Remove the libcudf cudf::offset_type type (#13788)

Replace all occurrences  of `cudf::offset_type` with `cudf::size_type`
This helps clear up code where sizes are computed and then converted to offsets in-place.

Also, reference #13733

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

Approvers:
  - https://github.com/brandon-b-miller
  - Nghia Truong (https://github.com/ttnghia)
  - Bradley Dice (https://github.com/bdice)
  - MithunR (https://github.com/mythrocks)

URL: #13788

cpp/benchmarks/copying/contiguous_split.cu

@@ -151,7 +151,7 @@ void BM_contiguous_split_strings(benchmark::State& state, ContiguousSplitImpl& i
   }
 
   int64_t const total_bytes =
-    total_desired_bytes + ((num_rows + 1) * sizeof(cudf::offset_type)) +
+    total_desired_bytes + ((num_rows + 1) * sizeof(cudf::size_type)) +
     (include_validity ? (max(int64_t{1}, (num_rows / 32)) * sizeof(cudf::bitmask_type) * num_cols)
                       : 0);
 

cpp/benchmarks/lists/copying/scatter_lists.cu

@@ -62,26 +62,26 @@ void BM_lists_scatter(::benchmark::State& state)
                    target_base_col->mutable_view().end<TypeParam>());
 
   auto source_offsets =
-    make_fixed_width_column(cudf::data_type{cudf::type_to_id<cudf::offset_type>()},
+    make_fixed_width_column(cudf::data_type{cudf::type_to_id<cudf::size_type>()},
                             num_rows + 1,
                             cudf::mask_state::UNALLOCATED,
                             stream,
                             mr);
   auto target_offsets =
-    make_fixed_width_column(cudf::data_type{cudf::type_to_id<cudf::offset_type>()},
+    make_fixed_width_column(cudf::data_type{cudf::type_to_id<cudf::size_type>()},
                             num_rows + 1,
                             cudf::mask_state::UNALLOCATED,
                             stream,
                             mr);
 
   thrust::sequence(rmm::exec_policy(stream),
-                   source_offsets->mutable_view().begin<cudf::offset_type>(),
-                   source_offsets->mutable_view().end<cudf::offset_type>(),
+                   source_offsets->mutable_view().begin<cudf::size_type>(),
+                   source_offsets->mutable_view().end<cudf::size_type>(),
                    0,
                    num_elements_per_row);
   thrust::sequence(rmm::exec_policy(stream),
-                   target_offsets->mutable_view().begin<cudf::offset_type>(),
-                   target_offsets->mutable_view().end<cudf::offset_type>(),
+                   target_offsets->mutable_view().begin<cudf::size_type>(),
+                   target_offsets->mutable_view().end<cudf::size_type>(),
                    0,
                    num_elements_per_row);
 

cpp/examples/strings/custom_prealloc.cu

@@ -41,7 +41,7 @@ __global__ void redact_kernel(cudf::column_device_view const d_names,
                               cudf::column_device_view const d_visibilities,
                               cudf::string_view redaction,
                               char* working_memory,
-                              cudf::offset_type const* d_offsets,
+                              cudf::size_type const* d_offsets,
                               cudf::string_view* d_output)
 {
   // The row index is resolved from the CUDA thread/block objects

cpp/include/cudf/detail/sizes_to_offsets_iterator.cuh

@@ -303,9 +303,9 @@ std::pair<std::unique_ptr<column>, size_type> make_offsets_child_column(
 {
   auto count          = static_cast<size_type>(std::distance(begin, end));
   auto offsets_column = make_numeric_column(
-    data_type{type_to_id<offset_type>()}, count + 1, mask_state::UNALLOCATED, stream, mr);
+    data_type{type_to_id<size_type>()}, count + 1, mask_state::UNALLOCATED, stream, mr);
   auto offsets_view = offsets_column->mutable_view();
-  auto d_offsets    = offsets_view.template data<offset_type>();
+  auto d_offsets    = offsets_view.template data<size_type>();
 
