address issue raised in #676 (#677)

* ndarrays can be created from buffer

Author: v923z

code/ndarray.c

@@ -6,7 +6,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2019-2022 Zoltán Vörös
+ * Copyright (c) 2019-2024 Zoltán Vörös
  *               2020 Jeff Epler for Adafruit Industries
  *               2020 Taku Fukada
 */
@@ -509,8 +509,9 @@ static size_t multiply_size(size_t a, size_t b) {
     return result;
 }
 
-ndarray_obj_t *ndarray_new_ndarray(uint8_t ndim, size_t *shape, int32_t *strides, uint8_t dtype) {
+ndarray_obj_t *ndarray_new_ndarray(uint8_t ndim, size_t *shape, int32_t *strides, uint8_t dtype, uint8_t *buffer) {
     // Creates the base ndarray with shape, and initialises the values to straight 0s
+    // optionally, values can be supplied via the last argument
     ndarray_obj_t *ndarray = m_new_obj(ndarray_obj_t);
     ndarray->base.type = &ulab_ndarray_type;
     ndarray->dtype = dtype == NDARRAY_BOOL ? NDARRAY_UINT8 : dtype;
@@ -536,9 +537,13 @@ ndarray_obj_t *ndarray_new_ndarray(uint8_t ndim, size_t *shape, int32_t *strides
 
     // if the length is 0, still allocate a single item, so that contractions can be handled
     size_t len = multiply_size(ndarray->itemsize, MAX(1, ndarray->len));
-    uint8_t *array = m_new0(byte, len);
-    // this should set all elements to 0, irrespective of the of the dtype (all bits are zero)
-    // we could, perhaps, leave this step out, and initialise the array only, when needed
+    uint8_t *array;
+    array = buffer;
+    if(array == NULL) {
+        // this should set all elements to 0, irrespective of the of the dtype (all bits are zero)
+        // we could, perhaps, leave this step out, and initialise the array only, when needed
+        array = m_new0(byte, len);
+    }
     ndarray->array = array;
     ndarray->origin = array;
     return ndarray;
@@ -547,12 +552,12 @@ ndarray_obj_t *ndarray_new_ndarray(uint8_t ndim, size_t *shape, int32_t *strides
 ndarray_obj_t *ndarray_new_dense_ndarray(uint8_t ndim, size_t *shape, uint8_t dtype) {
     // creates a dense array, i.e., one, where the strides are derived directly from the shapes
     // the function should work in the general n-dimensional case
-    int32_t *strides = m_new(int32_t, ULAB_MAX_DIMS);
-    strides[ULAB_MAX_DIMS-1] = (int32_t)ulab_binary_get_size(dtype);
-    for(size_t i=ULAB_MAX_DIMS; i > 1; i--) {
-        strides[i-2] = strides[i-1] * MAX(1, shape[i-1]);
-    }
-    return ndarray_new_ndarray(ndim, shape, strides, dtype);
+    // int32_t *strides = m_new(int32_t, ULAB_MAX_DIMS);
+    // strides[ULAB_MAX_DIMS - 1] = (int32_t)ulab_binary_get_size(dtype);
+    // for(size_t i = ULAB_MAX_DIMS; i > 1; i--) {
+    //     strides[i-2] = strides[i-1] * MAX(1, shape[i-1]);
+    // }
+    return ndarray_new_ndarray(ndim, shape, NULL, dtype, NULL);
 }
 
