Fix calls to deprecated strings factory API

cpp/benchmarks/common/generate_input.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -540,7 +540,7 @@ std::unique_ptr<cudf::column> create_random_utf8_string_column(data_profile cons
   return cudf::make_strings_column(
     num_rows,
     std::make_unique<cudf::column>(std::move(offsets), rmm::device_buffer{}, 0),
-    std::make_unique<cudf::column>(std::move(chars), rmm::device_buffer{}, 0),
+    chars.release(),
     null_count,
     profile.get_null_probability().has_value() ? std::move(result_bitmask) : rmm::device_buffer{});
 }

cpp/benchmarks/json/json.cu

@@ -177,10 +177,10 @@ auto build_json_string_column(int desired_bytes, int num_rows)
   auto d_store_order = cudf::column_device_view::create(float_2bool_columns->get_column(2));
   json_benchmark_row_builder jb{
     desired_bytes, num_rows, {*d_books, *d_bicycles}, *d_book_pct, *d_misc_order, *d_store_order};
-  auto children = cudf::strings::detail::make_strings_children(
+  auto [offsets, chars] = cudf::strings::detail::make_strings_children(
     jb, num_rows, cudf::get_default_stream(), rmm::mr::get_current_device_resource());
   return cudf::make_strings_column(
-    num_rows, std::move(children.first), std::move(children.second), 0, {});
+    num_rows, std::move(offsets), std::move(chars->release().data.release()[0]), 0, {});
 }
 
 void BM_case(benchmark::State& state, std::string query_arg)

cpp/include/cudf/strings/detail/copy_if_else.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -109,7 +109,7 @@ std::unique_ptr<cudf::column> copy_if_else(StringIterLeft lhs_begin,
 
   return make_strings_column(strings_count,
                              std::move(offsets_column),
-                             std::move(chars_column),
+                             std::move(chars_column->release().data.release()[0]),
                              null_count,
                              std::move(null_mask));
 }

cpp/include/cudf/strings/detail/copy_range.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -205,7 +205,7 @@ std::unique_ptr<column> copy_range(SourceValueIterator source_value_begin,
 
     return make_strings_column(target.size(),
                                std::move(p_offsets_column),
-                               std::move(p_chars_column),
+                               std::move(p_chars_column->release().data.release()[0]),
                                null_count,
                                std::move(null_mask));
   }

cpp/include/cudf/strings/detail/gather.cuh

@@ -321,7 +321,7 @@ std::unique_ptr<cudf::column> gather(strings_column_view const& strings,
 
   return make_strings_column(output_count,
                              std::move(out_offsets_column),
-                             std::move(out_chars_column),
+                             std::move(out_chars_column->release().data.release()[0]),
                              0,  // caller sets these
                              rmm::device_buffer{});
 }

cpp/include/cudf/strings/detail/merge.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -89,9 +89,8 @@ std::unique_ptr<column> merge(strings_column_view const& lhs,
   auto d_offsets = offsets_column->view().template data<int32_t>();
 
   // create the chars column
-  auto chars_column = strings::detail::create_chars_child_column(bytes, stream, mr);
-  // merge the strings
-  auto d_chars = chars_column->mutable_view().template data<char>();
+  rmm::device_uvector<char> chars(bytes, stream, mr);
+  auto d_chars = chars.data();
   thrust::for_each_n(rmm::exec_policy(stream),
                      thrust::make_counting_iterator<size_type>(0),
                      strings_count,
@@ -103,11 +102,8 @@ std::unique_ptr<column> merge(strings_column_view const& lhs,
                        memcpy(d_chars + d_offsets[idx], d_str.data(), d_str.size_bytes());
                      });
 
-  return make_strings_column(strings_count,
-                             std::move(offsets_column),
-                             std::move(chars_column),
-                             null_count,
-                             std::move(null_mask));
+  return make_strings_column(
+    strings_count, std::move(offsets_column), chars.release(), null_count, std::move(null_mask));
 }
 