   // The number of offsets is count+1 so to build the offsets from the sizes
   // using exclusive-scan technically requires count+1 input values even though

cpp/include/cudf/lists/detail/scatter.cuh

@@ -240,11 +240,11 @@ std::unique_ptr<column> scatter(scalar const& slr,
   rmm::device_buffer null_mask =
     slr_valid ? cudf::detail::create_null_mask(1, mask_state::UNALLOCATED, stream, mr)
               : cudf::detail::create_null_mask(1, mask_state::ALL_NULL, stream, mr);
-  auto offset_column = make_numeric_column(
-    data_type{type_to_id<offset_type>()}, 2, mask_state::UNALLOCATED, stream, mr);
+  auto offset_column =
+    make_numeric_column(data_type{type_to_id<size_type>()}, 2, mask_state::UNALLOCATED, stream, mr);
   thrust::sequence(rmm::exec_policy_nosync(stream),
-                   offset_column->mutable_view().begin<offset_type>(),
-                   offset_column->mutable_view().end<offset_type>(),
+                   offset_column->mutable_view().begin<size_type>(),
+                   offset_column->mutable_view().end<size_type>(),
                    0,
                    lv->view().size());
   auto wrapped = column_view(data_type{type_id::LIST},

cpp/include/cudf/lists/lists_column_view.hpp

@@ -71,9 +71,7 @@ class lists_column_view : private column_view {
   using column_view::null_mask;
   using column_view::offset;
   using column_view::size;
-  static_assert(std::is_same_v<offset_type, size_type>,
-                "offset_type is expected to be the same as size_type.");
-  using offset_iterator = offset_type const*;  ///< Iterator type for offsets
+  using offset_iterator = size_type const*;  ///< Iterator type for offsets
 
   /**
    * @brief Returns the parent column.
@@ -119,7 +117,7 @@ class lists_column_view : private column_view {
    */
   [[nodiscard]] offset_iterator offsets_begin() const noexcept
   {
-    return offsets().begin<offset_type>() + offset();
+    return offsets().begin<size_type>() + offset();
   }
 
   /**

cpp/include/cudf/strings/strings_column_view.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2022, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -67,8 +67,8 @@ class strings_column_view : private column_view {
   using column_view::offset;
   using column_view::size;
 
-  using offset_iterator = offset_type const*;  ///< offsets iterator type
-  using chars_iterator  = char const*;         ///< character iterator type
+  using offset_iterator = size_type const*;  ///< offsets iterator type
+  using chars_iterator  = char const*;       ///< character iterator type
 
   /**
    * @brief Returns the parent column.

cpp/include/cudf/tdigest/tdigest_column_view.hpp

@@ -67,9 +67,7 @@ class tdigest_column_view : private column_view {
   tdigest_column_view& operator=(tdigest_column_view&&) = default;
 
   using column_view::size;
-  static_assert(std::is_same_v<offset_type, size_type>,
-                "offset_type is expected to be the same as size_type.");
-  using offset_iterator = offset_type const*;  ///< Iterator over offsets
+  using offset_iterator = size_type const*;  ///< Iterator over offsets
 
   // mean and weight column indices within tdigest inner struct columns
   static constexpr size_type mean_column_index{0};    ///< Mean column index

cpp/include/cudf/types.hpp

@@ -80,7 +80,6 @@ class mutable_table_view;
 using size_type         = int32_t;   ///< Row index type for columns and tables
 using bitmask_type      = uint32_t;  ///< Bitmask type stored as 32-bit unsigned integer
 using valid_type        = uint8_t;   ///< Valid type in host memory
-using offset_type       = int32_t;   ///< Offset type for column offsets
 using thread_index_type = int64_t;   ///< Thread index type in kernels
 
 /**

cpp/include/cudf_test/column_utilities.hpp

@@ -261,8 +261,8 @@ inline std::pair<thrust::host_vector<std::string>, std::vector<bitmask_type>> to
       cudf::device_span<char const>(scv.chars().data<char>(), scv.chars().size()),
       cudf::get_default_stream());
     auto const h_offsets = cudf::detail::make_std_vector_sync(
-      cudf::device_span<cudf::offset_type const>(
-        scv.offsets().data<cudf::offset_type>() + scv.offset(), scv.size() + 1),
+      cudf::device_span<cudf::size_type const>(scv.offsets().data<cudf::size_type>() + scv.offset(),
+                                               scv.size() + 1),
       cudf::get_default_stream());
 
