Add error

Author: gdalle

ext/SparseMatrixColoringsCUDAExt.jl

@@ -100,16 +100,36 @@ end
 for R in (:ColumnColoringResult, :RowColoringResult, :StarSetColoringResult)
     # loop to avoid method ambiguity
     @eval function SMC.decompress!(
-        A::CuSparseMatrixCSC, B::CuMatrix, result::SMC.$R{<:CuSparseMatrixCSC}
+        A::CuSparseMatrixCSC,
+        B::CuMatrix,
+        result::SMC.$R{<:CuSparseMatrixCSC},
+        uplo::Symbol=:F,
     )
+        if uplo != :F
+            throw(
+                SMC.UnsupportedDecompressionError(
+                    "Single-triangle decompression is not supported on GPU matrices"
+                ),
+            )
+        end
         compressed_indices = result.additional_info.compressed_indices_gpu_csc
         copyto!(A.nzVal, view(B, compressed_indices))
         return A
     end
 
     @eval function SMC.decompress!(
-        A::CuSparseMatrixCSR, B::CuMatrix, result::SMC.$R{<:CuSparseMatrixCSR}
+        A::CuSparseMatrixCSR,
+        B::CuMatrix,
+        result::SMC.$R{<:CuSparseMatrixCSR},
+        uplo::Symbol=:F,
     )
+        if uplo != :F
+            throw(
+                SMC.UnsupportedDecompressionError(
+                    "Single-triangle decompression is not supported on GPU matrices"
+                ),
+            )
+        end
         compressed_indices = result.additional_info.compressed_indices_gpu_csr
         copyto!(A.nzVal, view(B, compressed_indices))
         return A

src/decompression.jl

@@ -106,6 +106,14 @@ function compress(
     return Br, Bc
 end
 
+struct UnsupportedDecompressionError
+    msg::String
+end
+
+function Base.showerror(io::IO, err::UnsupportedDecompressionError)
+    return print(io, "UnsupportedDecompressionError: $(err.msg)")
+end
+
 """
     decompress(B::AbstractMatrix, result::AbstractColoringResult{_,:column/:row})
     decompress(Br::AbstractMatrix, Bc::AbstractMatrix, result::AbstractColoringResult{_,:bidirectional})

test/cuda.jl

@@ -2,6 +2,7 @@ using CUDA.CUSPARSE: CuSparseMatrixCSC, CuSparseMatrixCSR
 using LinearAlgebra
 using SparseArrays
 using SparseMatrixColorings
+import SparseMatrixColorings as SMC
 using StableRNGs
 using Test
 
@@ -51,5 +52,11 @@ end;
             A0 = T(sparse(Symmetric(sprand(rng, n, n, p))))
             test_coloring_decompression(A0, problem, algo; gpu=true)
         end
+        A0 = T(sparse(Diagonal(ones(10))))
+        result = coloring(A0, problem, algo)
+        B = compress(A0, result)
+        @test_throws SMC.UnsupportedDecompressionError decompress!(
+            similar(A0), B, result, :U
+        )
     end
 end;

test/result.jl

@@ -1,4 +1,4 @@
-using SparseMatrixColorings: group_by_color
+using SparseMatrixColorings: group_by_color, UnsupportedDecompressionError
 using Test
 
 @testset "Group by color" begin
@@ -31,3 +31,8 @@ end
     B = compress(A, coloring(A, problem, algo))
     @test size(B, 1) == 0
 end
+
+@testset "Errors" begin
+    e = SparseMatrixColorings.UnsupportedDecompressionError("hello")
+    @test sprint(showerror, e) == "UnsupportedDecompressionError: hello"
+end