Test file for Iterator2D

iterator_test.jl

function test(m, n, k)
    A = randn(m, n)
    @time begin
        s = 0.0
        for j = 1:k
            for i = 1:length(A)
                s += A[i]
            end
        end
    end
    try
        gc_disable()
        @time begin
            s = 0.0
            for j = 1:k
                for i = Iter.Iterator(A)
                    s += A[i]
                end
            end
        end
    finally
        gc_enable()
    end
end

test(10, 10, 1)

@sprofile test(1000, 1001, 1)

testsimple.jl

abstract IteratorState

import Base.assign, Base.done, Base.next, Base.ref, Base.start


immutable Iterator1D
    ni::Int
    stridei::Int
    first_index::Int
end

immutable Iterator1DState <: IteratorState
    i::Int
    index::Int
end

start(iter::Iterator1D) = Iterator1DState(1, iter.first_index)

next(iter::Iterator1D, state::Iterator1DState) = state, Iterator1DState(state.i+1, state.index + iter.stridei)

done(iter::Iterator1D, state::Iterator1DState) = state.i > iter.ni




immutable Iterator2D
    ni::Int
    nj::Int
    stridei::Int
    stridej::Int
    first_index::Int
end

immutable Iterator2DState <: IteratorState
    i::Int
    j::Int
    index::Int
end

start(iter::Iterator2D) = Iterator2DState(1, 1, iter.first_index)

next(iter::Iterator2D, state::Iterator2DState) = (state.i+1 <= iter.ni) ? (state, Iterator2DState(state.i+1, state.j, state.index + iter.stridei)) : (state, Iterator2DState(1, state.j+1, iter.first_index+state.j*iter.stridej))

done(iter::Iterator2D, state::Iterator2DState) = state.j > iter.nj




ref(A::StridedArray, state::IteratorState) = parent(A)[state.index]

parent(A::Array) = A
parent(A::SubArray) = A.parent
first_index(A::Array) = 1
first_index(A::SubArray) = A.first_index



function test{T}(A::Array{T}, k)
    gc_disable()
    @time begin
        s = zero(T)
        for j = 1:k
            for i = 1:length(A)
                s += A[i]
            end
        end
    end
    @time begin
        s2 = zero(T)
        for j = 1:k
            for i = Iterator2D(size(A,1), size(A,2), 1, size(A,1), 1)
#             for i = Iterator1D(length(A), 1, 1)
                s2 += A[i]
            end
        end
    end
    @assert s == s2
    @show s
    gc_enable()
end

test(randn(10,11), 1)

println()

@sprofile test(randn(1000,1001), 10)