redis的list类型,可以存储双向链表作为value,key保留有head和tail指针可以指向双向链表的头和尾,因此可以直接从头或尾对list进行操作。
全部命令如下:
127.0.0.1:6379> help @listBLMOVE source destination LEFT|RIGHT LEFT|RIGHT timeoutsummary: Pop an element from a list, push it to another list and return it; or block until one is availablesince: 6.2.0BLMPOP timeout numkeys key [key ...] LEFT|RIGHT [COUNT count]summary: Pop elements from a list, or block until one is availablesince: 7.0.0BLPOP key [key ...] timeoutsummary: Remove and get the first element in a list, or block until one is availablesince: 2.0.0BRPOP key [key ...] timeoutsummary: Remove and get the last element in a list, or block until one is availablesince: 2.0.0BRPOPLPUSH source destination timeoutsummary: Pop an element from a list, push it to another list and return it; or block until one is availablesince: 2.2.0LINDEX key indexsummary: Get an element from a list by its indexsince: 1.0.0LINSERT key BEFORE|AFTER pivot elementsummary: Insert an element before or after another element in a listsince: 2.2.0LLEN keysummary: Get the length of a listsince: 1.0.0LMOVE source destination LEFT|RIGHT LEFT|RIGHTsummary: Pop an element from a list, push it to another list and return itsince: 6.2.0LMPOP numkeys key [key ...] LEFT|RIGHT [COUNT count]summary: Pop elements from a listsince: 7.0.0LPOP key [count]summary: Remove and get the first elements in a listsince: 1.0.0LPOS key element [RANK rank] [COUNT num-matches] [MAXLEN len]summary: Return the index of matching elements on a listsince: 6.0.6LPUSH key element [element ...]summary: Prepend one or multiple elements to a listsince: 1.0.0LPUSHX key element [element ...]summary: Prepend an element to a list, only if the list existssince: 2.2.0LRANGE key start stopsummary: Get a range of elements from a listsince: 1.0.0LREM key count elementsummary: Remove elements from a listsince: 1.0.0LSET key index elementsummary: Set the value of an element in a list by its indexsince: 1.0.0LTRIM key start stopsummary: Trim a list to the specified rangesince: 1.0.0RPOP key [count]summary: Remove and get the last elements in a listsince: 1.0.0RPOPLPUSH source destinationsummary: Remove the last element in a list, prepend it to another list and return itsince: 1.2.0RPUSH key element [element ...]summary: Append one or multiple elements to a listsince: 1.0.0RPUSHX key element [element ...]summary: Append an element to a list, only if the list existssince: 2.2.0
下面示例如下:
lpush:lpush key e1 e2 e3…将数据从头那里推入list
lpop:lpop key,将数据从head弹出
这样2个同向的命令组合起来,可以实现一个队列
。
反向的命令组合起来,可以实现一个栈。
127.0.0.1:6379> lpush k1 a b c d e
(integer) 5
127.0.0.1:6379> lpop k1
"e"
127.0.0.1:6379> lpop k1
"d"
lrange :lrange key start end,展示key对应的从下标start到end的所有数据
127.0.0.1:6379> lrange k1 0 -1
1) "c"
2) "b"
3) "a"
lindex:lindex key index ,返回key对应的List指定index位置的值
127.0.0.1:6379> lrange k1 0 -1
1) "f"
2) "e"
3) "d"
4) "c"
5) "b"
6) "a"
127.0.0.1:6379> lindex k1 1
"e"
lset:lset key index value,在key对应的list中的指定下标处替换为value
127.0.0.1:6379> lset k1 3 x
OK
127.0.0.1:6379> lrange k1 0 -1
1) "f"
2) "e"
3) "d"
4) "x"
5) "b"
6) "a"
lrem:lrem key num target,删除key对应的list中的target元素,如果num大于0,从head开始删num个。如果num小于0,从tail开始删abs(num)个
127.0.0.1:6379> lrange k3 0 -11) "d"2) "6"3) "a"4) "5"5) "c"6) "4"7) "a"8) "3"9) "b"
10) "2"
11) "a"
12) "1"
127.0.0.1:6379> lrem k3 2 a
(integer) 2
127.0.0.1:6379> lrange k3 0 -11) "d"2) "6"3) "5"4) "c"5) "4"6) "3"7) "b"8) "2"9) "a"
10) "1"
linsert:linsert key before/after element value,在key对应的list中,在元素element(不是下标)之前或者之后,添加value
127.0.0.1:6379> lrange k3 0 -11) "d"2) "6"3) "5"4) "c"5) "4"6) "3"7) "b"8) "2"9) "a"
10) "1"
127.0.0.1:6379> linsert k3 after 6 a
(integer) 11
127.0.0.1:6379> lrange k3 0 -11) "d"2) "6"3) "a"4) "5"5) "c"6) "4"7) "3"8) "b"9) "2"
10) "a"
11) "1"
llen:llen key,返回长度
redis的List类型有很多关于下标的操作,也可以将其抽象为一个数组来使用
。
127.0.0.1:6379> llen k3
(integer) 10
blpop:blpop key time,弹出指定key对应的list中的一个元素,如果list没有元素或者不存在key对应的这个list,则阻塞等待time指定的时间,0表示一直等待,单位是s。
127.0.0.1:6379> blpop k1 0
阻塞期间如果list有了元素,则会中断阻塞并弹出
127.0.0.1:6379> blpop k1 0
1) "k1"
2) "a"
(35.77s)
ltrim:ltrim key start end,删除key对应的list start和end之外的两端的元素
127.0.0.1:6379> lrange k4 0 -1
1) "f"
2) "e"
3) "d"
4) "c"
5) "b"
6) "a"
127.0.0.1:6379> ltrim k4 1 -2
OK
127.0.0.1:6379> lrange k4 0 -1
1) "e"
2) "d"
3) "c"
4) "b"