Refactor std::array usage in row group index writing in ORC

CHANGELOG.md

@@ -115,6 +115,7 @@
 - PR #6835 Move template param to member var to improve compile of hash/groupby.cu
 - PR #6837 Avoid gather when copying strings view from start of strings column
 - PR #6859 Move align_ptr_for_type() from cuda.cuh to alignment.hpp
+- PR #6807 Refactor `std::array` usage in row group index writing in ORC
 
 ## Bug Fixes
 

cpp/src/io/orc/writer_impl.cu

@@ -39,6 +39,13 @@ namespace orc {
 using namespace cudf::io::orc;
 using namespace cudf::io;
 
+struct row_group_index_info {
+ int32_t pos = -1; // Position
+ int32_t blk_pos = -1; // Block Position
+ int32_t comp_pos = -1; // Compressed Position
+ int32_t comp_size = -1; // Compressed size
+};
+
 namespace {
 /**
  * @brief Helper for pinned host memory
@@ -858,36 +865,37 @@ void writer::impl::write_index_stream(int32_t stripe_id,
  std::vector<Stream> &streams,
  ProtobufWriter *pbw)
 {
- // 0: position, 1: block position, 2: compressed position, 3: compressed size
- std::array<int32_t, 4> present;
- std::array<int32_t, 4> data;
- std::array<int32_t, 4> data2;
+ row_group_index_info present;
+ row_group_index_info data;
+ row_group_index_info data2;
  auto kind = TypeKind::STRUCT;
 
  auto find_record = [=, &strm_desc](gpu::EncChunk const &chunk, gpu::StreamIndexType type) {
- std::array<int32_t, 4> record{-1, -1, -1, -1};
+ row_group_index_info record;
  if (chunk.strm_id[type] > 0) {
- record[0] = 0;
+ record.pos = 0;
  if (compression_kind_ != NONE) {
  const auto *ss =
  &strm_desc[stripe_id * num_data_streams + chunk.strm_id[type] - (num_columns + 1)];
- record[1] = ss->first_block;
- record[2] = 0;
- record[3] = ss->stream_size;
+ record.blk_pos  = ss->first_block;
+ record.comp_pos  = 0;
+ record.comp_size = ss->stream_size;
  }
  }
  return record;
  };
  auto scan_record = [=, &comp_out](gpu::EncChunk const &chunk,
  gpu::StreamIndexType type,
- std::array<int32_t, 4> &record) {
- if (record[0] >= 0) {
- record[0] += chunk.strm_len[type];
- while ((record[1] >= 0) && (static_cast<size_t>(record[0]) >= compression_blocksize_) &&
- (record[2] + 3 + comp_out[record[1]].bytes_written < static_cast<size_t>(record[3]))) {
- record[0] -= compression_blocksize_;
- record[2] += 3 + comp_out[record[1]].bytes_written;
- record[1] += 1;
+ row_group_index_info &record) {
+ if (record.pos >= 0) {
+ record.pos += chunk.strm_len[type];
+ while ((record.pos >= 0) && (record.blk_pos >= 0) &&
+ (static_cast<size_t>(record.pos) >= compression_blocksize_) &&
+ (record.comp_pos + 3 + comp_out[record.blk_pos].bytes_written <
+ static_cast<size_t>(record.comp_size))) {
+ record.pos -= compression_blocksize_;
+ record.comp_pos += 3 + comp_out[record.blk_pos].bytes_written;
+ record.blk_pos += 1;
  }
  }
  };
@@ -910,7 +918,8 @@ void writer::impl::write_index_stream(int32_t stripe_id,
 
  // Add row index entries
  for (size_t g = group; g < group + groups_in_stripe; g++) {
- pbw->put_row_index_entry(present[2], present[0], data[2], data[0], data2[2], data2[0], kind);
+ pbw->put_row_index_entry(
+ present.comp_pos, present.pos, data.comp_pos, data.pos, data2.comp_pos, data2.pos, kind);
 
  if (stream_id != 0) {
  const auto &ck = chunks[g * num_columns + stream_id - 1];