Add row bitmask as a detail::hash_join member

cpp/include/cudf/detail/join.hpp

@@ -22,6 +22,7 @@
 #include <cudf/types.hpp>
 
 #include <rmm/cuda_stream_view.hpp>
+#include <rmm/device_buffer.hpp>
 #include <rmm/device_uvector.hpp>
 #include <rmm/mr/device/polymorphic_allocator.hpp>
 
@@ -68,9 +69,10 @@ struct hash_join {
   hash_join& operator=(hash_join&&) = delete;
 
  private:
-  bool const _is_empty;                    ///< true if `_hash_table` is empty
-  cudf::null_equality const _nulls_equal;  ///< whether to consider nulls as equal
-  cudf::table_view _build;                 ///< input table to build the hash map
+  bool const _is_empty;                         ///< true if `_hash_table` is empty
+  rmm::device_buffer const _composite_bitmask;  ///< Bitmask to denote whether a row is valid
+  cudf::null_equality const _nulls_equal;       ///< whether to consider nulls as equal
+  cudf::table_view _build;                      ///< input table to build the hash map
   cudf::structs::detail::flattened_table
     _flattened_build_table;  ///< flattened data structures for `_build`
   map_type _hash_table;      ///< hash table built on `_build`

cpp/src/join/hash_join.cu

@@ -283,6 +283,7 @@ hash_join<Hasher>::hash_join(cudf::table_view const& build,
                              cudf::null_equality compare_nulls,
                              rmm::cuda_stream_view stream)
   : _is_empty{build.num_rows() == 0},
+    _composite_bitmask{cudf::detail::bitmask_and(build, stream).first},
     _nulls_equal{compare_nulls},
     _hash_table{compute_hash_table_size(build.num_rows()),
                 std::numeric_limits<hash_value_type>::max(),
@@ -302,7 +303,11 @@ hash_join<Hasher>::hash_join(cudf::table_view const& build,
 
   if (_is_empty) { return; }
 
-  cudf::detail::build_join_hash_table(_build, _hash_table, _nulls_equal, stream);
+  cudf::detail::build_join_hash_table(_build,
+                                      _hash_table,
+                                      _nulls_equal,
+                                      static_cast<bitmask_type const*>(_composite_bitmask.data()),
+                                      stream);
 }
 
 template <typename Hasher>

cpp/src/join/join_common_utils.cuh

@@ -143,13 +143,15 @@ get_trivial_left_join_indices(
  * @param build Table of columns used to build join hash.
  * @param hash_table Build hash table.
  * @param nulls_equal Flag to denote nulls are equal or not.
+ * @param bitmask Bitmask to denote whether a row is valid.
  * @param stream CUDA stream used for device memory operations and kernel launches.
  *
  */
 template <typename MultimapType>
 void build_join_hash_table(cudf::table_view const& build,
                            MultimapType& hash_table,
                            null_equality const nulls_equal,
+                           [[maybe_unused]] bitmask_type const* bitmask,
                            rmm::cuda_stream_view stream)
 {
   auto build_table_ptr = cudf::table_device_view::create(build, stream);
@@ -168,8 +170,7 @@ void build_join_hash_table(cudf::table_view const& build,
     hash_table.insert(iter, iter + build_table_num_rows, stream.value());
   } else {
     thrust::counting_iterator<size_type> stencil(0);
-    auto const row_bitmask = cudf::detail::bitmask_and(build, stream).first;
-    row_is_valid pred{static_cast<bitmask_type const*>(row_bitmask.data())};
+    row_is_valid pred{bitmask};
 
     // insert valid rows
     hash_table.insert_if(iter, iter + build_table_num_rows, stencil, pred, stream.value());

cpp/src/join/mixed_join.cu

@@ -135,7 +135,9 @@ mixed_join(
   // TODO: To add support for nested columns we will need to flatten in many
   // places. However, this probably isn't worth adding any time soon since we
   // won't be able to support AST conditions for those types anyway.
-  build_join_hash_table(build, hash_table, compare_nulls, stream);
+  auto const row_bitmask = cudf::detail::bitmask_and(build, stream).first;
+  build_join_hash_table(
+    build, hash_table, compare_nulls, static_cast<bitmask_type const*>(row_bitmask.data()), stream);
   auto hash_table_view = hash_table.get_device_view();
 
   auto left_conditional_view  = table_device_view::create(left_conditional, stream);
@@ -381,7 +383,9 @@ compute_mixed_join_output_size(table_view const& left_equality,
   // TODO: To add support for nested columns we will need to flatten in many
   // places. However, this probably isn't worth adding any time soon since we
   // won't be able to support AST conditions for those types anyway.
-  build_join_hash_table(build, hash_table, compare_nulls, stream);
+  auto const row_bitmask = cudf::detail::bitmask_and(build, stream).first;
+  build_join_hash_table(
+    build, hash_table, compare_nulls, static_cast<bitmask_type const*>(row_bitmask.data()), stream);
   auto hash_table_view = hash_table.get_device_view();
 
   auto left_conditional_view  = table_device_view::create(left_conditional, stream);