feat: add support for nested PDUs

Project.toml

@@ -2,3 +2,7 @@ name = "PDUs"
 uuid = "07db6e9f-91ad-4fbd-9fd8-5722e51e9a72"
 authors = ["Mandar Chitre <mandar@nus.edu.sg>"]
 version = "0.1.0"
+
+[deps]
+
+[compat]

src/PDUs.jl

@@ -174,7 +174,8 @@ function Base.read(io::IO, T::Type{<:PDU}; nbytes=missing)
  v = n === nothing ? varread(io, V) : V[read(io, V) for _ ∈ 1:n]
  push!(data, f => F <: AbstractString ? strip(String(v), ['\0']) : ptoh.(v))
  else
- push!(data, f => read(io, F))
+ n = length(T, Val(f), PDUInfo(nbytes, s -> lookup(data, s)))
+ push!(data, f => read(io, F; nbytes=something(n, missing)))
  end
  end
  T(map(kv -> kv[2], data)...)

test/runtests.jl

@@ -67,6 +67,10 @@ using PDUs
  @test f1 == f2
  @test length(buf) == 18 + 255
 
+end
+
+@testset "strings" begin
+
  struct TestPDU <: PDU
  n::UInt8
  s::String
@@ -105,3 +109,55 @@ using PDUs
  @test f1 == f2
 
 end
+
+@testset "nested" begin
+
+ struct InnerPDU <: PDU
+ a::UInt16
+ b::String
+ end
+
+ struct OuterPDU <: PDU
+ n::UInt16
+ inner::InnerPDU
+ end
+
+ f1in = InnerPDU(0x1234, "hello")
+ f1 = OuterPDU(0x5678, f1in)
+ buf = Vector{UInt8}(f1)
+ f2 = OuterPDU(buf)
+
+ @test f1.n == f2.n
+ @test f1.inner == f2.inner
+ @test f1 == f2
+ @test length(buf) == 10
+ @test buf == [0x56, 0x78, 0x12, 0x34, 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f]
+
+ PDUs.length(::Type{InnerPDU}, ::Val{:b}, info) = info.get(:a)
+
+ f1in = InnerPDU(0x05, "hello")
+ f1 = OuterPDU(0x5678, f1in)
+ buf = Vector{UInt8}(f1)
+ f2 = OuterPDU(buf)
+
+ @test f1.n == f2.n
+ @test f1.inner == f2.inner
+ @test f1 == f2
+ @test length(buf) == 9
+ @test buf == [0x56, 0x78, 0x00, 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f]
+
+ PDUs.length(::Type{InnerPDU}, ::Val{:b}, info) = info.length - 2
+ PDUs.length(::Type{OuterPDU}, ::Val{:inner}, info) = info.length - 2
+
+ f1in = InnerPDU(0x1234, "hello")
+ f1 = OuterPDU(0x5678, f1in)
+ buf = Vector{UInt8}(f1)
+ f2 = OuterPDU(buf)
+
+ @test f1.n == f2.n
+ @test f1.inner == f2.inner
+ @test f1 == f2
+ @test length(buf) == 9
+ @test buf == [0x56, 0x78, 0x12, 0x34, 0x68, 0x65, 0x6c, 0x6c, 0x6f]
+
+end