Hi Mohamed, sorry for the delay getting back to you. I had forgotten about
this but there is a known issue that protobuf lite does not contain the
well-known protos: https://github.com/google/protobuf/issues/1889 Even if
you tweak the build to include them, there is still the issue that the
generated code from them will rely on symbols which are not present in the
lite runtime.
I think there are two possible workarounds for now:
1) You could just link against the full runtime but continue using
optimize_for = LITE in your .proto files. This way you would still have the
code size benefit of having generated descriptors omitted from your binary,
but you would have extra library code, so you would have to look at the
size of your binary and see if this makes sense in your case.
2) You could essentially copy any.proto to another directory in your
project and give it a different package name. Then you could use this
private version of Any and it would be wire-compatible with
google.protobuf.Any.
On Thu, Dec 1, 2016 at 10:48 AM, Mohamed Koubaa <mohamed.kou...@ansys.com>
wrote:
> Hello,
>
> This works as long as my test project links against the full protobuf
> runtime. Attempting to link against the lite runtime produces the
> following unresolved symbols:
>
> error LNK2001: unresolved external symbol "public: __cdecl
> google::protobuf::Any::Any(void)" (??0Any@protobuf@google@@QEAA@XZ)
>
> error LNK2001: unresolved external symbol "void __cdecl
> google::protobuf::protobuf_AddDesc_google_2fprotobuf_2fany_2eproto(void)"
> (?protobuf_AddDesc_google_2fprotobuf_2fany_2eproto@protobuf@google@@YAXXZ)
>
> error LNK2001: unresolved external symbol "public: virtual bool __cdecl
> google::protobuf::Any::MergePartialFromCodedStream(class
> google::protobuf::io::CodedInputStream *)" (?MergePartialFromCodedStream@
> Any@protobuf@google@@UEAA_NPEAVCodedInputStream@io@23@@Z)
>
> error LNK2001: unresolved external symbol "public: virtual int __cdecl
> google::protobuf::Any::ByteSize(void)const " (?ByteSize@Any
> @protobuf@google@@UEBAHXZ)
>
> error LNK2001: unresolved external symbol "public: void __cdecl
> google::protobuf::Any::MergeFrom(class google::protobuf::Any const &)"
> (?MergeFrom@Any@protobuf@google@@QEAAXAEBV123@@Z)
>
> error LNK2001: unresolved external symbol "public: static class
> google::protobuf::Any const & __cdecl
> google::protobuf::Any::default_instance(void)"
> (?default_instance@Any@protobuf@google@@SAAEBV123@XZ)
>
>
> Thanks,
> Mohamed Koubaa
> Software Developer
> ANSYS Inc
>
> On Thu, Dec 1, 2016 at 1:36 PM, Mohamed Koubaa <mohamed.kou...@ansys.com>
> wrote:
>
>> Hello,
>>
>> FWIW, this is the boilerplate I use for my proto3.0.0 project. It
>> depends on GetTypeName() whose future is uncertain in the lite runtime. It
>> appears to work in one of my tests but I am not sure if I am missing
>> something subtle. I'm using SerializeWithCachedSizesToArray because I
>> learned that it is faster for large messages because it does not compute
>> the size twice.
>>
>> static void PackInto(google::protobuf::Any* target, const
>> google::protobuf::MessageLite& msg)
>> {
>> int msg_size = msg.ByteSize();
>> char* msg_buffer = new char[msg_size];
>>
>>
>> msg.SerializeWithCachedSizesToArray((google::protobuf::uint8*)msg_buffer);
>> //avoids double
>> target->set_type_url(msg.GetTypeName());
>> target->set_value(msg_buffer,msg_size);
>>
>> delete[] msg_buffer;
>> }
>>
>> static void UnpackFrom(const google::protobuf::Any& source,
>> google::protobuf::MessageLite* msg)
>> {
>> EXPECT_EQ(source.type_url(), msg->GetTypeName()); //Could be
>> converted to an assert or CHECK style macro in a non-test project
>> msg->ParseFromArray(source.value().c_str(), source.value().size());
>> }
>>
>> Thanks,
>> Mohamed Koubaa
>> Software Developer
>> ANSYS Inc
>>
>> On Tue, Nov 29, 2016 at 8:22 PM, Adam Cozzette <acozze...@google.com>
>> wrote:
>>
>>> Right now there doesn't seem to be a consensus around adding built-in
>>> support for Any in the lite runtime, so I suspect that the status quo will
>>> probably remain for now. If you would like to use Any with the lite
>>> runtime, I think it's probably best to just manually serialize and parse to
>>> and from your Any fields, since that will work even if it involves a little
>>> extra boilerplate.
