refractor(parquet): simplify FileReaderWrapper and PageFilteredRowGroupReader with unified TargetRowGroup structure

[zhf999]

Purpose

Linked issue: N/A
Pevious PR #330, please review #330 first.

Refactor FileReaderWrapper and PageFilteredRowGroupReader to improve readability, reduce code duplication, and simplify the calling interface:

1. Unify redundant member variables into TargetRowGroup struct — Replace scattered target_row_group_indices_, row_group_row_ranges_, page_filtered_indices_ with a single std::vector<TargetRowGroup> that carries row group index, page-filter flag, and row ranges together.
   The TargetRowGroup stuct is define as follows:

struct TargetRowGroup {
    int32_t row_group_index;
    bool is_page_filtered;
    // page-filtered row ranges, only valid if is_page_filtered is true.
    RowRanges row_ranges;
};

3. Simplify SetReadRanges calling chain — Introduce FileReaderWrapper::ApplyReadRanges() that directly mutates target_row_groups_ in-place, eliminating the round-trip through FilterRowGroupsByReadRanges → rebuild → PrepareForReadingLazy. Remove read_row_groups_ and read_column_indices_ from ParquetFileBatchReader.

4. Split long methods into focused helpers — Break PrepareForReading() (~120 lines), Next() (~100 lines), and SeekToRow() into smaller single-responsibility methods:

   • AdvanceToNextRowGroup(), NextPageFiltered(), NextFullyMatched()
   • BuildPageFilteredSchema(), CollectPreBufferRanges(), DispatchPreBuffer()

5. Refactor PageFilteredRowGroupReader — Extract GetPageRowRange() (eliminating 3x duplicated page row-range calculation), WaitForPreBuffer(), ExecuteSkipReadPattern(). Use TargetRowGroup in ReadFilteredRowGroup and ComputePageRanges signatures to reduce parameter count.

Tests

• All existing unit tests in paimon-parquet-format-test pass without modification to test logic (only call-site syntax adapted).
• Key test suites: FileReaderWrapperTest, PageFilteredRowGroupReaderTest, ParquetFileBatchReaderTest.

API and Format

• FileReaderWrapper::PrepareForReading / PrepareForReadingLazy now accept std::vector<TargetRowGroup> instead of std::set<int32_t>.
• FileReaderWrapper::FilterRowGroupsByReadRanges removed, replaced by ApplyReadRanges.
• PageFilteredRowGroupReader::ReadFilteredRowGroup / ComputePageRanges now accept const TargetRowGroup& instead of separate row_group_index + row_ranges.
• No storage format or protocol changes.

Documentation

No new features introduced. Internal refactoring only.

Generative AI tooling

Generated-by: Aone Copilot (Claude 4.7 Opus)

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Refactors Parquet reading to unify row-group targeting (including page-level filtered ranges), centralize Parquet/Arrow exception handling, and tighten predicate filtering behavior.

Changes:

• Introduces TargetRowGroup and propagates it through readers/tests to carry row-group index + page-filter row ranges.
• Moves PAIMON_PARQUET_CATCH_AND_RETURN_STATUS into a shared header and updates callers.
• Adds conservative fallback in ColumnIndexFilter when comparison predicates have empty literals, with new tests.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/paimon/format/parquet/row_ranges.h	Adds RowRanges move-ctor and introduces TargetRowGroup for carrying per-RG filtering info
src/paimon/format/parquet/parquet_format_defs.h	Adds shared macro to convert exceptions to Status
src/paimon/format/parquet/parquet_file_batch_reader.h	Switches read-range application to ApplyReadRanges
src/paimon/format/parquet/parquet_file_batch_reader.cpp	Refactors schema setup and read-range application around TargetRowGroup
src/paimon/format/parquet/page_filtered_row_group_reader.h	Updates APIs to accept TargetRowGroup and factors helpers into private methods
src/paimon/format/parquet/page_filtered_row_group_reader.cpp	Implements new helpers and updates page-filtered read logic to use TargetRowGroup
src/paimon/format/parquet/file_reader_wrapper.h	Replaces row-group index sets with TargetRowGroup list and adds ApplyReadRanges API
src/paimon/format/parquet/file_reader_wrapper.cpp	Refactors reading loop into page-filtered vs fully-matched paths, adds prebuffer range collection, implements ApplyReadRanges
src/paimon/format/parquet/page_filtered_row_group_reader_test.cpp	Updates tests to pass TargetRowGroup
src/paimon/format/parquet/file_reader_wrapper_test.cpp	Updates tests for new PrepareForReading* signatures and new ApplyReadRanges behavior
src/paimon/format/parquet/column_index_filter.cpp	Adds conservative fallback when literals are empty for non-null-check predicates
src/paimon/format/parquet/column_index_filter_test.cpp	Adds tests covering empty-literals behavior for comparison and IN predicates

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