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| 1 | +# Copyright (C) 2024 Susanne Claus |
| 2 | +# |
| 3 | +# This file is part of FFCx. (https://www.fenicsproject.org) |
| 4 | +# |
| 5 | +# SPDX-License-Identifier: LGPL-3.0-or-later |
| 6 | + |
| 7 | +import numpy as np |
| 8 | +import pytest |
| 9 | + |
| 10 | + |
| 11 | +def test_tabulate_tensor_integral_add_values(): |
| 12 | + pytest.importorskip("cffi") |
| 13 | + |
| 14 | + from cffi import FFI |
| 15 | + |
| 16 | + # Define custom tabulate tensor function in C with a struct |
| 17 | + # Step 1: Define the function in C and set up the CFFI builder |
| 18 | + ffibuilder = FFI() |
| 19 | + ffibuilder.set_source( |
| 20 | + "_cffi_kernelA", |
| 21 | + r""" |
| 22 | + typedef struct { |
| 23 | + size_t size; |
| 24 | + double* values; |
| 25 | + } cell_data; |
| 26 | +
|
| 27 | + void tabulate_tensor_integral_add_values(double* restrict A, |
| 28 | + const double* restrict w, |
| 29 | + const double* restrict c, |
| 30 | + const double* restrict coordinate_dofs, |
| 31 | + const int* restrict entity_local_index, |
| 32 | + const uint8_t* restrict quadrature_permutation, |
| 33 | + void* custom_data) |
| 34 | + { |
| 35 | + // Cast the void* custom_data to cell_data* |
| 36 | + cell_data* custom_data_ptr = (cell_data*)custom_data; |
| 37 | +
|
| 38 | + // Access the custom data |
| 39 | + size_t size = custom_data_ptr->size; |
| 40 | + double* values = custom_data_ptr->values; |
| 41 | +
|
| 42 | + // Use the values in your computations |
| 43 | + for (size_t i = 0; i < size; i++) { |
| 44 | + A[0] += values[i]; |
| 45 | + } |
| 46 | + } |
| 47 | + """, |
| 48 | + ) |
| 49 | + ffibuilder.cdef( |
| 50 | + """ |
| 51 | + typedef struct { |
| 52 | + size_t size; |
| 53 | + double* values; |
| 54 | + } cell_data; |
| 55 | +
|
| 56 | + void tabulate_tensor_integral_add_values(double* restrict A, |
| 57 | + const double* restrict w, |
| 58 | + const double* restrict c, |
| 59 | + const double* restrict coordinate_dofs, |
| 60 | + const int* restrict entity_local_index, |
| 61 | + const uint8_t* restrict quadrature_permutation, |
| 62 | + void* custom_data); |
| 63 | + """ |
| 64 | + ) |
| 65 | + |
| 66 | + # Step 2: Compile the C code |
| 67 | + ffibuilder.compile(verbose=True) |
| 68 | + |
| 69 | + # Step 3: Import the compiled library |
| 70 | + from _cffi_kernelA import ffi, lib |
| 71 | + |
| 72 | + # Define cell data |
| 73 | + values = np.array([2.0, 1.0], dtype=np.float64) |
| 74 | + size = len(values) |
| 75 | + expected_result = np.array([3.0], dtype=np.float64) |
| 76 | + |
| 77 | + # Define the input arguments |
| 78 | + A = np.zeros(1, dtype=np.float64) |
| 79 | + w = np.array([1.0], dtype=np.float64) |
| 80 | + c = np.array([0.0], dtype=np.float64) |
| 81 | + coordinate_dofs = np.array( |
| 82 | + [0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0], dtype=np.float64 |
| 83 | + ) |
| 84 | + entity_local_index = np.array([0], dtype=np.int32) |
| 85 | + quadrature_permutation = np.array([0], dtype=np.uint8) |
| 86 | + |
| 87 | + # Cast the arguments to the appropriate C types |
| 88 | + A_ptr = ffi.cast("double*", A.ctypes.data) |
| 89 | + w_ptr = ffi.cast("double*", w.ctypes.data) |
| 90 | + c_ptr = ffi.cast("double*", c.ctypes.data) |
| 91 | + coordinate_dofs_ptr = ffi.cast("double*", coordinate_dofs.ctypes.data) |
| 92 | + entity_local_index_ptr = ffi.cast("int*", entity_local_index.ctypes.data) |
| 93 | + quadrature_permutation_ptr = ffi.cast("uint8_t*", quadrature_permutation.ctypes.data) |
| 94 | + |
| 95 | + # Use ffi.from_buffer to create a CFFI pointer from the NumPy array |
| 96 | + values_ptr = ffi.cast("double*", values.ctypes.data) |
| 97 | + |
| 98 | + # Allocate memory for the struct |
| 99 | + custom_data = ffi.new("cell_data*") |
| 100 | + custom_data.size = size |
| 101 | + custom_data.values = values_ptr |
| 102 | + |
| 103 | + # Cast the struct to void* |
| 104 | + custom_data_ptr = ffi.cast("void*", custom_data) |
| 105 | + |
| 106 | + # Call the function |
| 107 | + lib.tabulate_tensor_integral_add_values( |
| 108 | + A_ptr, |
| 109 | + w_ptr, |
| 110 | + c_ptr, |
| 111 | + coordinate_dofs_ptr, |
| 112 | + entity_local_index_ptr, |
| 113 | + quadrature_permutation_ptr, |
| 114 | + custom_data_ptr, |
| 115 | + ) |
| 116 | + |
| 117 | + # Assert the result |
| 118 | + np.testing.assert_allclose(A, expected_result, rtol=1e-5) |
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