Go Memory Optimizer (i)-struct

Principle

About Golang The writing order of field in the same struct will be different for different memory allocation sizes. The main reasons are as follows: The field memory allocation within a struct is based on 4 B and must be exclusive at 4B.

Example

type A1 struct {    a bool    b uint32    c bool    d uint32    e uint8    f uint32    g uint8}

Calculate the amount of memory that A1 needs to occupy:

1. First, the 1th 4B in the a,a is a bool type, occupies 1B, the remaining 3B
2. Then look at B is UInt32, Occupy 4B, the remaining 3B, so offset to the next 4B space, then we will find 3B did not put things, was wasted
3. Down, A1 to occupy 28B of space
   According to 1, 22 steps are easy to see, there is a lot of wasted space.

Optimization:

type A2 struct {    a bool    c bool    e uint8    g uint8    b uint32    d uint32    f uint32}

1. First, the 1th 4B in the a,a is a bool type, occupies 1B, the remaining 3B
2. C is bool, take 1B, put the remaining 2B after
3. D is uint8, Occupy 1B, put the remaining 1B after
4. Turn down
   This can make memory usage much higher.