re-introduce ndarray_get_buffer, and buffer protocol

Author: v923z

code/ndarray.c

@@ -2026,3 +2026,15 @@ mp_obj_t ndarray_info(mp_obj_t obj_in) {
 
 MP_DEFINE_CONST_FUN_OBJ_1(ndarray_info_obj, ndarray_info);
 #endif
+
+// (the get_buffer protocol returns 0 for success, 1 for failure)
+mp_int_t ndarray_get_buffer(mp_obj_t self_in, mp_buffer_info_t *bufinfo, mp_uint_t flags) {
+    ndarray_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    if(!ndarray_is_dense(self)) {
+        return 1;
+    }
+    bufinfo->len = self->itemsize * self->len;
+    bufinfo->buf = self->array;
+    bufinfo->typecode = self->dtype;
+    return 0;
+}

code/ndarray.h

@@ -181,6 +181,7 @@ mp_obj_t ndarray_info(mp_obj_t );
 MP_DECLARE_CONST_FUN_OBJ_1(ndarray_info_obj);
 #endif
 
+mp_int_t ndarray_get_buffer(mp_obj_t , mp_buffer_info_t *, mp_uint_t );
 //void ndarray_attributes(mp_obj_t , qstr , mp_obj_t *);
 
 ndarray_obj_t *ndarray_from_mp_obj(mp_obj_t );

code/ulab.c

@@ -33,7 +33,7 @@
 
 #include "user/user.h"
 
-#define ULAB_VERSION 2.4.2
+#define ULAB_VERSION 2.4.3
 #define xstr(s) str(s)
 #define str(s) #s
 #define ULAB_VERSION_STRING xstr(ULAB_VERSION) xstr(-) xstr(ULAB_MAX_DIMS) xstr(D)
@@ -105,6 +105,7 @@ const mp_obj_type_t ulab_ndarray_type = {
     #if NDARRAY_HAS_BINARY_OPS
     .binary_op = ndarray_binary_op,
     #endif
+    .buffer_p = { .get_buffer = ndarray_get_buffer, },
     .locals_dict = (mp_obj_dict_t*)&ulab_ndarray_locals_dict,
 };
 

docs/ulab-change-log.md

@@ -1,5 +1,11 @@
 Sun, 21 Feb 2021
 
+version 2.4.3
+
+    re-introduce ndarray_get_buffer, and buffer protocol
+
+Sun, 21 Feb 2021
+
 version 2.4.2
 
     fix ndarray_is_dense, eye, ones, full, and zeros for Boolean type