>>>
>>> On Tue, Nov 29, 2016 at 11:20 AM, Mohamed Koubaa <
>>> mohamed.kou...@ansys.com> wrote:
>>>
>>>> Hello,
>>>>
>>>> I am sorry to bring back an old thread, but the outcome is not clear.
>>>> Is there either an intent or any ongoing work to support Any types with the
>>>> lite runtime?
>>>>
>>>> Best Regards,
>>>> Mohamed Koubaa
>>>> Software Developer
>>>> ANSYS Inc
>>>>
>>>> On Mon, Oct 10, 2016 at 3:00 PM, 'Adam Cozzette' via Protocol Buffers <
>>>> protobuf@googlegroups.com> wrote:
>>>>
>>>>>
>>>>> On Fri, Oct 7, 2016 at 2:16 PM, Arpit Baldeva <abald...@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Thanks for the info.
>>>>>>
>>>>>> I feel like without pack/unpack/Is method, the utility of Any will
>>>>>> diminish. For example, the rpc status proto (
>>>>>> https://github.com/googleapis/googleapis/blob/master/google
>>>>>> /rpc/status.proto) uses repeated Any field. It'd not be possible to
>>>>>> write code like one described here - https://developers.google.co
>>>>>> m/protocol-buffers/docs/proto3#any because you won't know if it is
>>>>>> safe to convert value to a give message. I also came across this post
>>>>>> after
>>>>>> my post which marks the request as a bug currently -
>>>>>> https://github.com/google/protobuf/issues/1974
>>>>>>
>>>>>
>>>>> What you're saying makes sense, we might want to consider just
>>>>> updating Any to have first-class support for MessageLite. In C++ this
>>>>> would
>>>>> be straightforward but in Java, for example, we would need to think
>>>>> carefully about how to do it because in Java lite we don't currently have
>>>>> the message names available at runtime.
>>>>>
>>>>> Regarding the future of GetTypeName, though it has overhead, feel like
>>>>>> it could have many utilities outside of the Any support as well. I don't
>>>>>> have concrete use case in mind though as I am just starting on protobuf.
>>>>>> This brings another important question that I was wondering if somebody
>>>>>> already has data around. There are two options for reducing code bloat.
>>>>>> One
>>>>>> is Lite and another is code_size. I understand that lite reduces code
>>>>>> bloat
>>>>>> by removing descriptors/reflections related code (thereby reducing the
>>>>>> library size) and code_size reduces the code bloat by generating less
>>>>>> code
>>>>>> per message but puts descriptors/reflectors back in(shared code). And the
>>>>>> recommendation is to choose code_size option if number of message are
>>>>>> much
>>>>>> higher compared to the overhead caused by the size of lib. Are there any
>>>>>> benchmarks around what the size of the library is (and lite version) and
>>>>>> what is the per message overhead saved by the code_size option? And the
>>>>>> performance drop with code_size option?
>>>>>>
>>>>>
>>>>> Here's one way to break it down.
>>>>>
>>>>> SPEED:
>>>>> - Fixed overhead of full runtime (e.g. the Message class)
>>>>> - Per-message overhead of generated parsing/serialization code
>>>>> - Per-message overhead of generated descriptors
>>>>>
>>>>> LITE_RUNTIME:
>>>>> - Fixed overhead of lite runtime (e.g. includes MessageLite but not
>>>>> Message)
>>>>> - Per-message overhead of generated parsing/serialization code
>>>>>
>>>>> CODE_SIZE:
>>>>> - Fixed overhead of full runtime (e.g. the Message class)
>>>>> - Per-message overhead of generated descriptors
>>>>>
>>>>> SPEED and LITE_RUNTIME should be about the same speed because they
>>>>> both benefit from the fast generated code for parsing and serialization,
>>>>> while CODE_SIZE is much slower because it relies on reflection instead of
>>>>> generated code. My impression is that CODE_SIZE is not really a good
>>>>> choice
>>>>> unless you have an unusual situation where you have a large number of
>>>>> protos and are really tight on code size. A basic rule of thumb would be
>>>>> to
>>>>> use the default (SPEED) on servers and LITE_RUNTIME on mobile.
>>>>>
>>>>> I'm not sure offhand of the actual numbers for how binary size and
>>>>> speed differ between the three choices--Gerben (CC'd), do you happen to
>>>>> know some numbers for this question?
>>>>>
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>>>>
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>>>
>>>
>>
>
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