go - How to create a custom hashcode to determine if data has mutated -

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say have struct type has int64 , bools, along embedded types have more int64 , bool type fields.

type t1 struct {    f1 int64    f2 int64    f3 bool    t2 t2 }  type t2 struct {    f4 int64    f5 int64    f6 bool }

now using structs fields/properties, want generate hashcode.

the aim of can determine if contents of instance has changed comparing before/after hashcode value.

so if t1 instance has changed i.e. of own properties value of hash should different.

you can use like:

func (t *t1) hash() uint64 {     hb := make([]byte, 8+8+1+8+8+1)     binary.bigendian.putuint64(hb, uint64(t.f1))     binary.bigendian.putuint64(hb[8:], uint64(t.f2))     if t.f3 {         hb[16] = 1     }     binary.bigendian.putuint64(hb[17:], uint64(t.t2.f4))     binary.bigendian.putuint64(hb[25:], uint64(t.t2.f5))     if t.t2.f6 {         hb[33] = 1     }     f := fnv.new64a()     f.write(hb)     return f.sum64() }

playground

although if using map key, it's better directly use struct key , let go handle it.


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