 }  // namespace detail

cpp/include/cudf/strings/detail/strings_column_factories.cuh

@@ -137,7 +137,7 @@ std::unique_ptr<column> make_strings_column(IndexPairIterator begin,
 
   return make_strings_column(strings_count,
                              std::move(offsets_column),
-                             std::move(chars_column),
+                             std::move(chars_column->release().data.release()[0]),
                              null_count,
                              std::move(null_mask));
 }
@@ -187,13 +187,12 @@ std::unique_ptr<column> make_strings_column(CharIterator chars_begin,
                       [] __device__(auto offset) { return static_cast<int32_t>(offset); }));
 
   // build chars column
-  auto chars_column = strings::detail::create_chars_child_column(bytes, stream, mr);
-  auto chars_view   = chars_column->mutable_view();
-  thrust::copy(rmm::exec_policy(stream), chars_begin, chars_end, chars_view.data<char>());
+  rmm::device_uvector<char> chars_data(bytes, stream, mr);
+  thrust::copy(rmm::exec_policy(stream), chars_begin, chars_end, chars_data.begin());
 
   return make_strings_column(strings_count,
                              std::move(offsets_column),
-                             std::move(chars_column),
+                             chars_data.release(),
                              null_count,
                              std::move(null_mask));
 }

cpp/include/cudf_test/column_wrapper.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -757,20 +757,21 @@ class strings_column_wrapper : public detail::column_wrapper {
   strings_column_wrapper(StringsIterator begin, StringsIterator end) : column_wrapper{}
   {
     size_type num_strings = std::distance(begin, end);
+    if (num_strings == 0) {
+      wrapped = cudf::make_empty_column(cudf::type_id::STRING);
+      return;
+    }
     auto all_valid        = thrust::make_constant_iterator(true);
     auto [chars, offsets] = detail::make_chars_and_offsets(begin, end, all_valid);
-    auto d_chars          = std::make_unique<cudf::column>(
-      cudf::detail::make_device_uvector_sync(
-        chars, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource()),
-      rmm::device_buffer{},
-      0);
+    auto d_chars          = cudf::detail::make_device_uvector_async(
+      chars, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource());
     auto d_offsets = std::make_unique<cudf::column>(
       cudf::detail::make_device_uvector_sync(
         offsets, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource()),
       rmm::device_buffer{},
       0);
     wrapped =
-      cudf::make_strings_column(num_strings, std::move(d_offsets), std::move(d_chars), 0, {});
+      cudf::make_strings_column(num_strings, std::move(d_offsets), d_chars.release(), 0, {});
   }
 
   /**
@@ -805,23 +806,24 @@ class strings_column_wrapper : public detail::column_wrapper {
   strings_column_wrapper(StringsIterator begin, StringsIterator end, ValidityIterator v)
     : column_wrapper{}
   {
-    size_type num_strings        = std::distance(begin, end);
+    size_type num_strings = std::distance(begin, end);
+    if (num_strings == 0) {
+      wrapped = cudf::make_empty_column(cudf::type_id::STRING);
+      return;
+    }
     auto [chars, offsets]        = detail::make_chars_and_offsets(begin, end, v);
     auto [null_mask, null_count] = detail::make_null_mask_vector(v, v + num_strings);
-    auto d_chars                 = std::make_unique<cudf::column>(
-      cudf::detail::make_device_uvector_sync(
-        chars, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource()),
-      rmm::device_buffer{},
-      0);
+    auto d_chars                 = cudf::detail::make_device_uvector_async(
+      chars, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource());
     auto d_offsets = std::make_unique<cudf::column>(
-      cudf::detail::make_device_uvector_sync(
+      cudf::detail::make_device_uvector_async(
         offsets, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource()),
       rmm::device_buffer{},
       0);
     auto d_bitmask = cudf::detail::make_device_uvector_sync(
       null_mask, cudf::test::get_default_stream(), rmm::mr::get_current_device_resource());
     wrapped = cudf::make_strings_column(
-      num_strings, std::move(d_offsets), std::move(d_chars), null_count, d_bitmask.release());
+      num_strings, std::move(d_offsets), d_chars.release(), null_count, d_bitmask.release());
   }
 
