redis深度学习

电玩女神 2022-08-29 09:57 137阅读 0赞

# 1、redis在Linux上的安装 #

github地址：

**[https://github.com/redis/redis/releases][https_github.com_redis_redis_releases]**

**下载后，解压：**

**redis-6.2.5.tar.gz**

tar -zxvf redis-6.2.5.tar.gz

然后：

cd redis-6.2.5

make
    
    
    make install

完成后，

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d0bDE5OTI_size_16_color_FFFFFF_t_70][]

#  2、修改配置文件 #

vim redis.conf：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d0bDE5OTI_size_16_color_FFFFFF_t_70 1][]

#  3、启动redis-server #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d0bDE5OTI_size_16_color_FFFFFF_t_70 2][]

redis-server /mine/redis-6.2.5/redis.conf

#  4、连接redis #

redis-cli -p 6379

![20210801185244673.png][]

![20210801191729355.png][]

# 5、关闭redis #

![20210801191802665.png][]

![20210801191844484.png][]

# 6、测试性能 #

测试工具：

**redis-benchmark**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d0bDE5OTI_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d0bDE5OTI_size_16_color_FFFFFF_t_70 4][]

#  7、基础知识 #

### 默认的数据库有16个： ###

![20210801195727323.png][]

FLUSHDB：清空当前数据库

FLUSHALL：清空所有数据库

DBSIZE：查看当前数据库的大小

EXISTS：判断key是否存在

MOVE：移除key

EXPIRE：设置key的过期时间

TTL：查看当前key的ttl

[root@wtl199201180271 redis-6.2.5]# redis-cli -p 6379
    127.0.0.1:6379> select 3
    OK
    127.0.0.1:6379[3]> set name wxj
    OK
    127.0.0.1:6379[3]> get name
    "wxj"
    127.0.0.1:6379[3]> select 0
    OK
    127.0.0.1:6379> set name wtl
    OK
    127.0.0.1:6379> get name
    "wtl"
    127.0.0.1:6379> FLUSHDB
    OK
    127.0.0.1:6379> keys *
    (empty array)
    127.0.0.1:6379> select 3
    OK
    127.0.0.1:6379[3]> get name
    "wxj"
    127.0.0.1:6379[3]> select 0
    OK
    127.0.0.1:6379> FLUSHALL
    OK
    127.0.0.1:6379> select 3
    OK
    127.0.0.1:6379[3]> keys *
    (empty array)
    127.0.0.1:6379> DBSIZE
    (integer) 1
    127.0.0.1:6379> EXISTS name
    (integer) 1
    127.0.0.1:6379> MOVE name 1
    (integer) 0
    127.0.0.1:6379> set name wtl
    OK
    127.0.0.1:6379> MOVE name 1
    (integer) 0
    127.0.0.1:6379> EXPIRE name 10
    (integer) 1
    127.0.0.1:6379> ttl name
    (integer) 5
    127.0.0.1:6379> ttl name
    (integer) 3
    127.0.0.1:6379> ttl name
    (integer) 2
    127.0.0.1:6379> ttl name
    (integer) 1
    127.0.0.1:6379> ttl name
    (integer) 0
    127.0.0.1:6379> ttl name
    (integer) -2
    127.0.0.1:6379> ttl name
    (integer) -2

# 8、Redis为什么这么快 #

1、完全基于内存，绝大部分请求是纯粹的内存操作，非常快速。数据存在内存中，类似于HashMap，HashMap的优势就是查找和操作的时间复杂度都是O(1)；

2、数据结构简单，对数据操作也简单，Redis中的数据结构是专门进行设计的；

3、采用单线程，避免了不必要的上下文切换和竞争条件，也不存在多进程或者多线程导致的切换而消耗 CPU，不用去考虑各种锁的问题，不存在加锁释放锁操作，没有因为可能出现死锁而导致的性能消耗；

4、使用多路I/O复用模型，非阻塞IO；

5、使用底层模型不同，它们之间底层实现方式以及与客户端之间通信的应用协议不一样，Redis直接自己构建了VM 机制 ，因为一般的系统调用系统函数的话，会浪费一定的时间去移动和请求；

# 9、数据类型 #

### 9.1、String ###

APPEND：字符串追加，如果该key不存在，则创建key

127.0.0.1:6379> APPEND name "hello"
    (integer) 5
    127.0.0.1:6379> get name
    "hello"
    127.0.0.1:6379> APPEND name "world"
    (integer) 10
    127.0.0.1:6379> get name
    "helloworld"

