Does setting the same "primitive" field repeatedly cause size to grow?

[vlo...@gmail.com]

I don't see this explicitly called out in https://capnproto.org/cxx.html but I just wanted to double-check that something like this:


capnp::MallocMessageBuilder builder;

auto msg = builder.initRoot<MyMessage>();

auto nested = msg.initSomeStruct();

for (int i = 0; i < 100000; i++) {

    nested.setField(i);

    write over the wire(nested);

}

Doesn't cause arena allocation & the serialized wire size is going to be constant for all messages (i.e. it's going to continue clobbering the existing space for that field). It sounded like the only situation

was around re-initializing an existing struct or copying messages in. Just wanted to make sure that my understanding is correct & setting non-pointer fields is fine. I imagine that probably lists of

primitives are immune to this.

Thanks,

Vitali

[Ian Denhardt]

Correct, setting a field with a primitive type will not allocate
additional space.

-Ian

Quoting vlo...@gmail.com (2020-04-16 16:53:46)

> I don't see this explicitly called out

> in� [1]https://capnproto.org/cxx.html� but I just wanted to

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