Use experimental make_strings_children for json/csv writers (#15599)

Updates the JSON and CSV writer functions to use the new experimental make_strings_children.
Also included is an update to the JSON_BENCH benchmark for get_json_object.

Reference #15579

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

Approvers:
  - Karthikeyan (https://github.com/karthikeyann)
  - Bradley Dice (https://github.com/bdice)

URL: #15599

cpp/benchmarks/json/json.cu

@@ -22,7 +22,7 @@
 
 #include <cudf/column/column_factories.hpp>
 #include <cudf/json/json.hpp>
-#include <cudf/strings/detail/strings_children.cuh>
+#include <cudf/strings/detail/strings_children_ex.cuh>
 #include <cudf/strings/detail/utilities.cuh>
 #include <cudf/strings/string_view.hpp>
 #include <cudf/strings/strings_column_view.hpp>
@@ -77,8 +77,9 @@ struct json_benchmark_row_builder {
   cudf::column_device_view const d_book_pct;           // Book percentage
   cudf::column_device_view const d_misc_order;         // Misc-Store order
   cudf::column_device_view const d_store_order;        // Books-Bicycles order
-  int32_t* d_offsets{};
+  cudf::size_type* d_sizes{};
   char* d_chars{};
+  cudf::detail::input_offsetalator d_offsets;
   thrust::minstd_rand rng{5236};
   thrust::uniform_int_distribution<int> dist{};
 
@@ -155,7 +156,7 @@ struct json_benchmark_row_builder {
       output_str += Misc;
     }
     output_str += brace2;
-    if (!output_str.ptr) d_offsets[idx] = output_str.bytes;
+    if (!output_str.ptr) { d_sizes[idx] = output_str.bytes; }
   }
 };
 
@@ -177,7 +178,7 @@ 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 [offsets, chars] = cudf::strings::detail::make_strings_children(
+  auto [offsets, chars] = cudf::strings::detail::experimental::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(offsets), chars.release(), 0, {});
 }

cpp/src/io/csv/writer_impl.cu

@@ -33,7 +33,7 @@
 #include <cudf/strings/detail/combine.hpp>
 #include <cudf/strings/detail/converters.hpp>
 #include <cudf/strings/detail/replace.hpp>
-#include <cudf/strings/detail/strings_children.cuh>
+#include <cudf/strings/detail/strings_children_ex.cuh>
 #include <cudf/strings/strings_column_view.hpp>
 #include <cudf/table/table.hpp>
 #include <cudf/utilities/error.hpp>
@@ -75,8 +75,9 @@ namespace {
 struct escape_strings_fn {
   column_device_view const d_column;
   string_view const d_delimiter;  // check for column delimiter
-  size_type* d_offsets{};
+  size_type* d_sizes{};
   char* d_chars{};
+  cudf::detail::input_offsetalator d_offsets;
 
   __device__ void write_char(char_utf8 chr, char*& d_buffer, size_type& bytes)
   {
@@ -89,7 +90,7 @@ struct escape_strings_fn {
   __device__ void operator()(size_type idx)
   {
     if (d_column.is_null(idx)) {
-      if (!d_chars) d_offsets[idx] = 0;
+      if (!d_chars) { d_sizes[idx] = 0; }
       return;
     }
 
@@ -115,7 +116,7 @@ struct escape_strings_fn {
     }
     if (quote_row) write_char(quote, d_buffer, bytes);
 
-    if (!d_chars) d_offsets[idx] = bytes;
+    if (!d_chars) { d_sizes[idx] = bytes; }
   }
 };
 
@@ -182,7 +183,7 @@ 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 [offsets_column, chars] =
-      cudf::strings::detail::make_strings_children(fn, column_v.size(), stream_, mr_);
+      cudf::strings::detail::experimental::make_strings_children(fn, column_v.size(), stream_, mr_);
 
     return make_strings_column(column_v.size(),
                                std::move(offsets_column),

cpp/src/io/json/write_json.cu

@@ -36,7 +36,7 @@
 #include <cudf/scalar/scalar.hpp>
 #include <cudf/strings/detail/combine.hpp>
 #include <cudf/strings/detail/converters.hpp>
-#include <cudf/strings/detail/strings_children.cuh>
+#include <cudf/strings/detail/strings_children_ex.cuh>
 #include <cudf/strings/strings_column_view.hpp>
 #include <cudf/structs/structs_column_view.hpp>
 #include <cudf/table/table.hpp>
@@ -78,8 +78,9 @@ namespace {
 struct escape_strings_fn {
   column_device_view const d_column;
   bool const append_colon{false};
-  size_type* d_offsets{};
+  size_type* d_sizes{};
   char* d_chars{};
+  cudf::detail::input_offsetalator d_offsets;
 
   __device__ void write_char(char_utf8 chr, char*& d_buffer, size_type& bytes)
   {
@@ -123,7 +124,7 @@ struct escape_strings_fn {
   __device__ void operator()(size_type idx)
   {
     if (d_column.is_null(idx)) {
-      if (!d_chars) d_offsets[idx] = 0;
+      if (!d_chars) { d_sizes[idx] = 0; }
       return;
     }
 
@@ -163,15 +164,15 @@ struct escape_strings_fn {
     constexpr char_utf8 const colon = ':';  // append colon
     if (append_colon) write_char(colon, d_buffer, bytes);
 
-    if (!d_chars) d_offsets[idx] = bytes;
+    if (!d_chars) { d_sizes[idx] = bytes; }
   }
 
   std::unique_ptr<column> get_escaped_strings(column_view const& column_v,
                                               rmm::cuda_stream_view stream,
                                               rmm::device_async_resource_ref mr)
   {
-    auto [offsets_column, chars] =
-      cudf::strings::detail::make_strings_children(*this, column_v.size(), stream, mr);
+    auto [offsets_column, chars] = cudf::strings::detail::experimental::make_strings_children(
+      *this, column_v.size(), stream, mr);
 
     return make_strings_column(column_v.size(),
                                std::move(offsets_column),