Redis source reading-adlist doubly linked list

Redis Source Reading-List part-

Linked list data structure in Adlist.h adlist.c

The Redis list is a doubly linked list, and an iterator is defined internally.

The functions of a doubly linked list are mainly linked list creation, deletion, node insertion, head insertion, tail insertion, nth node, node iteration traversal, linked list replication, linked list rotate, node deletion

typedefstructListNode {structListNode *prev; structListNode *Next; void*value;//defined as void * types, allowing users to use their own data structures on their own} listnode;typedefstructListiter {ListNode*Next; intdirection;} Listiter;typedefstructList {ListNode*Head; ListNode*tail; void* (*dup) (void*PTR);//when copying a linked list, the node copy function    void(* Free)(void*PTR);//Node Release function    int(*match) (void*ptr,void*key);//function to compare node value equalityUnsignedLongLen;} list;/*Functions implemented as macros*/#defineListlength (L) ((l)->len)#defineListfirst (L) ((l)->head)#defineListlast (L) ((l)->tail)#defineListprevnode (n) ((n)->prev)#defineListnextnode (n) ((n)->next)#defineListnodevalue (n) ((n)->value)#defineListsetdupmethod (L,m) ((l)->dup = (m))#defineListsetfreemethod (L,m) ((l)->free = (m))#defineListsetmatchmethod (L,m) ((l)->match = (m))#defineListgetdupmethod (L) ((l)->dup)#defineListgetfree (L) ((l)->free)#defineListgetmatchmethod (L) ((l)->match)/*prototypes*//*Create a linked list*/List*listcreate (void);/*release linked list*/voidListrelease (List *list);/*adding nodes to the head*/List*listaddnodehead (List *list,void*value);/*Add a node at the tail*/List*listaddnodetail (List *list,void*value);/*Insert a node that is value before or after the Old_node*/List*listinsertnode (list *list, ListNode *old_node,void*value,intAfter );/*Insert a node that is value before or after the Old_node*/voidListdelnode (list *list, ListNode *node);/*Create a list iterator that direction represents the direction of the iterator, forward or backward*/Listiter*listgetiterator (List *list,intdirection);/*the iterator moves to the next*/ListNode*listnext (Listiter *iter);/*releasing a list iterator*/voidListreleaseiterator (Listiter *iter);/*copy linked list, return the linked list after replication*/List*listdup (List *orig);/*look for a node with a value of key, and if the match function is defined, use the match function to compare if the key is equal*/ListNode*listsearchkey (List *list,void*key);/*returns the index node of the linked list, with index starting from 0*/ListNode*listindex (List *list,Longindex);/*List iterator reset, point to head node*/voidListrewind (list *list, Listiter *Li);/*List iterator reset, point to tail node*/voidListrewindtail (list *list, Listiter *Li);/*The last node of the list is moved to the front, rotate*/voidListrotate (List *list);/*Directions for Iterators*//*iterator direction: backwards or forwards*/#defineAl_start_head 0#defineAl_start_tail 1

Redis source reading-adlist doubly linked list