Add optimized 2x string column renumbering code (#1996)

Authors:
  - https://github.com/chirayuG-nvidia

Approvers:
  - Chuck Hastings (https://github.com/ChuckHastings)

URL: #1996

cpp/libcugraph_etl/CMakeLists.txt

@@ -1,5 +1,5 @@
 #=============================================================================
-# Copyright (c) 2021, NVIDIA CORPORATION.
+# Copyright (c) 2021-2022, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -119,6 +119,10 @@ target_compile_options(cugraph_etl
             PRIVATE "$<$<COMPILE_LANGUAGE:CXX>:${CUGRAPH_ETL_CXX_FLAGS}>"
 )
 
+target_compile_options(cugraph_etl PRIVATE $<$<COMPILE_LANGUAGE:CUDA>:
+                       --expt-relaxed-constexpr
+                       --expt-extended-lambda
+                       >)
 ################################################################################
 # - ETL include paths --------------------------------------------------------
 target_include_directories(cugraph_etl

cpp/libcugraph_etl/include/cugraph_etl/functions.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, NVIDIA CORPORATION.
+ * Copyright (c) 2021-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,8 @@
 #include <cudf/table/table.hpp>
 #include <cudf/types.hpp>
 
+#include <raft/handle.hpp>
+
 namespace cugraph {
 namespace etl {
 
@@ -47,7 +49,8 @@ namespace etl {
  */
 std::
   tuple<std::unique_ptr<cudf::column>, std::unique_ptr<cudf::column>, std::unique_ptr<cudf::table>>
-  renumber_cudf_tables(cudf::table_view const& src_table,
+  renumber_cudf_tables(raft::handle_t const& handle,
+                       cudf::table_view const& src_table,
                        cudf::table_view const& dst_table,
                        cudf::type_id dtype);