Safer serialization of ::SubArray{T,N,A<:Array}

base/serialize.jl

@@ -3,6 +3,7 @@
 module Serializer
 
 import Base: GMP, Bottom, svec, unsafe_convert, uncompressed_ast
+using Base: ViewIndex, dimsize
 
 export serialize, deserialize
 
@@ -191,15 +192,27 @@ function serialize(s::SerializationState, a::Array)
 end
 
 function serialize{T,N,A<:Array}(s::SerializationState, a::SubArray{T,N,A})
-    if !isbits(T) || stride(a,1)!=1
-        return serialize(s, copy(a))
-    end
-    writetag(s.io, ARRAY_TAG)
-    serialize(s, T)
-    serialize(s, size(a))
-    serialize_array_data(s.io, a)
+    b = trimmedsubarray(a)
+    serialize_any(s, b)
+end
+
+function trimmedsubarray{T,N,A<:Array}(V::SubArray{T,N,A})
+    dest = Array(eltype(V), trimmedsize(V))
+    copy!(dest, V)
+    _trimmedsubarray(dest, V, (), V.indexes...)
 end
 
+trimmedsize(V) = _trimmedsize(V, (), V.indexes...)
+_trimmedsize(V, trimsz) = trimsz
+_trimmedsize(V, trimsz, index, indexes...) = _trimmedsize(V, (trimsz..., dimsize(V.parent, length(trimsz)+1, index)), indexes...)
+
+_trimmedsubarray{T,N,P,I,LD}(A, V::SubArray{T,N,P,I,LD}, newindexes) = SubArray{T,N,P,I,LD}(A, newindexes, size(V), 1, 1)
+_trimmedsubarray(A, V, newindexes, index::ViewIndex, indexes...) = _trimmedsubarray(A, V, (newindexes..., trimmedindex(V.parent, length(newindexes)+1, index)), indexes...)
+
+trimmedindex(P, d, i::Real) = oftype(i, 1)
+trimmedindex(P, d, i::Colon) = i
+trimmedindex(P, d, i::AbstractVector) = oftype(i, 1:length(i))
+
 function serialize{T<:AbstractString}(s::SerializationState, ss::SubString{T})
     # avoid saving a copy of the parent string, keeping the type of ss
     serialize_any(s, convert(SubString{T}, convert(T,ss)))

test/serialize.jl

@@ -232,6 +232,30 @@ create_serialization_stream() do s # slices
     @test deserialize(s) == slc2
 end
 
+# Objects that have a SubArray as a type in a type-parameter list
+module ArrayWrappers
+
+immutable ArrayWrapper{T,N,A<:AbstractArray} <: AbstractArray{T,N}
+    data::A
+end
+Base.size(A::ArrayWrapper) = size(A.data)
+Base.size(A::ArrayWrapper, d) = size(A.data, d)
+Base.getindex(A::ArrayWrapper, i::Real...) = getindex(A.data, i...)
+
+end
+
+let A = rand(3,4)
+    for B in (sub(A, :, 2:4), slice(A, 2, 1:3))
+        C = ArrayWrappers.ArrayWrapper{Float64,2,typeof(B)}(B)
+        io = IOBuffer()
+        serialize(io, C)
+        seek(io, 0)
+        Cd = deserialize(io)
+        @test size(Cd) == size(C)
+        @test Cd == B
+    end
+end
+
 # Function
 serialize_test_function() = 1
 serialize_test_function2 = ()->1