OK so I just moved the declaration of the map to the package itself which
makes it universal...all working as expected. Thanks.
On Saturday, September 12, 2020 at 1:35:49 PM UTC+1 Andy Hall wrote:
> So this works fine...
>
> func handleConnection(c net.Conn) {
> // get user details
> username := createUser(c, "Please enter you username (new users will be
> created / existing users will be loaded): ")
> // map username to connection
> var m = make(map[string]net.Conn)
> m[username] = c
> n := len(m)
> fmt.Println(strconv.Itoa(n))
>
> But due to the concurrent nature of the function ( I can't have player 1
> blocking player 2 ) the map only ever has details of your own
> connection...as seen from the output of len on the server...
>
> $ go run game-server.go 6666
> 1
> 1
>
> I guess I need to handle this outside of a goroutine...
> On Saturday, September 12, 2020 at 7:55:34 AM UTC+1 Andy Hall wrote:
>
>> I think this is exactly what I need to do...thanks very much. I'm looking
>> forward to implementing it.
>>
>> On Saturday, September 12, 2020 at 5:43:09 AM UTC+1 Shulhan wrote:
>>
>>>
>>>
>>> Pada tanggal Sab, 12 Sep 2020 02.54, Andy Hall <andyjo...@gmail.com>
>>> menulis:
>>>
>>>> if I have multiple clients connected to a tcp server and I wish to
>>>> write back to specific connections I can record the net.Conn value and
>>>> then
>>>> use the Write method on it...but when using Println I get the following
>>>> for
>>>> two clients...
>>>>
>>>> &{{0xc000094000}}
>>>> &{{0xc000094080}}
>>>>
>>>> which when testing with a simple write doesn't work...
>>>>
>>>> package main
>>>> import "net"
>>>> var c net.Conn = "&{{0xc000094000}}"
>>>> func writeConn(c net.Conn) {
>>>> c.Write([]byte(string("Hello\n")))
>>>> }
>>>> func main() {
>>>> writeConn(c)
>>>> }
>>>>
>>>> ...and results in the following...
>>>>
>>>> cannot use "&{{0xc000094000}}" (type string) as type net.Conn in
>>>> assignment
>>>>
>>>> clearly using Println to output the net.Conn is not a viable var to use
>>>> so how could I do this ? I intend to record each users net.Conn in a
>>>> database which can then be queried as required.
>>>>
>>>> any help would be most greatly appreciated.
>>>>
>>>
>>>
>>> Either I miss something or Go has different socket concept, but last
>>> time I learn this is not how the network socket works in general.
>>>
>>> First, &{{0xc000094000}} is the address of a variable. You can't
>>> convert an address from string back to variable, because that would be
>>> security issue. Usually socket connection is signed integer, in C you can
>>> assign integer value to variable let other process write into it. But in
>>> Go, connection is an interface/structure.
>>>
>>> If you want to record each users, you have two options:
>>>
>>> 1) Let the user send unique ID (for example their user ID or email or
>>> username) on first accept.
>>>
>>> 2) Get unique ID from connection IP address (beware that two or more
>>> connection may come from the same IP address).
>>>
>>> You then must have a map that store unique ID as key and net.Conn as
>>> value. So, if you want to send some value to specific user, you query the
>>> map first and if exist then you can proceeds.
>>>
>>> I hope that helps.
>>>
>>>>
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