     // build std::string vector from chars and offsets

cpp/include/cudf_test/column_wrapper.hpp

@@ -1507,7 +1507,7 @@ class lists_column_wrapper : public detail::column_wrapper {
    */
   static lists_column_wrapper<T> make_one_empty_row_column(bool valid = true)
   {
-    cudf::test::fixed_width_column_wrapper<cudf::offset_type> offsets{0, 0};
+    cudf::test::fixed_width_column_wrapper<cudf::size_type> offsets{0, 0};
     cudf::test::fixed_width_column_wrapper<int> values{};
     return lists_column_wrapper<T>(
       1,

cpp/src/copying/concatenate.cu

@@ -408,15 +408,15 @@ void traverse_children::operator()<cudf::string_view>(host_span<column_view cons
       return a + (scv.is_empty() ? 0
                   // if the column is unsliced, skip the offset retrieval.
                   : scv.offset() > 0
-                    ? cudf::detail::get_value<offset_type>(
+                    ? cudf::detail::get_value<size_type>(
                         scv.offsets(), scv.offset() + scv.size(), stream) -
-                        cudf::detail::get_value<offset_type>(scv.offsets(), scv.offset(), stream)
+                        cudf::detail::get_value<size_type>(scv.offsets(), scv.offset(), stream)
                   // if the offset() is 0, it can still be sliced to a shorter length. in this case
                   // we only need to read a single offset. otherwise just return the full length
                   // (chars_size())
                   : scv.size() + 1 == scv.offsets().size()
                     ? scv.chars_size()
-                    : cudf::detail::get_value<offset_type>(scv.offsets(), scv.size(), stream));
+                    : cudf::detail::get_value<size_type>(scv.offsets(), scv.size(), stream));
     });
   CUDF_EXPECTS(total_char_count <= static_cast<size_t>(std::numeric_limits<size_type>::max()),
                "Total number of concatenated chars exceeds the column size limit",

cpp/src/copying/contiguous_split.cu

@@ -939,7 +939,7 @@ struct batch_byte_size_function {
  * @brief Get the input buffer index given the output buffer index.
  */
 struct out_to_in_index_function {
-  offset_type const* const batch_offsets;
+  size_type const* const batch_offsets;
   int const num_bufs;
   __device__ int operator()(size_type i) const
   {
@@ -1312,7 +1312,7 @@ std::unique_ptr<packed_partition_buf_size_and_dst_buf_info> compute_splits(
  */
 struct chunk_iteration_state {
   chunk_iteration_state(rmm::device_uvector<dst_buf_info> _d_batched_dst_buf_info,
-                        rmm::device_uvector<offset_type> _d_batch_offsets,
+                        rmm::device_uvector<size_type> _d_batch_offsets,
                         std::vector<std::size_t>&& _h_num_buffs_per_iteration,
                         std::vector<std::size_t>&& _h_size_of_buffs_per_iteration,
                         std::size_t total_size)
@@ -1375,11 +1375,10 @@ struct chunk_iteration_state {
   bool has_more_copies() const { return current_iteration < num_iterations; }
 
   rmm::device_uvector<dst_buf_info> d_batched_dst_buf_info;  ///< dst_buf_info per 1MB batch
-  rmm::device_uvector<offset_type> const
-    d_batch_offsets;             ///< Offset within a batch per dst_buf_info
-  std::size_t const total_size;  ///< The aggregate size of all iterations
-  int const num_iterations;      ///< The total number of iterations
-  int current_iteration;         ///< Marks the current iteration being worked on
+  rmm::device_uvector<size_type> const d_batch_offsets;  ///< Offset within a batch per dst_buf_info
+  std::size_t const total_size;                          ///< The aggregate size of all iterations
+  int const num_iterations;                              ///< The total number of iterations
+  int current_iteration;  ///< Marks the current iteration being worked on
 
  private:
   std::size_t starting_batch;  ///< Starting batch index for the current iteration
@@ -1398,7 +1397,7 @@ std::unique_ptr<chunk_iteration_state> chunk_iteration_state::create(
   rmm::cuda_stream_view stream,
   rmm::mr::device_memory_resource* temp_mr)
 {
-  rmm::device_uvector<offset_type> d_batch_offsets(num_bufs + 1, stream, temp_mr);
+  rmm::device_uvector<size_type> d_batch_offsets(num_bufs + 1, stream, temp_mr);
 
