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. 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