   /**

cpp/src/hash/md5_hash.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -333,9 +333,8 @@ std::unique_ptr<column> md5(table_view const& input,
   auto [offsets_column, bytes] =
     cudf::detail::make_offsets_child_column(begin, begin + input.num_rows(), stream, mr);
 
-  auto chars_column = strings::detail::create_chars_child_column(bytes, stream, mr);
-  auto chars_view   = chars_column->mutable_view();
-  auto d_chars      = chars_view.data<char>();
+  rmm::device_uvector<char> chars(bytes, stream, mr);
+  auto d_chars = chars.data();
 
   auto const device_input = table_device_view::create(input, stream);
 
@@ -366,8 +365,7 @@ std::unique_ptr<column> md5(table_view const& input,
       }
     });
 
-  return make_strings_column(
-    input.num_rows(), std::move(offsets_column), std::move(chars_column), 0, {});
+  return make_strings_column(input.num_rows(), std::move(offsets_column), chars.release(), 0, {});
 }
 
 }  // namespace detail

cpp/src/interop/from_arrow.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -290,7 +290,7 @@ std::unique_ptr<column> dispatch_to_cudf_column::operator()<cudf::string_view>(
   auto const num_rows = offsets_column->size() - 1;
   auto out_col        = make_strings_column(num_rows,
                                      std::move(offsets_column),
-                                     std::move(chars_column),
+                                     std::move(chars_column->release().data.release()[0]),
                                      array.null_count(),
                                      std::move(*get_mask_buffer(array, stream, mr)));
 

cpp/src/io/csv/durations.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -202,7 +202,7 @@ struct dispatch_from_durations_fn {
     //
     return make_strings_column(strings_count,
                                std::move(offsets_column),
-                               std::move(chars_column),
+                               std::move(chars_column->release().data.release()[0]),
                                durations.null_count(),
                                std::move(null_mask));
   }

cpp/src/io/csv/writer_impl.cu

@@ -181,11 +181,12 @@ struct column_to_strings_fn {
 
     auto d_column = column_device_view::create(column_v, stream_);
     escape_strings_fn fn{*d_column, delimiter.value(stream_)};
-    auto children = cudf::strings::detail::make_strings_children(fn, column_v.size(), stream_, mr_);
+    auto [offsets_column, chars_column] =
+      cudf::strings::detail::make_strings_children(fn, column_v.size(), stream_, mr_);
 
     return make_strings_column(column_v.size(),
-                               std::move(children.first),
-                               std::move(children.second),
+                               std::move(offsets_column),
+                               std::move(chars_column->release().data.release()[0]),
                                column_v.null_count(),
                                cudf::detail::copy_bitmask(column_v, stream_, mr_));
   }

cpp/src/io/json/legacy/reader_impl.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -530,29 +530,27 @@ table_with_metadata convert_data_to_table(parse_options_view const& parse_opts,
   auto repl_chars   = std::vector<char>{'"', '\\', '\t', '\r', '\b'};
   auto repl_offsets = std::vector<size_type>{0, 1, 2, 3, 4, 5};
 