   auto const buf_count_iter = cudf::detail::make_counting_transform_iterator(
     0, [num_bufs, num_batches = num_batches_func{batches.begin()}] __device__(size_type i) {

cpp/src/groupby/groupby.cu

@@ -107,7 +107,7 @@ struct empty_column_constructor {
 
     if constexpr (k == aggregation::Kind::COLLECT_LIST || k == aggregation::Kind::COLLECT_SET) {
       return make_lists_column(
-        0, make_empty_column(type_to_id<offset_type>()), empty_like(values), 0, {});
+        0, make_empty_column(type_to_id<size_type>()), empty_like(values), 0, {});
     }
 
     if constexpr (k == aggregation::Kind::RANK) {

cpp/src/groupby/sort/group_collect.cu

@@ -96,12 +96,12 @@ std::unique_ptr<column> group_collect(column_view const& values,
   auto [child_column,
         offsets_column] = [null_handling, num_groups, &values, &group_offsets, stream, mr] {
     auto offsets_column = make_numeric_column(
-      data_type(type_to_id<offset_type>()), num_groups + 1, mask_state::UNALLOCATED, stream, mr);
+      data_type(type_to_id<size_type>()), num_groups + 1, mask_state::UNALLOCATED, stream, mr);
 
     thrust::copy(rmm::exec_policy(stream),
                  group_offsets.begin(),
                  group_offsets.end(),
-                 offsets_column->mutable_view().template begin<offset_type>());
+                 offsets_column->mutable_view().template begin<size_type>());
 
     // If column of grouped values contains null elements, and null_policy == EXCLUDE,
     // those elements must be filtered out, and offsets recomputed.

cpp/src/groupby/sort/group_merge_lists.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, NVIDIA CORPORATION.
+ * Copyright (c) 2021-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -38,7 +38,7 @@ std::unique_ptr<column> group_merge_lists(column_view const& values,
                "Input to `group_merge_lists` must be a non-nullable lists column.");
 
   auto offsets_column = make_numeric_column(
-    data_type(type_to_id<offset_type>()), num_groups + 1, mask_state::UNALLOCATED, stream, mr);
+    data_type(type_to_id<size_type>()), num_groups + 1, mask_state::UNALLOCATED, stream, mr);
 
   // Generate offsets of the output lists column by gathering from the provided group offsets and
   // the input list offsets.
@@ -54,7 +54,7 @@ std::unique_ptr<column> group_merge_lists(column_view const& values,
                  group_offsets.begin(),
                  group_offsets.end(),
                  lists_column_view(values).offsets_begin(),
-                 offsets_column->mutable_view().template begin<offset_type>());
+                 offsets_column->mutable_view().template begin<size_type>());
 
   // The child column of the output lists column is just copied from the input column.
   auto child_column =

cpp/src/io/csv/writer_impl.cu

@@ -75,10 +75,10 @@ namespace {
 struct escape_strings_fn {
   column_device_view const d_column;
   string_view const d_delimiter;  // check for column delimiter
-  offset_type* d_offsets{};
+  size_type* d_offsets{};
   char* d_chars{};
 
-  __device__ void write_char(char_utf8 chr, char*& d_buffer, offset_type& bytes)
+  __device__ void write_char(char_utf8 chr, char*& d_buffer, size_type& bytes)
   {
     if (d_buffer)
       d_buffer += cudf::strings::detail::from_char_utf8(chr, d_buffer);
@@ -105,8 +105,8 @@ struct escape_strings_fn {
         return chr == quote || chr == new_line || chr == d_delimiter[0];
       });
 
-    char* d_buffer    = d_chars ? d_chars + d_offsets[idx] : nullptr;
-    offset_type bytes = 0;
+    char* d_buffer  = d_chars ? d_chars + d_offsets[idx] : nullptr;
+    size_type bytes = 0;
 
     if (quote_row) write_char(quote, d_buffer, bytes);
     for (auto chr : d_str) {

cpp/src/io/json/json_column.cu

@@ -363,8 +363,8 @@ std::vector<std::string> copy_strings_to_host(device_span<SymbolT const> input,
       cudf::device_span<char const>(scv.chars().data<char>(), scv.chars().size()),
       cudf::get_default_stream());
     auto const h_offsets = cudf::detail::make_std_vector_sync(
-      cudf::device_span<cudf::offset_type const>(
-        scv.offsets().data<cudf::offset_type>() + scv.offset(), scv.size() + 1),
+      cudf::device_span<cudf::size_type const>(scv.offsets().data<cudf::size_type>() + scv.offset(),
+                                               scv.size() + 1),
       cudf::get_default_stream());
 
