/**
  * @file lv_ll.c
  * Handle linked lists.
  * The nodes are dynamically allocated by the 'lv_mem' module,
  */
 
 /*********************
  *      INCLUDES
  *********************/
 #include "lv_ll.h"
 #include "lv_mem.h"
 
 /*********************
  *      DEFINES
  *********************/
 #define LL_NODE_META_SIZE (sizeof(lv_ll_node_t *) + sizeof(lv_ll_node_t *))
 #define LL_PREV_P_OFFSET(ll_p) (ll_p->n_size)
 #define LL_NEXT_P_OFFSET(ll_p) (ll_p->n_size + sizeof(lv_ll_node_t *))
 
 /**********************
  *      TYPEDEFS
  **********************/
 
 /**********************
  *  STATIC PROTOTYPES
  **********************/
 static void node_set_prev(lv_ll_t * ll_p, lv_ll_node_t * act, lv_ll_node_t * prev);
 static void node_set_next(lv_ll_t * ll_p, lv_ll_node_t * act, lv_ll_node_t * next);
 
 /**********************
  *  STATIC VARIABLES
  **********************/
 
 /**********************
  *      MACROS
  **********************/
 
 /**********************
  *   GLOBAL FUNCTIONS
  **********************/
 
 /**
  * Initialize linked list
  * @param ll_p pointer to lv_ll_t variable
  * @param node_size the size of 1 node in bytes
  */
 void _lv_ll_init(lv_ll_t * ll_p, uint32_t node_size)
 {
     ll_p->head = NULL;
     ll_p->tail = NULL;
 #ifdef LV_ARCH_64
     /*Round the size up to 8*/
     node_size = (node_size + 7) & (~0x7);
 #else
     /*Round the size up to 4*/
     node_size = (node_size + 3) & (~0x3);
 #endif
 
     ll_p->n_size = node_size;
 }
 
 /**
  * Add a new head to a linked list
  * @param ll_p pointer to linked list
  * @return pointer to the new head
  */
 void * _lv_ll_ins_head(lv_ll_t * ll_p)
 {
     lv_ll_node_t * n_new;
 
     n_new = lv_mem_alloc(ll_p->n_size + LL_NODE_META_SIZE);
 
     if(n_new != NULL) {
         node_set_prev(ll_p, n_new, NULL);       /*No prev. before the new head*/
         node_set_next(ll_p, n_new, ll_p->head); /*After new comes the old head*/
 
         if(ll_p->head != NULL) { /*If there is old head then before it goes the new*/
             node_set_prev(ll_p, ll_p->head, n_new);
         }
 
         ll_p->head = n_new;      /*Set the new head in the dsc.*/
         if(ll_p->tail == NULL) { /*If there is no tail (1. node) set the tail too*/
             ll_p->tail = n_new;
         }
     }
 
     return n_new;
 }
 
 /**
  * Insert a new node in front of the n_act node
  * @param ll_p pointer to linked list
  * @param n_act pointer a node
  * @return pointer to the new node
  */
 void * _lv_ll_ins_prev(lv_ll_t * ll_p, void * n_act)
 {
     lv_ll_node_t * n_new;
 
     if(NULL == ll_p || NULL == n_act) return NULL;
 
     if(_lv_ll_get_head(ll_p) == n_act) {
         n_new = _lv_ll_ins_head(ll_p);
         if(n_new == NULL) return NULL;
     }
     else {
         n_new = lv_mem_alloc(ll_p->n_size + LL_NODE_META_SIZE);
         if(n_new == NULL) return NULL;
 
         lv_ll_node_t * n_prev;
         n_prev = _lv_ll_get_prev(ll_p, n_act);
         node_set_next(ll_p, n_prev, n_new);
         node_set_prev(ll_p, n_new, n_prev);
         node_set_prev(ll_p, n_act, n_new);
         node_set_next(ll_p, n_new, n_act);
     }
 
     return n_new;
 }
 
 /**
  * Add a new tail to a linked list
  * @param ll_p pointer to linked list
  * @return pointer to the new tail
  */
 void * _lv_ll_ins_tail(lv_ll_t * ll_p)
 {
     lv_ll_node_t * n_new;
 
     n_new = lv_mem_alloc(ll_p->n_size + LL_NODE_META_SIZE);
 
     if(n_new != NULL) {
         node_set_next(ll_p, n_new, NULL);       /*No next after the new tail*/
         node_set_prev(ll_p, n_new, ll_p->tail); /*The prev. before new is the old tail*/
         if(ll_p->tail != NULL) {                /*If there is old tail then the new comes after it*/
             node_set_next(ll_p, ll_p->tail, n_new);
         }
 
