Add b2nd_nans method #624

blosc/b2nd.c

@@ -395,6 +395,23 @@ int b2nd_zeros(b2nd_context_t *ctx, b2nd_array_t **array) {
 }
 
 
+int b2nd_nans(b2nd_context_t *ctx, b2nd_array_t **array) {
+  BLOSC_ERROR_NULL(ctx, BLOSC2_ERROR_NULL_POINTER);
+  BLOSC_ERROR_NULL(array, BLOSC2_ERROR_NULL_POINTER);
+
+  BLOSC_ERROR(array_new(ctx, BLOSC2_SPECIAL_NAN, array));
+
+  const int32_t typesize = (*array)->sc->typesize;
+  if (typesize != 4 && typesize != 8)
+  {
+    BLOSC_TRACE_ERROR("Unsupported typesize for NaN");
+    return BLOSC2_ERROR_DATA;
+  }
+
+  return BLOSC2_ERROR_SUCCESS;
+}
+
+
 int b2nd_full(b2nd_context_t *ctx, b2nd_array_t **array, const void *fill_value) {
   BLOSC_ERROR_NULL(ctx, BLOSC2_ERROR_NULL_POINTER);
   BLOSC_ERROR_NULL(array, BLOSC2_ERROR_NULL_POINTER);

doc/reference/b2nd.rst

@@ -41,6 +41,7 @@ Constructors
 .. doxygenfunction:: b2nd_uninit
 .. doxygenfunction:: b2nd_empty
 .. doxygenfunction:: b2nd_zeros
+.. doxygenfunction:: b2nd_nans
 .. doxygenfunction:: b2nd_full
 
 From/To buffer

include/b2nd.h

@@ -193,6 +193,19 @@ BLOSC_EXPORT int b2nd_empty(b2nd_context_t *ctx, b2nd_array_t **array);
 BLOSC_EXPORT int b2nd_zeros(b2nd_context_t *ctx, b2nd_array_t **array);
 
 
+/**
+ * Create an array, with NaN being used as the default value for
+ * uninitialized portions of the array. Should only be used with type sizes
+ * of either 4 or 8. Other sizes generate an error.
+ *
+ * @param ctx The b2nd context for the new array.
+ * @param array The memory pointer where the array will be created.
+ *
+ * @return An error code.
+ */
+BLOSC_EXPORT int b2nd_nans(b2nd_context_t *ctx, b2nd_array_t **array);
+
+
 /**
  * Create an array, with @p fill_value being used as the default value for
  * uninitialized portions of the array.

tests/b2nd/test_b2nd_nans.c

@@ -0,0 +1,105 @@
+/*********************************************************************
+  Blosc - Blocked Shuffling and Compression Library
+
+  Copyright (c) 2021  Blosc Development Team <[email protected]>
+  https://blosc.org
+  License: BSD 3-Clause (see LICENSE.txt)
+
+  See LICENSE.txt for details about copyright and rights to use.
+**********************************************************************/
+
+#include "test_common.h"
+#include <math.h>
+
+CUTEST_TEST_SETUP(nans) {
+  blosc2_init();
+
+  // Add parametrizations
+  CUTEST_PARAMETRIZE(typesize, uint8_t, CUTEST_DATA(
+      4, 8
+  ));
+  CUTEST_PARAMETRIZE(shapes, _test_shapes, CUTEST_DATA(
+      {0, {0}, {0}, {0}}, // 0-dim
+      {1, {5}, {3}, {2}}, // 1-idim
+      {2, {20, 0}, {7, 0}, {3, 0}}, // 0-shape
+      {2, {20, 10}, {7, 5}, {3, 5}}, // 0-shape
+      {2, {14, 10}, {8, 5}, {2, 2}}, // general,
+      {3, {12, 10, 14}, {3, 5, 9}, {3, 4, 4}}, // general
+      {3, {10, 21, 30, 55}, {8, 7, 15, 3}, {5, 5, 10, 1}}, // general,
+  ));
+  CUTEST_PARAMETRIZE(backend, _test_backend, CUTEST_DATA(
+      {false, false},
+      {true, false},
+      {true, true},
+      {false, true},
+  ));
+}
+
+
+CUTEST_TEST_TEST(nans) {
+  CUTEST_GET_PARAMETER(backend, _test_backend);
+  CUTEST_GET_PARAMETER(shapes, _test_shapes);
+  CUTEST_GET_PARAMETER(typesize, uint8_t);
+
+  char *urlpath = "test_nans.b2frame";
+  blosc2_remove_urlpath(urlpath);
+
+  blosc2_cparams cparams = BLOSC2_CPARAMS_DEFAULTS;
+  cparams.nthreads = 2;
+  cparams.typesize = typesize;
+  blosc2_storage b2_storage = {.cparams=&cparams};
+  if (backend.persistent) {
+    b2_storage.urlpath = urlpath;
+  }
+  b2_storage.contiguous = backend.contiguous;
+
+  b2nd_context_t *ctx = b2nd_create_ctx(&b2_storage, shapes.ndim, shapes.shape,
+                                        shapes.chunkshape, shapes.blockshape, NULL, 0, NULL, 0);
+
+  /* Create original data */
+  int64_t buffersize = typesize;
+  for (int i = 0; i < shapes.ndim; ++i) {
+    buffersize *= shapes.shape[i];
+  }
+
+  /* Create b2nd_array_t with original data */
+  b2nd_array_t *src;
+  B2ND_TEST_ASSERT(b2nd_nans(ctx, &src));
+
+  /* Fill dest array with b2nd_array_t data */
+  uint8_t *buffer_dest = malloc(buffersize);
+  B2ND_TEST_ASSERT(b2nd_to_cbuffer(src, buffer_dest, buffersize));
+
+  /* Testing */
+  for (int i = 0; i < buffersize / typesize; ++i) {
+    bool is_true = false;
+    switch (typesize) {
+      case 8:
+        is_true = isnan(((double *) buffer_dest)[i]);
+        break;
+      case 4:
+        is_true = isnan(((float *) buffer_dest)[i]);
+        break;
+      default:
+        break;
+    }
+    CUTEST_ASSERT("Elements are not equals", is_true);
+  }
+
+  /* Free mallocs */
+  free(buffer_dest);
+  B2ND_TEST_ASSERT(b2nd_free(src));
+  B2ND_TEST_ASSERT(b2nd_free_ctx(ctx));
+  blosc2_remove_urlpath(urlpath);
+
+  return BLOSC2_ERROR_SUCCESS;
+}
+
+
+CUTEST_TEST_TEARDOWN(nans) {
+  blosc2_destroy();
+}
+
+int main() {
+  CUTEST_TEST_RUN(nans);
+}