On Thu, Dec 24, 2020 at 1:46 AM Robert Engels <reng...@ix.netcom.com> wrote:
> I was referring to the comments about the encoder keeping state. You can
> reset the encoder. You may need your own framing to do so - I’m not looking
> at the gob streaming encoder docs - but if it is a decent streaming encoder
> it should have a reset mechanism.
>
No offense, but saying "that is not true" without looking at the docs is
probably not a great idea.
It's possible to implement an API to do this. The API as it exists (at
least in the stdlib) doesn't. That's what I was saying.
That being said it is probably easier to use lightweight encoders like
> protobufs - still for best efficiency for something like a game that
> doesn’t need general purpose encoding - a custom encoder is probably most
> flexible and efficient.
>
> On Dec 23, 2020, at 6:40 PM, Artur Vianna <lordhowen...@gmail.com> wrote:
>
>
> I'm confused to which part of the thread you're referring to
>
> On Wed, 23 Dec 2020, 21:30 Robert Engels, <reng...@ix.netcom.com> wrote:
>
>> That is not true. Java serialization works similarly. You can hook it do
>> that you send the metadata once during connect, and then encode the data.so
>> no a new connection only needs the metadata and can decode further stream
>> messages. You may need framing resets to simplify things and reduce the
>> overhead depending on the hierarchy of “objects and references”
>>
>> On Dec 23, 2020, at 6:09 PM, Artur Vianna <lordhowen...@gmail.com> wrote:
>>
>>
>> Before using gob was using encoding.BinaryMarshaler, but that would mean
>> the user of the api would need to implement a MarshalBinary for every type,
>> which is kind of cumbersome.
>>
>> An option might be to let the user choose gob, BinaryMarshaler or Json
>> etc to best fit the use case, but that takes the simplicity of only gobs
>> away.
>>
>> I did try your solution to reset the client too but i'm getting
>> inconsistent behaviour, in one server it works and in another it doesn't
>> ("corrupted data or unknown type"). I think synching the server and client
>> will be error prone, while also increasing the use of network.
>>
>> The easiest solution now is to label the package for ≤32 players and test
>> alternative encodings that keep the API as clean as with gob. I took a look
>> at flatbuffers but it will be cumbersome for the user to create the
>> builders, and i really wanted the simplest possible API.
>>
>> Maybe i should try UDP Broadcast too and see what happens, probably chaos
>> :D
>>
>>
>> On Wed, 23 Dec 2020, 20:36 Axel Wagner, <axel.wagner...@googlemail.com>
>> wrote:
>>
>>> No, it wouldn't. Because the encoder keeps state about which
>>> type-information it already sent and wouldn't sent it again - causing the
>>> client to be unable to decode. So you'd also need a new encoder on the
>>> server. And at that point, you're back to the status quo, with one encoder
>>> per client and the duplication of encoding effort.
>>>
>>> A solution would, perhaps, be if the gob API would give you a way to
>>> send *only* the type-info (so you could, if the connection breaks, create a
>>> new encoder, send all the type info, and *then* multicast the encoded
>>> values). But it doesn't.
>>>
>>> Really, I think it's far less effort to just use a different format (and
>>> I would maintain that even json would probably be fine) than trying to make
>>> this work with gob :)
>>>
>>> On Thu, Dec 24, 2020 at 12:20 AM Matthew Zimmerman <mzimmer...@gmail.com>
>>> wrote:
>>>
>>>> If you would "reset" each client with a new decoder each time you make
>>>> a new encoder, everything should work fine. Just would take some
>>>> coordination.
>>>>
>>>> On Wed, Dec 23, 2020, 6:08 PM Artur Vianna <lordhowen...@gmail.com>
>>>> wrote:
>>>>
>>>>> I will look into other protocols, although for now the performance is
>>>>> not an issue in servers with less than 100 players.
>>>>>
>>>>> The problem with io.MultiWriter is that a player inside the group may
>>>>> disconnect or a new player may come in. This means a new io.MultiWriter
>>>>> must be created each time you dispatch, since the group may have changed
>>>>> in
>>>>> the meantime. This would also need a new encoder and then the "duplicate
>>>>> type received" happens.