         ll_p->tail = n_new;      /*Set the new tail in the dsc.*/
         if(ll_p->head == NULL) { /*If there is no head (1. node) set the head too*/
             ll_p->head = n_new;
         }
     }
 
     return n_new;
 }
 
 /**
  * Remove the node 'node_p' from 'll_p' linked list.
  * It does not free the memory of node.
  * @param ll_p pointer to the linked list of 'node_p'
  * @param node_p pointer to node in 'll_p' linked list
  */
 void _lv_ll_remove(lv_ll_t * ll_p, void * node_p)
 {
     if(ll_p == NULL) return;
 
     if(_lv_ll_get_head(ll_p) == node_p) {
         /*The new head will be the node after 'n_act'*/
         ll_p->head = _lv_ll_get_next(ll_p, node_p);
         if(ll_p->head == NULL) {
             ll_p->tail = NULL;
         }
         else {
             node_set_prev(ll_p, ll_p->head, NULL);
         }
     }
     else if(_lv_ll_get_tail(ll_p) == node_p) {
         /*The new tail will be the node before 'n_act'*/
         ll_p->tail = _lv_ll_get_prev(ll_p, node_p);
         if(ll_p->tail == NULL) {
             ll_p->head = NULL;
         }
         else {
             node_set_next(ll_p, ll_p->tail, NULL);
         }
     }
     else {
         lv_ll_node_t * n_prev = _lv_ll_get_prev(ll_p, node_p);
         lv_ll_node_t * n_next = _lv_ll_get_next(ll_p, node_p);
 
         node_set_next(ll_p, n_prev, n_next);
         node_set_prev(ll_p, n_next, n_prev);
     }
 }
 
 /**
  * Remove and free all elements from a linked list. The list remain valid but become empty.
  * @param ll_p pointer to linked list
  */
 void _lv_ll_clear(lv_ll_t * ll_p)
 {
     void * i;
     void * i_next;
 
     i      = _lv_ll_get_head(ll_p);
     i_next = NULL;
 
     while(i != NULL) {
         i_next = _lv_ll_get_next(ll_p, i);
 
         _lv_ll_remove(ll_p, i);
         lv_mem_free(i);
 
         i = i_next;
     }
 }
 
 /**
  * Move a node to a new linked list
  * @param ll_ori_p pointer to the original (old) linked list
  * @param ll_new_p pointer to the new linked list
  * @param node pointer to a node
  * @param head true: be the head in the new list
  *             false be the tail in the new list
  */
 void _lv_ll_chg_list(lv_ll_t * ll_ori_p, lv_ll_t * ll_new_p, void * node, bool head)
 {
     _lv_ll_remove(ll_ori_p, node);
 
     if(head) {
         /*Set node as head*/
         node_set_prev(ll_new_p, node, NULL);
         node_set_next(ll_new_p, node, ll_new_p->head);
 
         if(ll_new_p->head != NULL) { /*If there is old head then before it goes the new*/
             node_set_prev(ll_new_p, ll_new_p->head, node);
         }
 
         ll_new_p->head = node;       /*Set the new head in the dsc.*/
         if(ll_new_p->tail == NULL) { /*If there is no tail (first node) set the tail too*/
             ll_new_p->tail = node;
         }
     }
     else {
         /*Set node as tail*/
         node_set_prev(ll_new_p, node, ll_new_p->tail);
         node_set_next(ll_new_p, node, NULL);
 
         if(ll_new_p->tail != NULL) { /*If there is old tail then after it goes the new*/
             node_set_next(ll_new_p, ll_new_p->tail, node);
         }
 
         ll_new_p->tail = node;       /*Set the new tail in the dsc.*/
         if(ll_new_p->head == NULL) { /*If there is no head (first node) set the head too*/
             ll_new_p->head = node;
         }
     }
 }
 
 /**
  * Return with head node of the linked list
  * @param ll_p pointer to linked list
  * @return pointer to the head of 'll_p'
  */
 void * _lv_ll_get_head(const lv_ll_t * ll_p)
 {
     if(ll_p == NULL) return NULL;
     return ll_p->head;
 }
 
 /**
  * Return with tail node of the linked list
  * @param ll_p pointer to linked list
  * @return pointer to the tail of 'll_p'
  */
 void * _lv_ll_get_tail(const lv_ll_t * ll_p)
 {
     if(ll_p == NULL) return NULL;
     return ll_p->tail;
 }
 
