MNT: move initialization of global ArrayMethods to module initialization

Author: ngoldbaum

numpy/_core/src/multiarray/convert_datatype.c

@@ -3236,31 +3236,20 @@ nonstructured_to_structured_get_loop(
     return 0;
 }
 
+// these are filled in during module initialization
+// we do not include these in the global data struct
+// to avoid the need to #include array_method.h for
+// all users of the global data struct
+static PyArrayMethodObject *VoidToGenericMethod = NULL;
+static PyArrayMethodObject *GenericToVoidMethod = NULL;
+static PyArrayMethodObject *ObjectToGenericMethod = NULL;
+static PyArrayMethodObject *GenericToObjectMethod = NULL;
 
 static PyObject *
 PyArray_GetGenericToVoidCastingImpl(void)
 {
-    static PyArrayMethodObject *method = NULL;
-
-    if (method != NULL) {
-        Py_INCREF(method);
-        return (PyObject *)method;
-    }
-
-    method = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
-    if (method == NULL) {
-        return PyErr_NoMemory();
-    }
-
-    method->name = "any_to_void_cast";
-    method->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
-    method->casting = -1;
-    method->resolve_descriptors = &nonstructured_to_structured_resolve_descriptors;
-    method->get_strided_loop = &nonstructured_to_structured_get_loop;
-    method->nin = 1;
-    method->nout = 1;
-
-    return (PyObject *)method;
+    Py_INCREF(GenericToVoidMethod);
+    return (PyObject *)GenericToVoidMethod;
 }
 
 
@@ -3397,27 +3386,8 @@ structured_to_nonstructured_get_loop(
 static PyObject *
 PyArray_GetVoidToGenericCastingImpl(void)
 {
-    static PyArrayMethodObject *method = NULL;
-
-    if (method != NULL) {
-        Py_INCREF(method);
-        return (PyObject *)method;
-    }
-
-    method = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
-    if (method == NULL) {
-        return PyErr_NoMemory();
-    }
-
-    method->name = "void_to_any_cast";
-    method->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
-    method->casting = -1;
-    method->resolve_descriptors = &structured_to_nonstructured_resolve_descriptors;
-    method->get_strided_loop = &structured_to_nonstructured_get_loop;
-    method->nin = 1;
-    method->nout = 1;
-
-    return (PyObject *)method;
+    Py_INCREF(VoidToGenericMethod);
+    return (PyObject *)VoidToGenericMethod;
 }
 
 
@@ -3781,31 +3751,11 @@ object_to_any_resolve_descriptors(
 static PyObject *
 PyArray_GetObjectToGenericCastingImpl(void)
 {
-    static PyArrayMethodObject *method = NULL;
-
-    if (method != NULL) {
-        Py_INCREF(method);
-        return (PyObject *)method;
-    }
-
-    method = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
-    if (method == NULL) {
-        return PyErr_NoMemory();
-    }
-
-    method->nin = 1;
-    method->nout = 1;
-    method->name = "object_to_any_cast";
-    method->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
-    method->casting = NPY_UNSAFE_CASTING;
-    method->resolve_descriptors = &object_to_any_resolve_descriptors;
-    method->get_strided_loop = &object_to_any_get_loop;
-
-    return (PyObject *)method;
+    Py_INCREF(ObjectToGenericMethod);
+    return (PyObject *)ObjectToGenericMethod;
 }
 
 
-
 /* Any object is simple (could even use the default) */
 static NPY_CASTING
 any_to_object_resolve_descriptors(
@@ -3838,27 +3788,8 @@ any_to_object_resolve_descriptors(
 static PyObject *
 PyArray_GetGenericToObjectCastingImpl(void)
 {
-    static PyArrayMethodObject *method = NULL;
-
-    if (method != NULL) {
-        Py_INCREF(method);
-        return (PyObject *)method;
-    }
-
-    method = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
-    if (method == NULL) {
-        return PyErr_NoMemory();
-    }
-
-    method->nin = 1;
-    method->nout = 1;
-    method->name = "any_to_object_cast";
-    method->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
-    method->casting = NPY_SAFE_CASTING;
-    method->resolve_descriptors = &any_to_object_resolve_descriptors;
-    method->get_strided_loop = &any_to_object_get_loop;
-
-    return (PyObject *)method;
+    Py_INCREF(GenericToObjectMethod);
+    return (PyObject *)GenericToObjectMethod;
 }
 
 
@@ -3910,6 +3841,68 @@ PyArray_InitializeObjectToObjectCast(void)
     return res;
 }
 
+static int
+initialize_void_and_object_globals(void) {
+    VoidToGenericMethod = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
+
+    if (VoidToGenericMethod == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    VoidToGenericMethod->name = "void_to_any_cast";
+    VoidToGenericMethod->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
+    VoidToGenericMethod->casting = -1;
+    VoidToGenericMethod->resolve_descriptors = &structured_to_nonstructured_resolve_descriptors;
+    VoidToGenericMethod->get_strided_loop = &structured_to_nonstructured_get_loop;
+    VoidToGenericMethod->nin = 1;
+    VoidToGenericMethod->nout = 1;
+
+    GenericToVoidMethod = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
+    if (GenericToVoidMethod == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    GenericToVoidMethod->name = "any_to_void_cast";
+    GenericToVoidMethod->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
+    GenericToVoidMethod->casting = -1;
+    GenericToVoidMethod->resolve_descriptors = &nonstructured_to_structured_resolve_descriptors;
+    GenericToVoidMethod->get_strided_loop = &nonstructured_to_structured_get_loop;
+    GenericToVoidMethod->nin = 1;
+    GenericToVoidMethod->nout = 1;
+
+    ObjectToGenericMethod = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
+    if (ObjectToGenericMethod == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    ObjectToGenericMethod->nin = 1;
+    ObjectToGenericMethod->nout = 1;
+    ObjectToGenericMethod->name = "object_to_any_cast";
+    ObjectToGenericMethod->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
+    ObjectToGenericMethod->casting = NPY_UNSAFE_CASTING;
+    ObjectToGenericMethod->resolve_descriptors = &object_to_any_resolve_descriptors;
+    ObjectToGenericMethod->get_strided_loop = &object_to_any_get_loop;
+
+    GenericToObjectMethod = PyObject_New(PyArrayMethodObject, &PyArrayMethod_Type);
+    if (GenericToObjectMethod == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    GenericToObjectMethod->nin = 1;
+    GenericToObjectMethod->nout = 1;
+    GenericToObjectMethod->name = "any_to_object_cast";
+    GenericToObjectMethod->flags = NPY_METH_SUPPORTS_UNALIGNED | NPY_METH_REQUIRES_PYAPI;
+    GenericToObjectMethod->casting = NPY_SAFE_CASTING;
+    GenericToObjectMethod->resolve_descriptors = &any_to_object_resolve_descriptors;
+    GenericToObjectMethod->get_strided_loop = &any_to_object_get_loop;
+
+    return 0;
+}
+
 
 NPY_NO_EXPORT int
 PyArray_InitializeCasts()
@@ -3930,5 +3923,10 @@ PyArray_InitializeCasts()
     if (PyArray_InitializeDatetimeCasts() < 0) {
         return -1;
     }
+
+    if (initialize_void_and_object_globals() < 0) {
+        return -1;
+    }
+
     return 0;
 }