STRLEN：获取字符串（key）的长度

127.0.0.1:6379> STRLEN name
    (integer) 10

INCR：将值加1

127.0.0.1:6379> set views 0
    OK
    127.0.0.1:6379> INCR views
    (integer) 1
    127.0.0.1:6379> INCR views
    (integer) 2
    127.0.0.1:6379> get views
    "2"

DECR：将值减1

127.0.0.1:6379> DECR views
    (integer) 1
    127.0.0.1:6379> DECR views
    (integer) 0
    127.0.0.1:6379> DECR views
    (integer) -1
    127.0.0.1:6379> DECR views
    (integer) -2
    127.0.0.1:6379> get views
    "-2"

INCRBY：i+=

DECRBY：-=

127.0.0.1:6379> INCRBY views 10
    (integer) 18
    127.0.0.1:6379> DECRBY views 20
    (integer) -2

GETRANGE：类似于Java的subString()

127.0.0.1:6379> set key1 "hello,wtl"
    OK
    127.0.0.1:6379> get key1
    "hello,wtl"
    127.0.0.1:6379> GETRANGE key1 0 3
    "hell"
    127.0.0.1:6379> GETRANGE key1 0 -1
    "hello,wtl"

TYPE：查看key的类型

127.0.0.1:6379> type name
    string

### 9.2、List ###

所有的list类型的操作都以L或者R开头！！！

**list本身是链表！！！**

LPUSH：左插入

RPUSH：右插入

LRANGE：获取指定范围的值

LPOP：左弹出一个值

RPOP：右弹出一个值

LLEN：获取list类型数据的长度

LREM：移除指定的元素（可以指定移除的个数）

127.0.0.1:6379> LPUSH mylist one
    (integer) 1
    127.0.0.1:6379> LPUSH mylist two
    (integer) 2
    127.0.0.1:6379> LPUSH mylist three
    (integer) 3
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "one"
    127.0.0.1:6379> LRANGE mylist 0 1
    1) "three"
    2) "two"
    127.0.0.1:6379> RPUSH mylist four
    (integer) 4
    127.0.0.1:6379> RPUSH mylist five
    (integer) 5
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "one"
    4) "four"
    5) "five"
    127.0.0.1:6379> LPOP mylist
    "three"
    127.0.0.1:6379> LPOP mylist
    "two"
    127.0.0.1:6379> LPOP mylist
    "one"
    127.0.0.1:6379> RPOP mylist
    "five"
    127.0.0.1:6379> RPOP mylist
    "four"
    127.0.0.1:6379> LPUSH mylist one
    (integer) 1
    127.0.0.1:6379> LPUSH mylist two
    (integer) 2
    127.0.0.1:6379> LPUSH mylist three
    (integer) 3
    127.0.0.1:6379> LLEN mylist
    (integer) 3
    127.0.0.1:6379> LREM mylist 1 one
    (integer) 1
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    127.0.0.1:6379> LPUSH mylist two
    (integer) 3
    127.0.0.1:6379> LREM mylist 2 two
    (integer) 2
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"

LTRIM：移除指定的位置的数据

127.0.0.1:6379> LRANGE mylist  0 -1
    1) "four"
    2) "three"
    3) "two"
    4) "one"
    127.0.0.1:6379> LTRIM mylist 0 1
    OK
    127.0.0.1:6379> LRANGE mylist  0 -1
    1) "four"
    2) "three"

RPOPLPUSH：弹出右侧一元素，然后左插另一个列表中

127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "one"
    127.0.0.1:6379> RPOPLPUSH mylist myotherlist
    "one"
    127.0.0.1:6379> LRANGE myotherlist 0 -1
    1) "one"
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"

LSET：在指定位置更改值

127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "one"
    127.0.0.1:6379> lset mylist 0 item
    OK
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "item"
    2) "two"
    3) "one"

LINSERT：在某个元素的before或者after插入元素

127.0.0.1:6379> LINSERT mylist before one insertItem
    (integer) 4
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "insertItem"
    4) "one"
    127.0.0.1:6379> LINSERT mylist after one insertItem2
    (integer) 5
    127.0.0.1:6379> LRANGE mylist 0 -1
    1) "three"
    2) "two"
    3) "insertItem"
    4) "one"
    5) "insertItem2"

