Wrap new rolling window utility function in pylibcudf

python/cudf/cudf/_lib/pylibcudf/libcudf/CMakeLists.txt

@@ -13,7 +13,7 @@
 # =============================================================================
 
 set(cython_sources aggregation.pyx binaryop.pyx copying.pyx expressions.pyx reduce.pyx replace.pyx
-                   round.pyx stream_compaction.pyx types.pyx unary.pyx
+                   rolling.pyx round.pyx stream_compaction.pyx types.pyx unary.pyx
 )
 
 set(linked_libraries cudf::cudf)

python/cudf/cudf/_lib/pylibcudf/libcudf/rolling.pxd

@@ -1,16 +1,26 @@
 # Copyright (c) 2020-2024, NVIDIA CORPORATION.
 
+from libc.stdint cimport int32_t
+from libcpp cimport bool
 from libcpp.memory cimport unique_ptr
+from libcpp.utility cimport pair
 
 from cudf._lib.types import cudf_to_np_types, np_to_cudf_types
 
 from cudf._lib.pylibcudf.libcudf.aggregation cimport rolling_aggregation
 from cudf._lib.pylibcudf.libcudf.column.column cimport column
 from cudf._lib.pylibcudf.libcudf.column.column_view cimport column_view
+from cudf._lib.pylibcudf.libcudf.scalar.scalar cimport scalar
 from cudf._lib.pylibcudf.libcudf.types cimport size_type
 
 
 cdef extern from "cudf/rolling.hpp" namespace "cudf" nogil:
+    cpdef enum class window_type(int32_t):
+        LEFT_CLOSED
+        RIGHT_CLOSED
+        CLOSED
+        OPEN
+
     cdef unique_ptr[column] rolling_window(
         column_view source,
         column_view preceding_window,
@@ -24,3 +34,10 @@ cdef extern from "cudf/rolling.hpp" namespace "cudf" nogil:
         size_type following_window,
         size_type min_periods,
         rolling_aggregation& agg) except +
+
+    cdef pair[unique_ptr[column], unique_ptr[column]] windows_from_offset(
+        column_view input,
+        scalar length,
+        scalar offset,
+        window_type,
+        bool) except +

python/cudf/cudf/_lib/pylibcudf/rolling.pxd

@@ -1,19 +1,31 @@
 # Copyright (c) 2024, NVIDIA CORPORATION.
+from libc.stdint cimport int32_t
+from libcpp cimport bool
 
+from cudf._lib.pylibcudf.libcudf.rolling cimport window_type
 from cudf._lib.pylibcudf.libcudf.types cimport size_type
 
 from .aggregation cimport Aggregation
 from .column cimport Column
+from .scalar cimport Scalar
 
-ctypedef fused WindowType:
+ctypedef fused WindowArg:
     Column
     size_type
 
 
 cpdef Column rolling_window(
     Column source,
-    WindowType preceding_window,
-    WindowType following_window,
+    WindowArg preceding_window,
+    WindowArg following_window,
     size_type min_periods,
     Aggregation agg,
 )
+
+cpdef tuple[Column, Column] windows_from_offset(
+    Column input,
+    Scalar length,
+    Scalar offset,
+    window_type window_type,
+    bool only_preceding,
+)

python/cudf/cudf/_lib/pylibcudf/rolling.pyx

@@ -1,22 +1,27 @@
 # Copyright (c) 2024, NVIDIA CORPORATION.
 
 from cython.operator cimport dereference
+from libcpp cimport bool
 from libcpp.memory cimport unique_ptr
-from libcpp.utility cimport move
+from libcpp.utility cimport move, pair
 
 from cudf._lib.pylibcudf.libcudf cimport rolling as cpp_rolling
 from cudf._lib.pylibcudf.libcudf.aggregation cimport rolling_aggregation
 from cudf._lib.pylibcudf.libcudf.column.column cimport column
+from cudf._lib.pylibcudf.libcudf.rolling cimport window_type
 from cudf._lib.pylibcudf.libcudf.types cimport size_type
 
 from .aggregation cimport Aggregation
 from .column cimport Column
+from .scalar cimport Scalar
+
+from cudf._lib.pylibcudf.libcudf.rolling import window_type as WindowType  # no-cython-lint, isort: skip
 
 
 cpdef Column rolling_window(
     Column source,
-    WindowType preceding_window,
-    WindowType following_window,
+    WindowArg preceding_window,
+    WindowArg following_window,
     size_type min_periods,
     Aggregation agg,
 ):
@@ -48,7 +53,7 @@ cpdef Column rolling_window(
     # TODO: Consider making all the conversion functions nogil functions that
     # reclaim the GIL internally for just the necessary scope like column.view()
     cdef const rolling_aggregation *c_agg = agg.view_underlying_as_rolling()
-    if WindowType is Column:
+    if WindowArg is Column:
         with nogil:
             result = move(
                 cpp_rolling.rolling_window(
@@ -71,3 +76,28 @@ cpdef Column rolling_window(
                 )
             )
     return Column.from_libcudf(move(result))
+
+
+cpdef tuple[Column, Column] windows_from_offset(
+    Column input,
+    Scalar length,
+    Scalar offset,
+    window_type typ,
+    bool only_preceding,
+):
+    cdef pair[unique_ptr[column], unique_ptr[column]] result
+    with nogil:
+        result = cpp_rolling.windows_from_offset(
+                input.view(),
+                dereference(length.c_obj),
+                dereference(offset.c_obj),
+                typ,
+                only_preceding,
+            )
+    if only_preceding:
+        return (Column.from_libcudf(move(result.first)), None)
+    else:
+        return (
+            Column.from_libcudf(move(result.first)),
+            Column.from_libcudf(move(result.second)),
+        )