 /**
  * Return with the pointer of the next node after 'n_act'
  * @param ll_p pointer to linked list
  * @param n_act pointer a node
  * @return pointer to the next node
  */
 void * _lv_ll_get_next(const lv_ll_t * ll_p, const void * n_act)
 {
     /*Pointer to the next node is stored in the end of this node.
      *Go there and return the address found there*/
     const lv_ll_node_t * n_act_d = n_act;
     n_act_d += LL_NEXT_P_OFFSET(ll_p);
     return *((lv_ll_node_t **)n_act_d);
 }
 
 /**
  * Return with the pointer of the previous node before 'n_act'
  * @param ll_p pointer to linked list
  * @param n_act pointer a node
  * @return pointer to the previous node
  */
 void * _lv_ll_get_prev(const lv_ll_t * ll_p, const void * n_act)
 {
     /*Pointer to the prev. node is stored in the end of this node.
      *Go there and return the address found there*/
     const lv_ll_node_t * n_act_d = n_act;
     n_act_d += LL_PREV_P_OFFSET(ll_p);
     return *((lv_ll_node_t **)n_act_d);
 }
 
 /**
  * Return the length of the linked list.
  * @param ll_p pointer to linked list
  * @return length of the linked list
  */
 uint32_t _lv_ll_get_len(const lv_ll_t * ll_p)
 {
     uint32_t len = 0;
     void * node;
 
     for(node = _lv_ll_get_head(ll_p); node != NULL; node = _lv_ll_get_next(ll_p, node)) {
         len++;
     }
 
     return len;
 }
 
 /**
  * Move a node before an other node in the same linked list
  * @param ll_p pointer to a linked list
  * @param n_act pointer to node to move
  * @param n_after pointer to a node which should be after `n_act`
  */
 void _lv_ll_move_before(lv_ll_t * ll_p, void * n_act, void * n_after)
 {
     if(n_act == n_after) return; /*Can't move before itself*/
 
     void * n_before;
     if(n_after != NULL)
         n_before = _lv_ll_get_prev(ll_p, n_after);
     else
         n_before = _lv_ll_get_tail(ll_p); /*if `n_after` is NULL `n_act` should be the new tail*/
 
     if(n_act == n_before) return; /*Already before `n_after`*/
 
     /*It's much easier to remove from the list and add again*/
     _lv_ll_remove(ll_p, n_act);
 
     /*Add again by setting the prev. and next nodes*/
     node_set_next(ll_p, n_before, n_act);
     node_set_prev(ll_p, n_act, n_before);
     node_set_prev(ll_p, n_after, n_act);
     node_set_next(ll_p, n_act, n_after);
 
     /*If `n_act` was moved before NULL then it become the new tail*/
     if(n_after == NULL) ll_p->tail = n_act;
 
     /*If `n_act` was moved before `NULL` then it's the new head*/
     if(n_before == NULL) ll_p->head = n_act;
 }
 
 /**
  * Check if a linked list is empty
  * @param ll_p pointer to a linked list
  * @return true: the linked list is empty; false: not empty
  */
 bool _lv_ll_is_empty(lv_ll_t * ll_p)
 {
     if(ll_p == NULL) return true;
 
     if(ll_p->head == NULL && ll_p->tail == NULL) return true;
 
     return false;
 }
 
 /**********************
  *   STATIC FUNCTIONS
  **********************/
 
 /**
  * Set the previous node pointer of a node
  * @param ll_p pointer to linked list
  * @param act pointer to a node which prev. node pointer should be set
  * @param prev pointer to a node which should be the previous node before 'act'
  */
 static void node_set_prev(lv_ll_t * ll_p, lv_ll_node_t * act, lv_ll_node_t * prev)
 {
     if(act == NULL) return; /*Can't set the prev node of `NULL`*/
 
     uint8_t * act8 = (uint8_t *)act;
 
     act8 += LL_PREV_P_OFFSET(ll_p);
 
     lv_ll_node_t ** act_node_p = (lv_ll_node_t **) act8;
     lv_ll_node_t ** prev_node_p = (lv_ll_node_t **) &prev;
 
     *act_node_p = *prev_node_p;
 }
 
 /**
  * Set the 'next node pointer' of a node
  * @param ll_p pointer to linked list
  * @param act pointer to a node which next node pointer should be set
  * @param next pointer to a node which should be the next node before 'act'
  */
 static void node_set_next(lv_ll_t * ll_p, lv_ll_node_t * act, lv_ll_node_t * next)
 {
     if(act == NULL) return; /*Can't set the next node of `NULL`*/
     uint8_t * act8 = (uint8_t *)act;
 
     act8 += LL_NEXT_P_OFFSET(ll_p);
     lv_ll_node_t ** act_node_p = (lv_ll_node_t **) act8;
     lv_ll_node_t ** next_node_p = (lv_ll_node_t **) &next;
 
     *act_node_p = *next_node_p;
 }

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