It seems the URL http://google3/experimental/users/acozzette/map_reflection_test.cc?rcl=158157727 is not working, I can not access it :-(
Regards, Qian Zhang On Wed, Jun 7, 2017 at 1:32 AM, Adam Cozzette <[email protected]> wrote: > Here's an example of how to do it: http://google3/ > experimental/users/acozzette/map_reflection_test.cc?rcl=158157727 It's a > bit clunky because you just have to reflect on the map field like you would > a repeated field, but it works. > > On Mon, Jun 5, 2017 at 6:08 PM, Qian Zhang <[email protected]> wrote: > >> Thanks Adam. >> >> Can you please let me know which API I can use to do reflection on a map? >> >> >> Regards, >> Qian Zhang >> >> On Mon, Jun 5, 2017 at 11:42 PM, Adam Cozzette <[email protected]> >> wrote: >> >>> Doing reflection on a map is a little bit tricky, but the way to do it >>> is to treat it as a repeated field since that is how it is actually >>> represented on the wire. A map is a stored as a repeated message field, >>> where in each message the key is field 1 and the value is field 2. >>> >>> On Mon, Jun 5, 2017 at 1:37 AM, Qian Zhang <[email protected]> wrote: >>> >>>> Hi Adam, >>>> >>>> We are using picojson <https://github.com/kazuho/picojson> to parse >>>> the JSON file. >>>> >>>> After more debugging, I think I have found the root cause: In the code >>>> here >>>> <https://github.com/apache/mesos/blob/1.2.0/3rdparty/stout/include/stout/protobuf.hpp#L575>, >>>> we are trying to find a field by the key of an entry in a map, obviously it >>>> will fail since the key of any map entries is not in the protobuf message >>>> definition (the .proto file), and to avoid finding field by a map entry's >>>> key, in this method >>>> <https://github.com/apache/mesos/blob/1.2.0/3rdparty/stout/include/stout/protobuf.hpp#L387:L407>, >>>> we need to check if "field->is_map()" is true which is currently missed, if >>>> the field is a map, then we should use the reflection to construct a map >>>> message, however I do not find a method in protobuf to do that, I find a >>>> lot of "Addxxx()" methods (e.g., "AddString()", "AddInt64()", etc.), but >>>> not a method for adding a map. There is a method >>>> "InsertOrLookupMapValue()", but that is a private method which I can not >>>> call in my code. >>>> >>>> So can you please suggest how to add a map message? Thanks! >>>> >>>> >>>> Regards, >>>> Qian Zhang >>>> >>>> On Sat, Jun 3, 2017 at 1:02 AM, Adam Cozzette <[email protected]> >>>> wrote: >>>> >>>>> It looks to me like your JSON syntax is right. Could you post the C++ >>>>> code you are using to parse the JSON file? >>>>> >>>>> On Fri, Jun 2, 2017 at 1:16 AM, Qian Zhang <[email protected]> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I have a C++ project in which there is a .proto file, and in that >>>>>> file, there is protobuf message which has a map field: >>>>>> "map<string, string> annotations = 5;" >>>>>> >>>>>> And the JSON file to be parsed with that .proto file has the >>>>>> following content: >>>>>> "annotations": { >>>>>> "com.example.key1": "value1", >>>>>> "com.example.key2": "value2" >>>>>> } >>>>>> >>>>>> The .proto file is in proto2 syntax (it has "syntax = "proto2";" at >>>>>> the beginning) and I am using protobuf-3.3.0, the compilation succeed, >>>>>> but >>>>>> I found the annotation map always has only one entry, and both the >>>>>> entry's >>>>>> key and value are "" which is obviously not correct. >>>>>> >>>>>> Any suggestions? >>>>>> >>>>>> -- >>>>>> 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.
