implemented BlockIndex.sizeof

Author: flexatone

src/_arraykit.c

@@ -4812,6 +4812,14 @@ BlockIndex_length(BlockIndexObject *self){
 }
 
 
+static PyObject *
+BlockIndex_sizeof(BlockIndexObject *self) {
+    return PyLong_FromSsize_t(
+        Py_TYPE(self)->tp_basicsize
+        + (self->bir_capacity) * sizeof(BlockIndexRecord)
+    );
+}
+
 
 // Given an index, return just the block index.
 static PyObject*
@@ -4864,6 +4872,7 @@ static PyMethodDef BlockIndex_methods[] = {
     {"register", (PyCFunction)BlockIndex_register, METH_O, NULL},
     {"__getstate__", (PyCFunction) BlockIndex_getstate, METH_NOARGS, NULL},
     {"__setstate__", (PyCFunction) BlockIndex_setstate, METH_O, NULL},
+    {"__sizeof__", (PyCFunction) BlockIndex_sizeof, METH_NOARGS, NULL},
     {"to_list", (PyCFunction)BlockIndex_to_list, METH_NOARGS, NULL},
     {"to_bytes", (PyCFunction)BlockIndex_to_bytes, METH_NOARGS, NULL},
     {"copy", (PyCFunction)BlockIndex_copy, METH_NOARGS, NULL},

test/test_block_index.py

@@ -141,6 +141,15 @@ def test_block_index_copy_b(self) -> None:
         del bi2
         self.assertEqual(dt2, np.dtype(np.float64))
 
+
+    #---------------------------------------------------------------------------
+    def test_block_index_sizeof_a(self) -> None:
+        bi1 = BlockIndex()
+        so1 = sys.getsizeof(bi1)
+        bi1.register(np.arange(100).reshape(2,50))
+        so2 = sys.getsizeof(bi1)
+        self.assertTrue(so1 < so2)
+
     #---------------------------------------------------------------------------
 
     def test_block_index_len_a(self) -> None: