Change LIST column offsets from size_type to int32 in benchmarks and gtests

[davidwendt]

Description

Follow on work to #23607 includes changes to cpp/benchmarks and cpp/tests where cudf::size_type is used for LIST column offsets and replaced with int32_t instead.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.

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📥 Commits

Reviewing files that changed from the base of the PR and between 20fef07 and e0df26a.

📒 Files selected for processing (22)

• cpp/benchmarks/lists/copying/scatter_lists.cu
• cpp/tests/copying/concatenate_tests.cpp
• cpp/tests/copying/get_value_tests.cpp
• cpp/tests/copying/scatter_list_tests.cpp
• cpp/tests/groupby/collect_list_tests.cpp
• cpp/tests/hashing/murmurhash3_x86_32_test.cpp
• cpp/tests/io/cudftable_test.cpp
• cpp/tests/io/json/json_test.cpp
• cpp/tests/io/parquet_chunked_reader_test.cu
• cpp/tests/io/parquet_chunked_writer_test.cpp
• cpp/tests/io/parquet_reader_dict_test.cpp
• cpp/tests/io/parquet_reader_test.cpp
• cpp/tests/io/parquet_v2_test.cpp
• cpp/tests/lists/contains_tests.cpp
• cpp/tests/reductions/list_rank_test.cpp
• cpp/tests/reshape/byte_cast_tests.cpp
• cpp/tests/rolling/collect_ops_test.cpp
• cpp/tests/sort/top_k_tests.cpp
• cpp/tests/structs/structs_column_tests.cpp
• cpp/tests/transform/row_bit_count_test.cu
• cpp/tests/utilities/column_utilities.cu
• cpp/tests/utilities_tests/lists_column_wrapper_tests.cpp

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📝 Walkthrough

Summary by CodeRabbit

• Tests

  • Updated list-column test fixtures and utilities to use explicit 32-bit offset values.
  • Preserved existing test scenarios, expected results, and overflow assertions across copying, grouping, hashing, I/O, lists, reductions, sorting, structs, and transforms.
  • Improved consistency between test offsets and list-column storage behavior.

• Chores

  • Refreshed copyright years and attribution notices where applicable.

Walkthrough

The change standardizes list-column offset construction and access on explicit INT32 and int32_t types across benchmark code, utility code, and tests. Copyright notices and one empty-column type construction are also updated.

Changes

List offset alignment

Layer / File(s)	Summary
Offset access and benchmark construction cpp/benchmarks/lists/copying/scatter_lists.cu, cpp/tests/utilities/column_utilities.cu	Benchmark offsets and utility iterators now use explicit INT32 and int32_t types.
List construction and copying tests cpp/tests/copying/*, cpp/tests/groupby/collect_list_tests.cpp, cpp/tests/hashing/*, cpp/tests/structs/*, cpp/tests/utilities_tests/*	List, nested-list, and struct-list fixtures now construct offsets with int32_t.
Serialization and table IO fixtures cpp/tests/io/*	JSON, Parquet, and cudf-table fixtures now use int32_t list and map offsets.
Algorithm and transformation fixtures cpp/tests/lists/*, cpp/tests/reductions/*, cpp/tests/reshape/*, cpp/tests/rolling/*, cpp/tests/sort/*, cpp/tests/transform/*	Expected and constructed list offsets now use int32_t. Copyright notices are updated in affected files.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to e0df2

This change updates LIST offset types in benchmarks and tests without introducing an actionable merge-blocking risk; it is merge-ready after normal checks and review.

Possibly related PRs

• NVIDIA/cudf#23706: Refactors helper APIs for list-offset handling.
• NVIDIA/cudf#23688: Updates list-column test construction and offset handling.

Suggested reviewers: pointkernel, bdice

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 6.52% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: replacing LIST column offsets from cudf::size_type with int32 in benchmarks and tests.
Description check	✅ Passed	The description directly explains the offset type changes, affected directories, and relationship to PR #23607.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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• Create PR with unit tests

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