Linked list of Redis data types

Implementation of the chain table for Redis data types

The underlying implementation of the Redis list is a doubly linked list, with the source code under SRC adlist.h and adlist.c

Node data structure of linked list

    /*     * 双端链表节点     */    typedefstruct listNode {        // 前置节点        struct listNode *prev;        // 后置节点        struct listNode *next;        // 节点的值        void *value;    } listNode;

Linked list data structure

/ * Double-ended linked list structure */typedef struct List{//Table header nodeListNode *head;//Footer nodeListNode *tail;//Node value copy function    void* (*dup) (void*PTR);//Node value deallocation function    void(* Free)(void*PTR);//Node value comparison function    int(*match) (void*ptr,void*key);the number of nodes included in the// list    unsigned LongLen;}List;

The specific features of the linked list Redis

1. List key
2. Publish and subscribe
3. Slow query
4. Monitor

Time complexity of some functions

//Returns the number of nodes included in the given list//T = O (1)#define LISTLENGTH (L) ((l)->len)//Returns the table header node for the given list//T = O (1)#define LISTFIRST (L) ((l)->head)//Returns the footer node of the given list//T = O (1)#define LISTLAST (L) ((l)->tail)//Returns the predecessor node of a given node//T = O (1)#define LISTPREVNODE (n) ((n)->prev)//Returns the backend node of a given node//T = O (1)#define LISTNEXTNODE (n) ((n)->next)//Returns the value of the given node//T = O (1)#define LISTNODEVALUE (n) ((n)->value)//Set the value copy function of the linked list L to M//T = O (1)#define LISTSETDUPMETHOD (L,m) ((l)->dup = (m))//Set the value release function of the linked list L to M//T = O (1)#define LISTSETFREEMETHOD (L,m) ((l)->free = (m))//Set the comparison function of the list to M//T = O (1)#define LISTSETMATCHMETHOD (L,m) ((l)->match = (m))//Returns the value of the given list copy function//T = O (1)#define LISTGETDUPMETHOD (L) ((l)->dup)//Returns the value deallocation function for a given list//T = O (1)#define LISTGETFREE (L) ((l)->free)//Returns the value comparison function for a given list//T = O (1)#define LISTGETMATCHMETHOD (L) ((l)->match)

/ * * Create a new linked list * * Create a successful return list, Failure returns NULL. * * T = O (1) */List *Listcreate (void) {structList *List;//Allocate memory    if((List =Zmalloc (sizeof (*List)))== NULL)return NULL;//Initialize Properties    List -Head= List -Tail= NULL;List -Len= 0;List -Dup= NULL;List -Free= NULL;List -Match = NULL;return List;}

Note that the allocation of the malloc function here is self-fulfilling zmalloc

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Linked list of Redis data types