1 struct <-> bytes

type MyStruct struct {
    a int
    b int
}
func main() {
    var ms = &MyStruct{a: 1, b: 2}
    // struct 转 byte[]
    bytes := StructToBytes(ms)
    fmt.Printf("%#v\n", bytes)
    // byte[] 转 struct
    ms2 := (*MyStruct)(BytesToStruct(bytes))
    fmt.Printf("%#v", ms2)
}
func StructToBytes(obj interface{}) []byte {
    var x reflect.SliceHeader
    length := binary.Size(obj)
    x.Len = length
    x.Cap = length
    x.Data = reflect.ValueOf(obj).Pointer()
    return *(*[]byte)(unsafe.Pointer(&x))
}
func BytesToStruct(buf []byte) unsafe.Pointer {
    return unsafe.Pointer(
        (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data,
    )
}

// a_test.go
package haha
import (
    "fmt"
    "reflect"
    "sync"
    "sync/atomic"
    "testing"
    "time"
    "unsafe"
)
func TestFloat(t *testing.T) {
    i := 10
    f := *(*float64)(unsafe.Pointer(&i))
    fmt.Println(f, reflect.TypeOf(f))
}
type MyInt int
func TestConvert(t *testing.T) {
    a := []int{1, 2, 3, 4}
    b := *(*[]MyInt)(unsafe.Pointer(&a))
    fmt.Println(b) // [1 2 3 4]
}
func TestAtomic(t *testing.T) {
    var shareBufPtr unsafe.Pointer
    writeDataFn := func() {
        data := []int{}
        for i := 0; i < 100; i++ {
            data = append(data, i)
        }
        // 使shareBufPtr指向data
        atomic.StorePointer(&shareBufPtr, unsafe.Pointer(&data))
    }
    readDataFn := func() {
        data := atomic.LoadPointer(&shareBufPtr)
        fmt.Println(data, *(*[]int)(data))
    }
    var wg sync.WaitGroup
    writeDataFn()
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func() {
            for i := 0; i < 10; i++ {
                writeDataFn()
                time.Sleep(time.Microsecond * 100) // 100us
            }
            wg.Done()
        }()
        wg.Add(1)
        go func() {
            for i := 0; i < 10; i++ {
                readDataFn()
                time.Sleep(time.Microsecond * 100) // 100us
            }
            wg.Done()
        }()
    }
    wg.Wait()
}