Re: [go-nuts] How to generate a positive int64 from byte slice
The 32 bytes were just a product of the hash function that we were using,
but I've simplified it by changing the hash function to one that only
generates 8 bytes.
My current solution is:
func EmailToID(email, salt string) int64 {
d := sha3.NewShake256()
d.Write([]byte(email))
d.Write([]byte(salt))
h := make([]byte, 8)
d.Read(h)
var n int64
buff := bytes.NewBuffer(h)
binary.Read(buff, binary.LittleEndian, &n)
if n < 0 {
n *= -1
}
return n
}
So, I'm actually using all 64 bits, but taking the absolute value of the
resulting int64, which in effect means that I'm only considering 63 bytes.
On Saturday, 24 September 2016 02:32:24 UTC+2, Caleb Spare wrote:
>
> You'll probably want to use encoding/binary.
>
> But which 8 of the 32 bytes are you going to use? (or really, which 63
> bits?)
>
> -Caleb
>
> On Fri, Sep 23, 2016 at 5:25 PM, JohnGB >
> wrote:
> > I have a byte slice 32 bytes long, and I would like to use it to
> generate a
> > positive int64. Is there a standard way to do this, or do I need to
> write
> > my own function (most likely using bit shifts)?
> >
> > The backstory is that I need to generate unique (low collision
> likelihood)
> > integer IDs from email addresses. However it needs to be that every
> time a
> > given email is used to generate an int64, that it generates the same
> int64.
> > I've settled on using a SHA3 hash with a salt to get a low collision
> byte
> > slice, which I then need to generate a positive int64 from.
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups
> > "golang-nuts" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an
> > email to golang-nuts...@googlegroups.com .
> > For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
Re: [go-nuts] How to generate a positive int64 from byte slice
You'll probably want to use encoding/binary. But which 8 of the 32 bytes are you going to use? (or really, which 63 bits?) -Caleb On Fri, Sep 23, 2016 at 5:25 PM, JohnGB wrote: > I have a byte slice 32 bytes long, and I would like to use it to generate a > positive int64. Is there a standard way to do this, or do I need to write > my own function (most likely using bit shifts)? > > The backstory is that I need to generate unique (low collision likelihood) > integer IDs from email addresses. However it needs to be that every time a > given email is used to generate an int64, that it generates the same int64. > I've settled on using a SHA3 hash with a salt to get a low collision byte > slice, which I then need to generate a positive int64 from. > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] How to generate a positive int64 from byte slice
I have a byte slice 32 bytes long, and I would like to use it to generate a positive int64. Is there a standard way to do this, or do I need to write my own function (most likely using bit shifts)? The backstory is that I need to generate unique (low collision likelihood) integer IDs from email addresses. However it needs to be that every time a given email is used to generate an int64, that it generates the same int64. I've settled on using a SHA3 hash with a salt to get a low collision byte slice, which I then need to generate a positive int64 from. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
