Is it possible to discover how large something will be when it’s serialized?
I have a data type:
NamedTuple{(:x, :y), Tuple{UInt64, UInt64}}
sizeof tells me this is 16 bytes, and the serialize documentation says that it will add an 8-byte header - which gives 24 bytes. However, experiments show that the serialized form is actually 34 bytes. So sizeof clearly isn’t giving me what I need. Is there something I can use programmatically?
Perhaps not the most efficient, but you can create your own IO type like this:
mutable struct ByteCounterIO <: IO
count::Int
ByteCounterIO() = new(0)
end
Base.write(s::ByteCounterIO, x::UInt8) = s.count += 1
io = ByteCounterIO()
t = (x = 34, y = 18)
using Serialization
serialize(io, t)
io.count
Are you constructing a Serializer object and writing the header once with Serialization.writeheader as suggested in the docs? Unless you do this, Serializer.serialize will write a header each time you serialize something if you use it on an <: IO stream.