail==null)
    {   list->head=node;
        list->tail=node;
        node->prev=null;
        node->next=null;
    }
    else
    {   list->tail->next=node;
        node->prev=list->tail;
        node->next=null;
        list->tail=node;
    }
}
/********************************************************************************/
/* function : list_add_head()                                                   */
/* created  : hw-chen                                                           */
/* descript : Add a new entry after the specified list's tail but it is must    */
/*            less max                                                          */
/********************************************************************************/
void list_add_head(st_buffer_list * list, st_buffer_node * node)
{   if( list->head==null)
    {   list->head=node;
        list->tail=node;
        node->prev=null;
        node->next=null;
    }
    else
    {   list->head->prev=node;
        node->next=list->head;
        node->prev=null;
        list->head=node;
    }
}
/********************************************************************************/
/* function : list_add_between()                                                */
/* created  : hw-chen                                                           */
/* descript : Add a new entry after the specified list's tail but it is must    */
/*            less max                                                          */
/********************************************************************************/
void list_add_between(st_buffer_node * prev, st_buffer_node * next, st_buffer_node * node)
{   prev->next=node;
    node->prev=prev;
    node->next=next;
    next->prev=node;
}

/********************************************************************************/
/* function : list_del_head()                                                   */
/* created  : hw-chen                                                           */
/* descript : remove entry from the specified list's head .                     */
/********************************************************************************/
st_buffer_node * list_del_head(st_buffer_list * list)
{   st_buffer_node * head;
    head=list->head;
    if( list->head==null)
    {   return null;
    }
    if( list->head==list->tail)
    {   list->head=null;
        list->tail=null;
        return head;
    }
    else
    {   list->head=head->next;
        list->head->prev=null;
        return head;
    }
}

/********************************************************************************/
/* function : list_get_buffer()                                                 */
/* created  : hw-chen                                                           */
/* descript : get and remove entry from the specified list's head .             */
/********************************************************************************/
st_buffer_node * list_get_buffer(st_buffer_list * list)
{   return list_del_head(list);
}

/********************************************************************************/
/* function : list_search_sequence()                                            */
/* created  : hw-chen                                                           */
/* descript : remove entry from the specified list's head .                     */
/********************************************************************************/
int list_search_sequence(st_buffer_list * list, st_buffer_node * node,st_buffer_node ** prev, st_buffer_node ** next)
{   st_buffer_node * nxt1;
    st_buffer_node * nxt2;
    nxt1=list->head;
    nxt2=nxt1->next;
    while(nxt2!=null)
    {   if((node->sequence>nxt1->sequence)&&(node->sequence<nxt2->sequence))
        {   break;
        }
        if(node->sequence<=nxt1->sequence)
        {   nxt2=null;
            break;
        }
        nxt1=nxt2;
        nxt2=nxt2->next;
    }
    if(nxt2==null)
    {   msg_addr_value(prev,null);
        msg_addr_value(next,null);
        return ERR_ERROR;
    }
    else
    {   msg_addr_value(prev,nxt1);
        msg_addr_value(next,nxt2);
        return 0x1;
    }
}

/********************************************************************************/
/* function : list_add_sequence()                                               */
/* created  : hw-chen                                                           */
/* descript : remove entry from the specified list's head .                     */
/********************************************************************************/
int list_add_sequence(st_buffer_list * list, st_buffer_node * node)
{   st_buffer_node * prev;
    st_buffer_node * next;
    if( list_search_sequence(list,node,&prev,&next)==0x1)
    {   list_add_between(prev,next,node);
        return 0x1;
    }
    else
    {   return ERR_ERROR;
    }
}