 ndarray_obj_t *ndarray_new_ndarray_from_tuple(mp_obj_tuple_t *_shape, uint8_t dtype) {
@@ -650,7 +655,7 @@ ndarray_obj_t *ndarray_copy_view(ndarray_obj_t *source) {
     if(source->boolean) {
         dtype = NDARRAY_BOOL;
     }
-    ndarray_obj_t *ndarray = ndarray_new_ndarray(source->ndim, source->shape, strides, dtype);
+    ndarray_obj_t *ndarray = ndarray_new_ndarray(source->ndim, source->shape, strides, dtype, NULL);
     ndarray_copy_array(source, ndarray, 0);
     return ndarray;
 }
@@ -1884,7 +1889,7 @@ mp_obj_t ndarray_unary_op(mp_unary_op_t op, mp_obj_t self_in) {
             #if ULAB_SUPPORTS_COMPLEX
             if(self->dtype == NDARRAY_COMPLEX) {
                 int32_t *strides = strides_from_shape(self->shape, NDARRAY_FLOAT);
-                ndarray_obj_t *target = ndarray_new_ndarray(self->ndim, self->shape, strides, NDARRAY_FLOAT);
+                ndarray_obj_t *target = ndarray_new_ndarray(self->ndim, self->shape, strides, NDARRAY_FLOAT, NULL);
                 ndarray = MP_OBJ_TO_PTR(carray_abs(self, target));
             } else {
             #endif

code/ndarray.h

@@ -188,7 +188,7 @@ int32_t *ndarray_contract_strides(ndarray_obj_t *, uint8_t );
 ndarray_obj_t *ndarray_from_iterable(mp_obj_t , uint8_t );
 ndarray_obj_t *ndarray_new_dense_ndarray(uint8_t , size_t *, uint8_t );
 ndarray_obj_t *ndarray_new_ndarray_from_tuple(mp_obj_tuple_t *, uint8_t );
-ndarray_obj_t *ndarray_new_ndarray(uint8_t , size_t *, int32_t *, uint8_t );
+ndarray_obj_t *ndarray_new_ndarray(uint8_t , size_t *, int32_t *, uint8_t , uint8_t *);
 ndarray_obj_t *ndarray_new_linear_array(size_t , uint8_t );
 ndarray_obj_t *ndarray_new_view(ndarray_obj_t *, uint8_t , size_t *, int32_t *, int32_t );
 bool ndarray_is_dense(ndarray_obj_t *);

code/numpy/create.c

@@ -838,19 +838,10 @@ mp_obj_t create_frombuffer(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw
                 len = count;
             }
         }
-        ndarray_obj_t *ndarray = m_new_obj(ndarray_obj_t);
-        ndarray->base.type = &ulab_ndarray_type;
-        ndarray->dtype = dtype == NDARRAY_BOOL ? NDARRAY_UINT8 : dtype;
-        ndarray->boolean = dtype == NDARRAY_BOOL ? NDARRAY_BOOLEAN : NDARRAY_NUMERIC;
-        ndarray->ndim = 1;
-        ndarray->len = len;
-        ndarray->itemsize = sz;
-        ndarray->shape[ULAB_MAX_DIMS - 1] = len;
-        ndarray->strides[ULAB_MAX_DIMS - 1] = sz;
 
+        size_t *shape = ndarray_shape_vector(0, 0, 0, len);
         uint8_t *buffer = bufinfo.buf;
-        ndarray->array = buffer + offset;
-        return MP_OBJ_FROM_PTR(ndarray);
+        return ndarray_new_ndarray(1, shape, NULL, dtype, buffer + offset);
     }
     return mp_const_none;
 }

code/numpy/numerical.c

@@ -746,7 +746,7 @@ mp_obj_t numerical_argsort(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw
     numerical_reduce_axes(ndarray, ax, shape, strides);
 
     // We could return an NDARRAY_UINT8 array, if all lengths are shorter than 256
-    ndarray_obj_t *indices = ndarray_new_ndarray(ndarray->ndim, ndarray->shape, NULL, NDARRAY_UINT16);
+    ndarray_obj_t *indices = ndarray_new_ndarray(ndarray->ndim, ndarray->shape, NULL, NDARRAY_UINT16, NULL);
     int32_t *istrides = m_new0(int32_t, ULAB_MAX_DIMS);
     numerical_reduce_axes(indices, ax, shape, istrides);
 

code/ulab.c

@@ -33,7 +33,7 @@
 #include "user/user.h"
 #include "utils/utils.h"
 
-#define ULAB_VERSION 6.5.2
+#define ULAB_VERSION 6.5.3
 #define xstr(s) str(s)
 #define str(s) #s