Value/list in redis

list： Acyclic bidirectional linked list

redis key There are two pointers in ,head The head pointer ,tail Tail pointer

lpush key value[value...] 

lpush k1 abcdef        ==>        fedcba

rpush key value[value...] 

rpush k1 abcdef        ==>        abcdef

lpop key

lpop k1        ==>        f        

rpop key

rpop k2        ==>        f

Stack ： Same direction command

queue ： Reverse command  

lrange key start end

lrange k1 0 -1        ==>        return k1 All elements in  

lindex k1 -1        ==>        Take out k1 The last element in

lset k1 3 y          ==>        Update the index to 3 The elements of , Change it to y

lrem k3 2 a        ==>        from k3 Remove two from a（ From left to right ）

lrem k3 -2 a       ==>        from k3 Remove two from a（ From right to left ）

linsert k3 after 6 a        ==>        stay k3 in 6 Add later a（ If there are more than one 6, In the first place 6 Add later ）

linsert k3 before 6 a     ==>        stay k3 in 6 Add a

llen k3        ==>        Statistics k3 How many elements are there in  

blpop key[key...] timeout

timeout： Blocking seconds ,timeout=0 when , It will keep blocking , Until there is data in the future  

ltrim key start end： take start end Remove the data at both ends , Does not include the number indicated , Things in the middle will not be deleted