Redis The core object -redisObject

stay Redis It's called a core object redisObject, It's used to mean all of key and value Of , use redisObject Structure to represent String、Hash、List、Set、Zset Five types of data

redisObject The source code of is redis.sh in , Use C Language writing

• data type （type）
• Encoding mode （encoding）
• Data pointer （ptr）
• Virtual memory （vm）
• Other information

Redis data type

String（ character string ） type

String yes Redis Basic data types , There are three ways to store its data structure int、raw、embstr, It can not only store strings , You can also store integers 、 Floating point numbers 、 Even binary data , such as jpg Images or serialized objects （ One String Maximum storage 512M）

Common commands ：

mset key1 value1 key2 value2 key3 value3： Set multiple key value pairs at the same time

mset k1 name k2 age k3 gender

mget key1 key2 key3： Get the values of multiple keys at the same time

mget k1 k2 k3

append key value： Additional data

append k1 zhangsan

-->"namezhangsan"

getrange key m n : Intercept key Value of a certain segment of , From m-1 A to n-1 position

getrange k1 2 4

strlen key： obtain key Length of value

incr key： Self increasing （ Increasing , The default on the 1, Only if the string is an integer ）

decr key： Self reduction （ Decline , Default self reduction 1, Only if the string is an integer ）

set k1 2incr k1 --> 3decr k1 --> 2

incrby key 2： Custom Auto increment

decrby key 2： Customize how much to subtract

Hash（ Hash ） type

Hash（ Hash ） Type is from redis-2.0 The data structure comes after the version , Used to store the mapping between strings and strings .Hash There are two ways to implement objects , Namely Ziplist and hashtable, among hashtable Storage mode Key yes String type , value Also with key-value Storage in the form of .

Common commands ：

hmset key field value [field value ...]： Batch settings hash key A batch of field value

127.0.0.1:6379> hmset user1 name tan age 18 sex maleOK

hget key field : Get one value value

127.0.0.1:6379> hget user1 name"tan"

hmget key field1 field2 ... fieldN: Batch acquisition hash key A batch of field Corresponding value

127.0.0.1:6379> hmget user1 name sex1) "li"2) "male"

hgetall key : Get all the key value pairs

127.0.0.1:6379> hgetall user11) "name"2) "tan"3) "age"4) "18"5) "sex"6) "male"

hset key field value: Set up hash key Corresponding field Of value

127.0.0.1:6379> hset user1 name li(integer) 0127.0.0.1:6379> hget user1 name"li"

hdel key field: Delete hash key Corresponding field Of value

127.0.0.1:6379> hdel user1 sex(integer) 1127.0.0.1:6379> hgetall user11) "name"2) "li"3) "age"4) "19"

hlen key: obtain hash key field The number of

127.0.0.1:6379> hlen user1(integer) 3

hincrby key field increment: hash key Corresponding field Of value Self increasing

127.0.0.1:6379> hincrby user1 age 1(integer) 19127.0.0.1:6379> hincrby user1 age -1(integer) 18127.0.0.1:6379> hincrby user1 age -2(integer) 16127.0.0.1:6379> hincrby user1 age 3(integer) 19

List（ list ） type

List A type is a linked list structure , The main functions are push （ Into the stack ）、pop（ Out of the stack ）;List Type in the redis-3.2 Previous versions used ziplist and linkedlist Implemented , The later version introduced quicklist

Common commands ：

lpush: stay key Corresponding list Add string elements to the header of

lpop： from key Corresponding list The head of the delete element

rpush： stay key Corresponding list Add string elements to the end of

lrange： Show key Corresponding list The elements of

lpush key value [value ...]： stay key Corresponding list Add string elements to the header of

127.0.0.1:6379> lpush mylist 1(integer) 1127.0.0.1:6379> lpush mylist 2(integer) 2127.0.0.1:6379> lpush mylist "3"(integer) 3

lrange key start stop: Show key Corresponding list The elements of

127.0.0.1:6379> lrange mylist 0 -11) "3"2) "2"3) "1"

rpush key value [value ...]: stay key Corresponding list Add string elements to the end of

127.0.0.1:6379> rpush mylist 4(integer) 4127.0.0.1:6379> lrange mylist 0 -11) "3"2) "2"3) "1"4) "4"

lindex key index： Print key Corresponding list The first index The element of bit

127.0.0.1:6379> lindex mylist 0"3"

lset key index value： modify key Corresponding list The first index The element of bit

127.0.0.1:6379> lset mylist 0 111OK127.0.0.1:6379> lrange mylist 0 -11) "111"2) "2"3) "1"4) "4"

lpop key: from key Corresponding list The head of the delete element

127.0.0.1:6379> lpop mylist"111"127.0.0.1:6379> lrange mylist 0 -11) "2"2) "1"3) "4"

rpop key: from key Corresponding list The tail of the delete element

127.0.0.1:6379> rpop mylist"4"127.0.0.1:6379> lrange mylist 0 -11) "2"2) "1"

llen key： Print key Corresponding list The length of

127.0.0.1:6379> llen mylist(integer) 2

lrem key count value: from key Corresponding list Delete an element count On behalf of the number one ,count be equal to 0 On behalf of all

127.0.0.1:6379> lrange mylist 0 -11) "3"2) "2"3) "1"127.0.0.1:6379> lrem mylist 0 3(integer) 1127.0.0.1:6379> lrange mylist 0 -11) "2"2) "1"

linsert key BEFORE|AFTER pivot value: from key Corresponding list Insert an element

127.0.0.1:6379> lrange mylist 0 -11) "10"2) "5"3) "2"4) "1"127.0.0.1:6379> linsert mylist before 10 99(integer) 5127.0.0.1:6379> lrange mylist 0 -11) "99"2) "10"3) "5"4) "2"5) "1"127.0.0.1:6379> linsert mylist after 2 999(integer) 6127.0.0.1:637.........