feat(parquet): AuditReader::open_bytes for the RFC 0019 Store read path

[jensholdgaard]

What

RFC 0019 slice-2a prerequisite: AuditReader::open_bytes(Bytes) — so the querier's audit scan can read audit Parquet through the Store seam (Store::get_blocking → bytes → here) on local or S3, rather than std::fs.

How

• Mirrors the existing Reader::open_bytes: builds the ParquetRecordBatchReader from in-memory bytes::Bytes with the same §3.7 baseline-REQUIRED-column check, skipping row-vs-path validation (like open_file). No filesystem access → no Io error.
• Factors the builder + schema-check into a private from_chunk_reader<R: ChunkReader> helper shared by open_file (a File) and open_bytes (Bytes) — no duplication.

Tests

• audit_reader_open_bytes_round_trips: write events via AuditWriter, read the object's bytes, parse through open_bytes, assert full AuditEvent equality with what was written (parity with the on-disk path).
• cargo clippy -p ourios-parquet --all-targets --all-features -- -D warnings clean; cargo fmt --all --check green.

Context

Bounded, additive prerequisite for slice 2a (the querier Store migration). The §3.7 audit-isolation decision for that migration is settled (maintainer): rely on the #290 segment-wise prefix-scoped Store::list for tenant isolation, dropping the local-only symlink-canonicalize backstop (object storage — the production source of truth — has no symlinks; the residual local risk implies bucket write access). No §5 scenario flips green here; RFC 0019 stays red.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features
  • Added support for loading audit data directly from in-memory bytes, in addition to reading from disk.
  • Audit reads now use a shared code path so behavior stays consistent across input sources.
• Tests
  • Added coverage to confirm audit data round-trips correctly when read from in-memory bytes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 50ecf09b-1191-4e5e-b308-d9143a0dd285

📥 Commits

Reviewing files that changed from the base of the PR and between e71ed61 and cc69d63.

📒 Files selected for processing (2)

• crates/ourios-parquet/src/audit_reader.rs
• crates/ourios-parquet/tests/audit_round_trip.rs

🚧 Files skipped from review as they are similar to previous changes (2)

• crates/ourios-parquet/tests/audit_round_trip.rs
• crates/ourios-parquet/src/audit_reader.rs

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📝 Walkthrough

Walkthrough

AuditReader now accepts in-memory audit parquet bytes through a new open_bytes entry point. The shared chunk-reader constructor now accepts an explicit file path, and a new test reads written audit data back from bytes and compares it to the original events.

Changes

Audit bytes-backed reader

Layer / File(s)	Summary
Bytes-backed reader setup crates/ourios-parquet/src/audit_reader.rs	AuditReader::open_bytes forwards bytes::Bytes through the shared chunk-reader path, and the shared constructor now takes an explicit file path while storing that value on the reader.
Round-trip test crates/ourios-parquet/tests/audit_round_trip.rs	A test writes audit events, reads the produced parquet file as bytes, parses it with AuditReader::open_bytes, and compares the decoded events to the originals.

Sequence Diagram(s)

sequenceDiagram
  participant Test
  participant AuditWriter
  participant FileSystem
  participant AuditReader
  participant from_chunk_reader

  Test->>AuditWriter: write three_variants("acme")
  AuditWriter->>FileSystem: write audit parquet file
  Test->>FileSystem: read raw bytes
  Test->>AuditReader: open_bytes(bytes)
  AuditReader->>from_chunk_reader: open_bytes(bytes, "<object-store>")
  from_chunk_reader-->>AuditReader: parsed AuditReader
  AuditReader-->>Test: decoded events

Loading

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

I hopped through bytes with twitchy nose,
and traced the audit where parquet flows.
A memory burrow, neat and bright,
returned the events in one soft bite.
🐰✨ Hop-happy audit trail!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly names the new open_bytes API and the RFC 0019 store read path.
Description check	✅ Passed	It covers the change, rationale, tests, and RFC context, but it doesn't follow the template's exact Summary/Related/Checklist structure.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
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.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch rfc0019-audit-reader-open-bytes

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[Copilot]

Pull request overview

Adds an in-memory audit Parquet read entry point to support the RFC 0019 querier migration onto the Store seam (reading via Store::get_blocking → bytes) instead of directly from std::fs.

Changes:

• Introduces AuditReader::open_bytes(Bytes) for reading audit Parquet from in-memory bytes.
• Refactors shared Parquet-builder + required-column schema validation into from_chunk_reader<R: ChunkReader>, used by both open_file and open_bytes.
• Adds a round-trip test asserting open_bytes produces identical AuditEvents to what AuditWriter wrote.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
crates/ourios-parquet/src/audit_reader.rs	Adds open_bytes and factors common ChunkReader-based reader construction with required-column checks.
crates/ourios-parquet/tests/audit_round_trip.rs	Adds a round-trip test covering the new in-memory open_bytes audit read path.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/ourios-parquet/tests/audit_round_trip.rs`:
- Around line 194-217: The round-trip coverage for AuditReader::open_bytes is
currently only an integration-style example in audit_round_trip.rs, but it needs
to live next to the AuditReader implementation and be expressed as a property
test. Move the test into src/audit_reader.rs alongside
AuditReader::open_bytes/open_file, and rewrite it using proptest so it checks
the reconstruction invariant across generated event sequences rather than a
single fixed fixture. Keep the assertion that bytes read from the written audit
object round-trip through AuditReader::open_bytes and match the original events.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: e8351657-c165-4cd7-aca3-99a3baf5a734

📥 Commits

Reviewing files that changed from the base of the PR and between dcf8917 and e71ed61.

📒 Files selected for processing (2)

• crates/ourios-parquet/src/audit_reader.rs
• crates/ourios-parquet/tests/audit_round_trip.rs

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.