-  auto target = make_strings_column(
-    static_cast<size_type>(target_offsets.size() - 1),
-    std::make_unique<cudf::column>(
-      cudf::detail::make_device_uvector_async(
-        target_offsets, stream, rmm::mr::get_current_device_resource()),
-      rmm::device_buffer{},
-      0),
-    std::make_unique<cudf::column>(cudf::detail::make_device_uvector_async(
-                                     target_chars, stream, rmm::mr::get_current_device_resource()),
-                                   rmm::device_buffer{},
-                                   0),
-    0,
-    {});
+  auto target =
+    make_strings_column(static_cast<size_type>(target_offsets.size() - 1),
+                        std::make_unique<cudf::column>(
+                          cudf::detail::make_device_uvector_async(
+                            target_offsets, stream, rmm::mr::get_current_device_resource()),
+                          rmm::device_buffer{},
+                          0),
+                        cudf::detail::make_device_uvector_async(
+                          target_chars, stream, rmm::mr::get_current_device_resource())
+                          .release(),
+                        0,
+                        {});
   auto repl = make_strings_column(
     static_cast<size_type>(repl_offsets.size() - 1),
     std::make_unique<cudf::column>(cudf::detail::make_device_uvector_async(
                                      repl_offsets, stream, rmm::mr::get_current_device_resource()),
                                    rmm::device_buffer{},
                                    0),
-    std::make_unique<cudf::column>(cudf::detail::make_device_uvector_async(
-                                     repl_chars, stream, rmm::mr::get_current_device_resource()),
-                                   rmm::device_buffer{},
-                                   0),
+    cudf::detail::make_device_uvector_async(
+      repl_chars, stream, rmm::mr::get_current_device_resource())
+      .release(),
     0,
     {});
 

cpp/src/io/json/write_json.cu

@@ -170,12 +170,12 @@ struct escape_strings_fn {
                                               rmm::cuda_stream_view stream,
                                               rmm::mr::device_memory_resource* mr)
   {
-    auto children =
+    auto [offsets_column, chars_column] =
       cudf::strings::detail::make_strings_children(*this, column_v.size(), stream, mr);
 
     return make_strings_column(column_v.size(),
-                               std::move(children.first),
-                               std::move(children.second),
+                               std::move(offsets_column),
+                               std::move(chars_column->release().data.release()[0]),
                                column_v.null_count(),
                                cudf::detail::copy_bitmask(column_v, stream, mr));
   }
@@ -347,13 +347,11 @@ std::unique_ptr<column> struct_to_strings(table_view const& strings_columns,
                  d_strview_offsets + row_string_offsets.size(),
                  old_offsets.begin<size_type>(),
                  row_string_offsets.begin());
-  auto chars_data       = joined_col->release().data;
-  auto const chars_size = chars_data->size();
+  auto chars_data = joined_col->release().data;
   return make_strings_column(
     strings_columns.num_rows(),
     std::make_unique<cudf::column>(std::move(row_string_offsets), rmm::device_buffer{}, 0),
-    std::make_unique<cudf::column>(
-      data_type{type_id::INT8}, chars_size, std::move(*chars_data), rmm::device_buffer{}, 0),
+    std::move(chars_data.release()[0]),
     0,
     {});
 }
@@ -472,13 +470,11 @@ std::unique_ptr<column> join_list_of_strings(lists_column_view const& lists_stri
                  d_strview_offsets.end(),
                  old_offsets.begin<size_type>(),
                  row_string_offsets.begin());
-  auto chars_data       = joined_col->release().data;
-  auto const chars_size = chars_data->size();
+  auto chars_data = joined_col->release().data;
   return make_strings_column(
     num_lists,
     std::make_unique<cudf::column>(std::move(row_string_offsets), rmm::device_buffer{}, 0),
-    std::make_unique<cudf::column>(
-      data_type{type_id::INT8}, chars_size, std::move(*chars_data), rmm::device_buffer{}, 0),
+    std::move(chars_data.release()[0]),
     lists_strings.null_count(),
     cudf::detail::copy_bitmask(lists_strings.parent(), stream, mr));
 }
@@ -780,11 +776,7 @@ std::unique_ptr<column> make_strings_column_from_host(host_span<std::string cons
     rmm::device_buffer{},
     0);
   return cudf::make_strings_column(
-    host_strings.size(),
-    std::move(d_offsets),
-    std::make_unique<cudf::column>(std::move(d_chars), rmm::device_buffer{}, 0),
-    0,
-    {});
+    host_strings.size(), std::move(d_offsets), d_chars.release(), 0, {});
 }
 
 std::unique_ptr<column> make_column_names_column(host_span<column_name_info const> column_names,