### 9.3、Set ###

set是无序不重复集合！！！命令都以S开头！！！

SADD：添加set集合元素

SMEMBERS：查询set集合的所有元素

127.0.0.1:6379> sadd myset hello
    (integer) 1
    127.0.0.1:6379> SMEMBERS myset
    1) "hello"
    127.0.0.1:6379> sadd myset love
    (integer) 1
    127.0.0.1:6379> sadd myset wtl
    (integer) 1
    127.0.0.1:6379> SMEMBERS myset
    1) "love"
    2) "wtl"
    3) "hello"

SCARD：获取set集合元素的个数

SREM：移除指定元素

127.0.0.1:6379> SCARD myset
    (integer) 3
    127.0.0.1:6379> SMEMBERS myset
    1) "love"
    2) "wtl"
    3) "hello"
    127.0.0.1:6379> SREM myset love
    (integer) 1
    127.0.0.1:6379> SMEMBERS myset
    1) "wtl"
    2) "hello"

set集合间的交集、差集、并集：

SDIFF：差集（左差）

SINTER：交集

SUNION：并集

127.0.0.1:6379> SMEMBERS myset1
    1) "b"
    2) "c"
    3) "a"
    127.0.0.1:6379> SMEMBERS myset2
    1) "d"
    2) "c"
    3) "e"
    127.0.0.1:6379> SDIFF myset1 myset2
    1) "b"
    2) "a"
    127.0.0.1:6379> SDIFF myset2 myset1
    1) "d"
    2) "e"
    127.0.0.1:6379> SINTER myset1 myset2
    1) "c"
    127.0.0.1:6379> SUNION myset1 myset2
    1) "c"
    2) "a"
    3) "b"
    4) "d"
    5) "e"

### 9.4、Hash ###

hash实际上是hashmap，即key-> Map<String,Object>！！！

HSET：设置map键值

HGET：获取map个值根据键

HGETALL：获取map集合所有的键值

127.0.0.1:6379> HSET mymap name wtl
    (integer) 1
    127.0.0.1:6379> HSET mymap age 29
    (integer) 1
    127.0.0.1:6379> HSET mymap sex true
    (integer) 1
    127.0.0.1:6379> HGETALL mymap
    1) "name"
    2) "wtl"
    3) "age"
    4) "29"
    5) "sex"
    6) "true"
    127.0.0.1:6379> HGET mymap name
    "wtl"
    127.0.0.1:6379> HGET mymap age
    "29"
    127.0.0.1:6379> HGET mymap sex
    "true"

HMGET：获取map的多个key对应的values

HMSET：设置map的多个键值

127.0.0.1:6379> HMGET mymap name age
    1) "wtl"
    2) "29"
    127.0.0.1:6379> HMSET mymap field1 value1 field2 value2
    OK
    127.0.0.1:6379> HGETALL mymap
     1) "name"
     2) "wtl"
     3) "age"
     4) "29"
     5) "sex"
     6) "true"
     7) "field1"
     8) "value1"
     9) "field2"
    10) "value2"

HDEL：删除map里其中的k，v

HLEN：获取map里的长度

127.0.0.1:6379> HDEL mymap field1
    (integer) 1
    127.0.0.1:6379> HGETALL mymap
    '1) "name"
    2) "wtl"
    3) "age"
    4) "29"
    5) "sex"
    6) "true"
    7) "field2"
    8) "value2"
    127.0.0.1:6379> HLEN mymap
    (integer) 4

HEXISTS：判断map里的键值是否存在

HKEYS：只获取map所有的keys

HVALS：只获取map所有的values

127.0.0.1:6379> HEXISTS mymap field2 
    (integer) 1
    127.0.0.1:6379> HEXISTS mymap field1
    (integer) 0
    127.0.0.1:6379> HKEYS mymap
    1) "name"
    2) "age"
    3) "sex"
    4) "field2"
    127.0.0.1:6379> Hvals mymap
    1) "wtl"
    2) "29"
    3) "true"
    4) "value2"
    127.0.0.1:6379> HVALS mymap
    1) "wtl"
    2) "29"
    3) "true"
    4) "value2"

[https_github.com_redis_redis_releases]: https://github.com/redis/redis/releases
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[20210801185244673.png]: /images/20220829/7a77c4e0f96b4183b2f9d732f49c205f.png
[20210801191729355.png]: /images/20220829/bee640894ce94152b98e8a1f04bde751.png
[20210801191802665.png]: /images/20220829/06c91394fdb64c07a775c66f783878e9.png
[20210801191844484.png]: /images/20220829/4640ef0c0d7d45aeb115b926a9971040.png
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[20210801195727323.png]: /images/20220829/aaebb083da80497ea3f22e018b22231f.png