On Tuesday, March 19, 2019 at 8:25:38 PM UTC-4, Adam Cozzette wrote: > > Oh, I am talking about the binary format in particular. In that scenario > it's important for unknown enum values to be handled in some way, since you > might want to add a new enum value but it should still be parseable by > older binaries. >
>From reading the language guide, etc, I take it that the default to the first value. That can be anything, 0, 1, 99, whatever. I could be wrong there, however; my current interest in Protobuf is in the v2 descriptors only, at the moment. > On Tue, Mar 19, 2019 at 4:14 PM Michael Powell <[email protected] > <javascript:>> wrote: > >> >> >> On Tuesday, March 19, 2019 at 6:50:37 PM UTC-4, Adam Cozzette wrote: >>> >>> Not exactly, by unknown enum value I mean an enum value that doesn't >>> appear in the enum definition. For example let's say your enum has only >>> values 0, 1, and 2 but you parse a 3. This could happen if the message was >>> serialized by another binary using a newer version of the schema. Proto2 >>> will store unknown enum values in the unknown field set whereas proto3 will >>> just store them normally in the field. >>> >> >> I think in the above scenario, that would likely break whether v2 or v3, >> but I could be wrong. >> >> I would have to re-read the language guide. You can parse an ordinal >> value where the Enumeration was expected? >> >> i.e. UNKNOWN = 0; >> >> Would accept 0 or UNKNOWN? >> >> Are we talking descriptor / protobuf specification level? Or binary >> level? >> >> I do not read any biases where unexpected ordinal values are concerned, >> but I would expect that it fail any sort of verification. >> >> That being said, specification versioning is a concern regardless of >> whether v2 or v3, I think, and not just with Protocol Buffers. It's a >> concern for this type of framework, regardless. >> >> On Thu, Mar 14, 2019 at 7:29 PM Jason Huang <[email protected]> wrote: >>> >>>> thanks for your reply , as for the `unknown enum values` , do you mean >>>> the case of a unseted enum field ? >>>> >>>> On Friday, 15 March 2019 02:12:31 UTC+8, Adam Cozzette wrote: >>>>> >>>>> Going from proto3 to proto2 should be fine. There are some slight >>>>> differences but I can't think of any major problems. The only thing that >>>>> comes to mind is that proto2 handles unknown enum values a little bit >>>>> differently from proto3. I doubt that would be a problem but if you want >>>>> to >>>>> be extra cautious you could double-check that you're not storing any >>>>> unknown enum values. >>>>> >>>>> However, there is no need to downgrade to version 2.6.1 and if >>>>> anything that would only introduce bugs and make the code slower. The >>>>> proto2 semantics are still fully supported in all versions going forward, >>>>> so all you have to do is put syntax = "proto2"; at the top of your >>>>> .proto files. You can stick with 3.6.1 or even upgrade to any newer >>>>> version. >>>>> >>>>> On Thu, Mar 14, 2019 at 10:21 AM Jason Huang <[email protected]> >>>>> wrote: >>>>> >>>>>> i chose proto3 for cache （serialize） for my application , and it have >>>>>> run for several month . but now i wanna change my mind for proto2 , >>>>>> because >>>>>> the hasField is really needed . >>>>>> >>>>>> the problem is , there're still lots of data in the cache which are >>>>>> serialized with proto3 , if i can't deserialize with them with proto2 . >>>>>> it >>>>>> will be unacceptable . >>>>>> >>>>>> my question is , is it safe to switch from proto3 to proto2 ? i made >>>>>> some test i could work in some case . but i'm afraid this is not full >>>>>> coverage test . >>>>>> >>>>>> my current proto3 version is 3.6.1 , and the proto2 version i want to >>>>>> use is 2.6.1 >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "Protocol Buffers" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>> send an email to [email protected]. >>>>>> To post to this group, send email to [email protected]. >>>>>> Visit this group at https://groups.google.com/group/protobuf. >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Protocol Buffers" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/protobuf. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Protocol Buffers" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at https://groups.google.com/group/protobuf. >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. 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