     // build std::string vector from chars and offsets

cpp/src/io/json/write_json.cu

@@ -75,10 +75,10 @@ namespace {
 struct escape_strings_fn {
   column_device_view const d_column;
   bool const append_colon{false};
-  offset_type* d_offsets{};
+  size_type* d_offsets{};
   char* d_chars{};
 
-  __device__ void write_char(char_utf8 chr, char*& d_buffer, offset_type& bytes)
+  __device__ void write_char(char_utf8 chr, char*& d_buffer, size_type& bytes)
   {
     if (d_buffer)
       d_buffer += cudf::strings::detail::from_char_utf8(chr, d_buffer);
@@ -91,7 +91,7 @@ struct escape_strings_fn {
     return nibble < 10 ? '0' + nibble : 'a' + nibble - 10;
   }
 
-  __device__ void write_utf8_codepoint(uint16_t codepoint, char*& d_buffer, offset_type& bytes)
+  __device__ void write_utf8_codepoint(uint16_t codepoint, char*& d_buffer, size_type& bytes)
   {
     if (d_buffer) {
       d_buffer[0] = '\\';
@@ -106,7 +106,7 @@ struct escape_strings_fn {
     }
   }
 
-  __device__ void write_utf16_codepoint(uint32_t codepoint, char*& d_buffer, offset_type& bytes)
+  __device__ void write_utf16_codepoint(uint32_t codepoint, char*& d_buffer, size_type& bytes)
   {
     constexpr uint16_t UTF16_HIGH_SURROGATE_BEGIN = 0xD800;
     constexpr uint16_t UTF16_LOW_SURROGATE_BEGIN  = 0xDC00;
@@ -130,8 +130,8 @@ struct escape_strings_fn {
     constexpr char_utf8 const quote = '\"';  // wrap quotes
     bool constexpr quote_row        = true;
 
-    char* d_buffer    = d_chars ? d_chars + d_offsets[idx] : nullptr;
-    offset_type bytes = 0;
+    char* d_buffer  = d_chars ? d_chars + d_offsets[idx] : nullptr;
+    size_type bytes = 0;
 
     if (quote_row) write_char(quote, d_buffer, bytes);
     for (auto utf8_char : d_str) {

cpp/src/io/parquet/reader_impl_preprocess.cu

@@ -1016,7 +1016,7 @@ struct row_size_functor {
 template <>
 __device__ size_t row_size_functor::operator()<list_view>(size_t num_rows, bool nullable)
 {
-  auto const offset_size = sizeof(offset_type);
+  auto const offset_size = sizeof(size_type);
   // NOTE: Adding the + 1 offset here isn't strictly correct.  There will only be 1 extra offset
   // for the entire column, whereas this is adding an extra offset per page.  So we will get a
   // small over-estimate of the real size of the order :  # of pages * 4 bytes. It seems better
@@ -1036,7 +1036,7 @@ __device__ size_t row_size_functor::operator()<string_view>(size_t num_rows, boo
 {
   // only returns the size of offsets and validity. the size of the actual string chars
   // is tracked separately.
-  auto const offset_size = sizeof(offset_type);
+  auto const offset_size = sizeof(size_type);
   // see note about offsets in the list_view template.
   return (offset_size * (num_rows + 1)) + validity_size(num_rows, nullable);
 }

cpp/src/io/statistics/statistics.cuh

@@ -132,7 +132,7 @@ __device__ T get_element(column_device_view const& col, uint32_t row)
 {
   using et              = typename T::element_type;
   size_type const index = row + col.offset();  // account for this view's _offset
-  auto const* d_offsets = col.child(lists_column_view::offsets_column_index).data<offset_type>();
+  auto const* d_offsets = col.child(lists_column_view::offsets_column_index).data<size_type>();
   auto const* d_data    = col.child(lists_column_view::child_column_index).data<et>();
   auto const offset     = d_offsets[index];
   return T(d_data + offset, d_offsets[index + 1] - offset);