NOTE: Packages such as StructArrays.jl, TupleVectors.jl, and TypedTables.jl provide the abstract array interface for Structure-of-Arrays representation which is much more appropriate for many performance-oriented programs.
RecordArrays.jl is a package for using Array-of-Structures representation with
more control than Array{T}. For example, it can be used for creating
task-local state aligned to cache line. Updating a single field at single
index does not mutate other fields.
julia> using RecordArrays
julia> xs = RecordArrays.fill((a = 1, b = 2), 5; align = 64)
5-element RecordArray{NamedTuple{(:a, :b), Tuple{Int64, Int64}},1,…}:
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
julia> all(i -> mod(UInt(pointer(xs, i)), 64) == 0, eachindex(xs))
true
julia> xs[1] = (a = 111, b = 222);
julia> xs
5-element RecordArray{NamedTuple{(:a, :b), Tuple{Int64, Int64}},1,…}:
(a = 111, b = 222)
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
julia> xs.a
5-element FieldArray{:a,Int64,1,…}:
111
1
1
1
1
julia> xs.a[2] = 11111;
julia> xs
5-element RecordArray{NamedTuple{(:a, :b), Tuple{Int64, Int64}},1,…}:
(a = 111, b = 222)
(a = 11111, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)
julia> x3 = view(xs, 3) # acts like a `NamedTuple` of `Ref`s
1-element RecordArray{NamedTuple{(:a, :b), Tuple{Int64, Int64}},0,…}:
(a = 1, b = 2)
julia> x3.a[]
1
julia> x3.a[] = 333;
julia> xs
5-element RecordArray{NamedTuple{(:a, :b), Tuple{Int64, Int64}},1,…}:
(a = 111, b = 222)
(a = 11111, b = 2)
(a = 333, b = 2)
(a = 1, b = 2)
(a = 1, b = 2)Use RecordArray{T}(undef, dims) to allocate a new uninitialized array:
julia> using RecordArrays
julia> xs = RecordArray{Some{Union{Nothing,Int}}}(undef, 3);
julia> xs .= Some.(1:3)
3-element RecordArray{Some{Union{Nothing, Int64}},1,…}:
1
2
3Another way to allocate a new array is to use RecordArrays.unsafe_zeros:
julia> using RecordArrays
julia> xs = RecordArrays.unsafe_zeros(NTuple{5, UInt8}, 3)
3-element RecordArray{NTuple{5, UInt8},1,…}:
(0x00, 0x00, 0x00, 0x00, 0x00)
(0x00, 0x00, 0x00, 0x00, 0x00)
(0x00, 0x00, 0x00, 0x00, 0x00)