>>>>>
>>>>> On Wed, 23 Dec 2020, 19:58 'Axel Wagner' via golang-nuts, <
>>>>> golang-nuts@googlegroups.com> wrote:
>>>>>
>>>>>> The issue with that approach is that gob keeps state about which
>>>>>> type-information it still has to send. So if you encode to, say, a
>>>>>> bytes.Buffer, it would encode all type-info on every message sent, which
>>>>>> is
>>>>>> a significant overhead.
>>>>>> TBH, I don't understand why `io.MultiWriter` wouldn't work. It would
>>>>>> be helpful to see the code that causes the error message OP is seeing.
>>>>>>
>>>>>> However, really, gob just doesn't provide a good API for this sorta
>>>>>> thing, as mentioned. The format itself is fine, but the stateful
>>>>>> connection
>>>>>> means that if you don't want to write *exactly* the same data in exactly
>>>>>> the same order to all connections (which can perform poorly and lead to
>>>>>> operational problems with timeouts and intermittently lost connections
>>>>>> and
>>>>>> the like), you are going to have a bad time.
>>>>>> You honestly would fare better with a full-fledged RPC framework such
>>>>>> as gRPC. Or, if you don't want the overhead of its IDL, even json.
>>>>>> Because
>>>>>> at least the "encode once, send to each client" is trivial to solve with
>>>>>> that.
>>>>>>
>>>>>> But, that's just my 2¢ :)
>>>>>>
>>>>>> On Wed, Dec 23, 2020 at 11:43 PM Robert Engels <reng...@ix.netcom.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Yes, that is why you need to create your own protocol. Use the gob
>>>>>>> to encode to a buffer then send the buffer on each of the connections
>>>>>>> using
>>>>>>> your protocol.
>>>>>>>
>>>>>>> On Dec 23, 2020, at 4:19 PM, Matthew Zimmerman <mzimmer...@gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>> My understanding is that gob streams are unique.
>>>>>>>
>>>>>>> From https://golang.org/pkg/encoding/gob/
>>>>>>> "A stream of gobs is self-describing. Each data item in the stream
>>>>>>> is preceded by a specification of its type, expressed in terms of a
>>>>>>> small
>>>>>>> set of predefined types."
>>>>>>>
>>>>>>> In my own rudimentary understanding/terms, it sends the struct
>>>>>>> definition once, then uses shorthand for it afterwards. E.g, how many
>>>>>>> bytes and what order. If you mix and match streams that send
>>>>>>> definitions
>>>>>>> in different orders, then chaos ensues.
>>>>>>>
>>>>>>> I think this is why people use other encoders in the scenario you're
>>>>>>> taking about. For a one to one stream gob works great, but in this
>>>>>>> multi
>>>>>>> scenario I don't think it does.
>>>>>>>
>>>>>>> Matt
>>>>>>>
>>>>>>> On Wed, Dec 23, 2020, 5:07 PM Artur Vianna <lordhowen...@gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> If i create a bytes.Buffer and a gob.Encoder, each time i write to
>>>>>>>> a group of connections i get "duplicate type received" and if i try and
>>>>>>>> reuse the encoder, i get "corrupted data" and "unknown type".
>>>>>>>> It seems i can't use both net.Conn.Write and gob.Encoder.Encode in
>>>>>>>> the same connection, i will try always encoding to a buffer in both
>>>>>>>> unicast
>>>>>>>> and multicast like you said and report if it works.
>>>>>>>>
>>>>>>>> On Wed, 23 Dec 2020, 18:49 Robert Engels, <reng...@ix.netcom.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> You need to encode once to a byte array then send the byte array
>>>>>>>>> on each connection.
>>>>>>>>>
>>>>>>>>> On Dec 23, 2020, at 3:45 PM, meera <lordhowen...@gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I am trying to create a package for game servers using gob. The
>>>>>>>>> current approach is an application level multicasting over TCP,
>>>>>>>>> having a
>>>>>>>>> gob encoder and decoder for each player connection, and set up a
>>>>>>>>> goroutine
>>>>>>>>> to receive and another to dispatch for each one. The code for the
>>>>>>>>> dispatcher is here. But summarized, it simply receives data from a
>>>>>>>>> channel
>>>>>>>>> and encodes it.
