Deprecate strings_column_view::offsets_begin() (#15205)

Deprecates the `cudf::strings_column_view::offsets_begin()` and `cudf::strings_column_view::offsets_end()` since they are hardcoded to return `size_type*`. There are very few places that used these functions.

Authors:
  - David Wendt (https://github.com/davidwendt)

Approvers:
  - Mark Harris (https://github.com/harrism)
  - Bradley Dice (https://github.com/bdice)
  - Nghia Truong (https://github.com/ttnghia)

URL: #15205

cpp/include/cudf/strings/strings_column_view.hpp

@@ -88,20 +88,24 @@ class strings_column_view : private column_view {
   /**
    * @brief Return an iterator for the offsets child column.
    *
+   * @deprecated Since 24.04
+   *
    * This automatically applies the offset of the parent.
    *
    * @return Iterator pointing to the first offset value.
    */
-  [[nodiscard]] offset_iterator offsets_begin() const;
+  [[deprecated]] offset_iterator offsets_begin() const;
 
   /**
    * @brief Return an end iterator for the offsets child column.
    *
+   * @deprecated Since 24.04
+   *
    * This automatically applies the offset of the parent.
    *
    * @return Iterator pointing 1 past the last offset value.
    */
-  [[nodiscard]] offset_iterator offsets_end() const;
+  [[deprecated]] offset_iterator offsets_end() const;
 
   /**
    * @brief Returns the number of bytes in the chars child column.

cpp/src/strings/replace/multi.cu

@@ -302,17 +302,16 @@ std::unique_ptr<column> replace_character_parallel(strings_column_view const& in
     auto string_indices = rmm::device_uvector<size_type>(target_count, stream);
 
     auto const pos_itr = cudf::detail::make_counting_transform_iterator(
-      0, cuda::proclaim_return_type<size_type>([d_positions] __device__(auto idx) -> size_type {
+      0, cuda::proclaim_return_type<int64_t>([d_positions] __device__(auto idx) -> int64_t {
         return d_positions[idx].first;
       }));
     auto pos_count = std::distance(d_positions, copy_end);
 
-    thrust::upper_bound(rmm::exec_policy(stream),
-                        input.offsets_begin(),
-                        input.offsets_end(),
-                        pos_itr,
-                        pos_itr + pos_count,
-                        string_indices.begin());
+    auto begin =
+      cudf::detail::offsetalator_factory::make_input_iterator(input.offsets(), input.offset());
+    auto end = begin + input.offsets().size();
+    thrust::upper_bound(
+      rmm::exec_policy(stream), begin, end, pos_itr, pos_itr + pos_count, string_indices.begin());
 
     // compute offsets per string
     auto targets_offsets   = rmm::device_uvector<size_type>(strings_count + 1, stream);

cpp/src/strings/replace/replace.cu

@@ -413,10 +413,10 @@ std::unique_ptr<column> replace_char_parallel(strings_column_view const& strings
 {
   auto const strings_count = strings.size();
   auto const offset_count  = strings_count + 1;
-  auto const d_offsets     = strings.offsets_begin();
-  auto const d_in_chars    = strings.chars_begin(stream);
-  auto const chars_bytes   = chars_end - chars_start;
-  auto const target_size   = d_target.size_bytes();
+  auto const d_offsets   = strings.offsets().begin<int32_t>() + strings.offset();  // TODO: PR 14824
+  auto const d_in_chars  = strings.chars_begin(stream);
+  auto const chars_bytes = chars_end - chars_start;
+  auto const target_size = d_target.size_bytes();
 
   // detect a target match at the specified byte position
   device_span<char const> const d_chars_span(d_in_chars, chars_end);

cpp/src/strings/strings_column_view.cpp

@@ -37,12 +37,12 @@ column_view strings_column_view::offsets() const
 
 strings_column_view::offset_iterator strings_column_view::offsets_begin() const
 {
-  return offsets().begin<size_type>() + offset();
+  return offsets().begin<int32_t>() + offset();
 }
 
 strings_column_view::offset_iterator strings_column_view::offsets_end() const
 {
-  return offsets_begin() + size() + 1;
+  return offsets().begin<int32_t>() + offset() + size() + 1;
 }
 
 int64_t strings_column_view::chars_size(rmm::cuda_stream_view stream) const noexcept

cpp/tests/strings/array_tests.cpp

@@ -213,19 +213,4 @@ TEST_F(StringsColumnTest, ScatterZeroSizeStringsColumn)
   cudf::test::expect_column_empty(results->view().column(0));
 }
 
-TEST_F(StringsColumnTest, OffsetsBeginEnd)
-{
-  cudf::test::strings_column_wrapper input({"eee", "bb", "", "", "aa", "bbb", "ééé"},
-                                           {1, 1, 0, 1, 1, 1, 1});
-
-  cudf::test::fixed_width_column_wrapper<int32_t> expected({0, 5});
-  auto scv = cudf::strings_column_view(input);
-  EXPECT_EQ(std::distance(scv.offsets_begin(), scv.offsets_end()),
-            static_cast<std::ptrdiff_t>(scv.size() + 1));
-
-  scv = cudf::strings_column_view(cudf::slice(input, {1, 5}).front());
-  EXPECT_EQ(std::distance(scv.offsets_begin(), scv.offsets_end()),
-            static_cast<std::ptrdiff_t>(scv.size() + 1));
-}
-
 CUDF_TEST_PROGRAM_MAIN()