Go deep into the underlying C source code and explain the core design principles of redis

Catalog

1.redis Basic characteristics

 2.redis Application scenarios

3. data structure

 3.1 string

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1.redis Basic characteristics

 2.redis Application scenarios

 

3. data structure

 3.1 string

redis All of them are k-v structure ,key At the bottom, it's all string structure ,value Yes string,hash,set,sorted set,list etc. .

among string The data structure in is as follows ,3.2 Previously, there were only three parameters len( Character length ),free( Free space ),buf[]( Storage variable )

redis in string Three characteristics of strings

1. Binary secure data structures

        c Language in string str='xxx\0'; The structure of string is represented by a \0 For the end .

2. Provides a memory pre allocation mechanism , Avoid frequent memory allocation

        Provide capacity expansion mechanism , Algorithm :(len+addlen)*2

3. compatible C Language function library .

 bitmap Bottom use string,string The maximum length that a string can represent 512M.

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