>>>>>>>>>
>>>>>>>>> The problem is that if i want to transmit a single piece of data
>>>>>>>>> to all players, this piece of data is encoded again and again for each
>>>>>>>>> connection, doing duplicate work. With less than 100 players this is
>>>>>>>>> not a
>>>>>>>>> problem, but with 300+ my machine is at almost 100% usage and the
>>>>>>>>> profiler
>>>>>>>>> shows that most of it is spent on encoding. Here's the issue on
>>>>>>>>> github.
>>>>>>>>>
>>>>>>>>> I tryied using a io.MultiWriter but gob complains of duplicate
>>>>>>>>> type received, and if i try to write the raw bytes from the
>>>>>>>>> gob.Encoder i
>>>>>>>>> get corrupted data. An option is using UDP Broadcasting but since gob
>>>>>>>>> expects a stream, i'm affraid i will run into unexpected behavior when
>>>>>>>>> packets start to be lost and fragmented.
>>>>>>>>>
>>>>>>>>> Does gob expect a single encoder and decoder to own the stream?
>>>>>>>>> Not allowing two encoders on the server for one decoder on the client?
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> 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.
>>>>>>>>> To view this discussion on the web visit
>>>>>>>>> https://groups.google.com/d/msgid/golang-nuts/0562184e-bbcc-44c9-adbf-37e8d5411c7cn%40googlegroups.com
>>>>>>>>> <https://groups.google.com/d/msgid/golang-nuts/0562184e-bbcc-44c9-adbf-37e8d5411c7cn%40googlegroups.com?utm_medium=email&utm_source=footer>
>>>>>>>>> .
>>>>>>>>>
>>>>>>>>> --
>>>>>>>> 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.
>>>>>>>> To view this discussion on the web visit
>>>>>>>> https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBXN46idvqUbCsGs%2BZbZt%2BCj4MowJ4Ozj3_U9_6-68OWDw%40mail.gmail.com
>>>>>>>> <https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBXN46idvqUbCsGs%2BZbZt%2BCj4MowJ4Ozj3_U9_6-68OWDw%40mail.gmail.com?utm_medium=email&utm_source=footer>
>>>>>>>> .
>>>>>>>>
>>>>>>> --
>>>>>>> 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.
>>>>>>> To view this discussion on the web visit
>>>>>>> https://groups.google.com/d/msgid/golang-nuts/214752B6-2666-4892-A9B8-E4BC4127FD42%40ix.netcom.com
>>>>>>> <https://groups.google.com/d/msgid/golang-nuts/214752B6-2666-4892-A9B8-E4BC4127FD42%40ix.netcom.com?utm_medium=email&utm_source=footer>
>>>>>>> .
>>>>>>>
>>>>>> --
>>>>>> 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.
>>>>>> To view this discussion on the web visit
>>>>>> https://groups.google.com/d/msgid/golang-nuts/CAEkBMfGWtULh8Q3Jqu_gq5m5Si4PvJ1oVSZY7DVhu%3D6hGK83bg%40mail.gmail.com
>>>>>> <https://groups.google.com/d/msgid/golang-nuts/CAEkBMfGWtULh8Q3Jqu_gq5m5Si4PvJ1oVSZY7DVhu%3D6hGK83bg%40mail.gmail.com?utm_medium=email&utm_source=footer>
>>>>>> .
>>>>>>
>>>>> --
>>>>> 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.
>>>>> To view this discussion on the web visit
>>>>> https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBUsmp2sbiEh%3D3z0cC9EhjLig%2B8exXyA05YngBJ-tsC_uA%40mail.gmail.com
>>>>> <https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBUsmp2sbiEh%3D3z0cC9EhjLig%2B8exXyA05YngBJ-tsC_uA%40mail.gmail.com?utm_medium=email&utm_source=footer>
>>>>> .
>>>>>
>>>> --
>> 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.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBU%3DZBR8O9na44vsXCg9NXrH9tdo5xxuBjYqMOYoGU4N0w%40mail.gmail.com
>> <https://groups.google.com/d/msgid/golang-nuts/CAE%3DAWBU%3DZBR8O9na44vsXCg9NXrH9tdo5xxuBjYqMOYoGU4N0w%40mail.gmail.com?utm_medium=email&utm_source=footer>
>> .
>>
>>
--
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.
To view this discussion on the web visit
https://groups.google.com/d/msgid/golang-nuts/CAEkBMfHmz-zt0erOXw3iuVt2vcY%3DGAPKa-3E90z6y553y9_SZg%40mail.gmail.com.
