From f117d0395173de8abf684c08f2a16432c302982f Mon Sep 17 00:00:00 2001
From: galipremsagar <sagarprem75@gmail.com>
Date: Mon, 31 Oct 2022 16:27:01 -0700
Subject: [PATCH 1/3] add StructColumn.memory_usage

---
 python/cudf/cudf/core/column/struct.py | 13 +++++++++++++
 python/cudf/cudf/core/dtypes.py        |  7 +++++++
 python/cudf/cudf/tests/test_list.py    |  2 ++
 python/cudf/cudf/tests/test_struct.py  | 15 +++++++++++++++
 4 files changed, 37 insertions(+)

diff --git a/python/cudf/cudf/core/column/struct.py b/python/cudf/cudf/core/column/struct.py
index 67ff3e48dbd..69d70cf427f 100644
--- a/python/cudf/cudf/core/column/struct.py
+++ b/python/cudf/cudf/core/column/struct.py
@@ -1,6 +1,8 @@
 # Copyright (c) 2020-2022, NVIDIA CORPORATION.
 from __future__ import annotations
 
+from functools import cached_property
+
 import pandas as pd
 import pyarrow as pa
 
@@ -65,6 +67,17 @@ def to_pandas(self, index: pd.Index = None, **kwargs) -> "pd.Series":
             pd_series.index = index
         return pd_series
 
+    @cached_property
+    def memory_usage(self):
+        n = 0
+        if self.nullable:
+            n += cudf._lib.null_mask.bitmask_allocation_size_bytes(self.size)
+
+        for child in self.children:
+            n += child.memory_usage
+
+        return n
+
     def element_indexing(self, index: int):
         result = super().element_indexing(index)
         return {
diff --git a/python/cudf/cudf/core/dtypes.py b/python/cudf/cudf/core/dtypes.py
index 84f528549e9..201dc253a98 100644
--- a/python/cudf/cudf/core/dtypes.py
+++ b/python/cudf/cudf/core/dtypes.py
@@ -627,6 +627,13 @@ def deserialize(cls, header: dict, frames: list):
                 fields[k] = pickle.loads(dtype)
         return cls(fields)
 
+    @property
+    def itemsize(self):
+        return sum(
+            cudf.utils.dtypes.cudf_dtype_from_pa_type(field.type).itemsize
+            for field in self._typ
+        )
+
 
 decimal_dtype_template = textwrap.dedent(
     """
diff --git a/python/cudf/cudf/tests/test_list.py b/python/cudf/cudf/tests/test_list.py
index 8ea11382419..4c2a14fc45c 100644
--- a/python/cudf/cudf/tests/test_list.py
+++ b/python/cudf/cudf/tests/test_list.py
@@ -864,6 +864,8 @@ def test_memory_usage():
     assert s1.memory_usage() == 44
     s2 = cudf.Series([[[[1, 2]]], [[[3, 4]]]])
     assert s2.memory_usage() == 68
+    s3 = cudf.Series([[{"b": 1, "a": 10}, {"b": 2, "a": 100}]])
+    assert s3.memory_usage() == 40
 
 
 @pytest.mark.parametrize(
diff --git a/python/cudf/cudf/tests/test_struct.py b/python/cudf/cudf/tests/test_struct.py
index 4c70d20c488..95e02702a5a 100644
--- a/python/cudf/cudf/tests/test_struct.py
+++ b/python/cudf/cudf/tests/test_struct.py
@@ -371,3 +371,18 @@ def test_nested_struct_extract_host_scalars(data, idx, expected):
     series = cudf.Series(data)
 
     assert _nested_na_replace(series[idx]) == _nested_na_replace(expected)
+
+
+def test_struct_memory_usage():
+    s = cudf.Series([{"a": 1, "b": 10}, {"a": 2, "b": 20}, {"a": 3, "b": 30}])
+    df = s.struct.explode()
+
+    assert_eq(s.memory_usage(), df.memory_usage().sum())
+
+
+def test_struct_with_null_memory_usage():
+    s = cudf.Series(
+        [{"a": 1, "b": 10}, {"a": 2, "b": 20}, None, None, {"a": 3, "b": 30}]
+    )
+
+    assert s.memory_usage() == 272

From 1a07b9204c4cccdd4951b02bc0a3740546d4d6a5 Mon Sep 17 00:00:00 2001
From: galipremsagar <sagarprem75@gmail.com>
Date: Tue, 1 Nov 2022 05:34:08 -0700
Subject: [PATCH 2/3] address reviews

---
 python/cudf/cudf/core/dtypes.py       | 3 ++-
 python/cudf/cudf/tests/test_struct.py | 9 +++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/python/cudf/cudf/core/dtypes.py b/python/cudf/cudf/core/dtypes.py
index 201dc253a98..a56de0cd451 100644
--- a/python/cudf/cudf/core/dtypes.py
+++ b/python/cudf/cudf/core/dtypes.py
@@ -4,6 +4,7 @@
 import operator
 import pickle
 import textwrap
+from functools import cached_property
 from typing import Any, Callable, Dict, List, Tuple, Type, Union
 
 import numpy as np
@@ -627,7 +628,7 @@ def deserialize(cls, header: dict, frames: list):
                 fields[k] = pickle.loads(dtype)
         return cls(fields)
 
-    @property
+    @cached_property
     def itemsize(self):
         return sum(
             cudf.utils.dtypes.cudf_dtype_from_pa_type(field.type).itemsize
diff --git a/python/cudf/cudf/tests/test_struct.py b/python/cudf/cudf/tests/test_struct.py
index 95e02702a5a..64dcec60d73 100644
--- a/python/cudf/cudf/tests/test_struct.py
+++ b/python/cudf/cudf/tests/test_struct.py
@@ -381,8 +381,13 @@ def test_struct_memory_usage():
 
 
 def test_struct_with_null_memory_usage():
-    s = cudf.Series(
-        [{"a": 1, "b": 10}, {"a": 2, "b": 20}, None, None, {"a": 3, "b": 30}]
+    df = cudf.DataFrame(
+        {
+            "a": cudf.Series([1, 2, -1, -1, 3], dtype="int64"),
+            "b": cudf.Series([10, 20, -1, -1, 30], dtype="int64"),
+        }
     )
+    s = df.to_struct()
+    s[2:4] = None
 
     assert s.memory_usage() == 272

From 668c842bfcf3f935398fc34ee07e25a952c9c756 Mon Sep 17 00:00:00 2001
From: galipremsagar <sagarprem75@gmail.com>
Date: Tue, 1 Nov 2022 05:38:23 -0700
Subject: [PATCH 3/3] add before and after null mask

---
 python/cudf/cudf/tests/test_struct.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/python/cudf/cudf/tests/test_struct.py b/python/cudf/cudf/tests/test_struct.py
index 64dcec60d73..eaee1efcbc8 100644
--- a/python/cudf/cudf/tests/test_struct.py
+++ b/python/cudf/cudf/tests/test_struct.py
@@ -388,6 +388,7 @@ def test_struct_with_null_memory_usage():
         }
     )
     s = df.to_struct()
-    s[2:4] = None
+    assert s.memory_usage() == 80
 
+    s[2:4] = None
     assert s.memory_usage() == 272