Merge complementary cached article sections

[mjc]

Summary

• preserve retained HEAD data across successful status updates
• merge compatible HEAD and BODY sections into a complete ARTICLE payload
• require matching message identity and article number before combining sections

Branch-added tests

• A successful status update test verifies a retained HEAD section survives the metadata refresh.
• A complementary-section test verifies matching HEAD and BODY data becomes an ARTICLE while incompatible identity or number data does not merge.
• Existing article cache hit, ingest, and response-shape coverage remains green.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Repository UI (base), Organization UI (inherited)

Review profile: ASSERTIVE

Plan: Advanced

Run ID: 4a23fb7f-35fe-4baf-a019-ee342f6d97d7

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[Copilot]

🟡 Changes recommended

Tier-aware TTL handling during merges/status refreshes and missing negative-case tests leave correctness/operational behavior mismatched with the PR’s stated intent.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR extends the hybrid article cache to retain cached HEAD payloads across successful status-only refreshes, and to merge complementary cached HEAD/BODY sections into a complete ARTICLE entry when compatible.

Changes:

• Adds HEAD+BODY → ARTICLE merge support during upsert_ingest_for_slot when an existing entry and a new entry contain complementary sections.
• Adjusts status-only refresh logic so it no longer overwrites retained HEAD payloads.
• Adds unit tests for retained HEAD survival across status updates and for the happy-path complementary merge.

File summaries

File	Description
src/cache/hybrid.rs	Attempts an in-place merge of an existing cached section with a newly ingested complementary section before falling back to size/semantic overwrite rules.
src/cache/hybrid_codec.rs	Implements section-merge logic on DiskCachedArticle, narrows when status-only refresh overwrites payload, and adds merge/status-refresh tests.

Review details

Suppressed comments (1)

src/cache/hybrid_codec.rs:692

• record_backend_has_status no longer updates tier unless the payload is Missing/AvailabilityOnly. With the new goal of preserving HEAD across status updates, this means a successful status refresh from a higher-tier backend won't extend the entry's tier-aware TTL, potentially increasing repeat queries against that backend.

        if matches!(
            self.payload,
            CachedPayload::Missing | CachedPayload::AvailabilityOnly
        ) {
            self.status_code = status_code;
            self.payload = CachedPayload::AvailabilityOnly;
            self.tier = tier;
        }

• Files reviewed: 2/2 changed files
• Comments generated: 2
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.