Fix reranker implementation with new code

[ljt019]

Refactor Qwen3 reranker to use a minimal, working implementation for correct and faster relevance scoring.

Summary by CodeRabbit

• New Features
  • Introduced a new minimal implementation of the Qwen3 reranker model, supporting quantized model loading and inference.
• Improvements
  • Simplified relevance scoring by directly comparing logits for "yes" and "no" tokens, resulting in clearer and more efficient scoring.
• Bug Fixes
  • Removed unused helper methods to streamline the codebase.

[coderabbitai]

Caution

Review failed

The pull request is closed.

Walkthrough

This update introduces a minimal internal implementation for the Qwen3 reranker model, including model architecture, GGUF quantized weight loading, and a revised relevance scoring logic. The scoring now compares logits for "yes" and "no" tokens directly, simplifying the previous token aggregation approach. Several new structs and methods are added for model components.

Changes

File(s)	Change Summary
src/models/implementations/qwen3_reranker.rs	Added minimal Qwen3 reranker model implementation: GGUF loader, model components, and forward pass.
src/models/implementations/qwen3_reranker.rs	Refactored compute_relevance_score to use direct "yes"/"no" logit comparison; removed helper.
src/models/implementations/qwen3_reranker.rs	Added/modified exported structs and methods for model loading and inference.

Sequence Diagram(s)

sequenceDiagram
    participant User
    participant Qwen3RerankModel
    participant Tokenizer
    participant ModelWeights

    User->>Qwen3RerankModel: compute_relevance_score(query, doc)
    Qwen3RerankModel->>Tokenizer: encode(formatted_prompt, add_special_tokens=true)
    Tokenizer-->>Qwen3RerankModel: token_ids
    Qwen3RerankModel->>ModelWeights: forward(token_ids)
    ModelWeights-->>Qwen3RerankModel: logits
    Qwen3RerankModel->>Qwen3RerankModel: extract "yes" and "no" logits
    Qwen3RerankModel-->>User: relevance_score = logits["yes"] - logits["no"]

Loading

Possibly related PRs

• ljt019/transformers#63: Adds an example and pipeline integration using the Qwen3 reranker model, complementing the internal implementation introduced here.

Suggested labels

codex

Poem

In bytes and weights, a model awakes,
Qwen3 reranker, now fewer mistakes!
"Yes" and "no" in a logit dance,
Direct and simple, we give them a chance.
With GGUF loaded and tensors aligned,
A rabbit hops forward, leaving old code behind!
🐇✨

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 Clippy (1.86.0)

Updating crates.io index
Updating git repository `https://github.com/huggingface/candle.git`

error: failed to get candle-core as a dependency of package transformers v0.0.13 ()

Caused by:
failed to load source for dependency candle-core

Caused by:
Unable to update https://github.com/huggingface/candle.git#d0a3b33e

Caused by:
failed to create directory /usr/local/git/db/candle-5b4d092929d18d36

Caused by:
Permission denied (os error 13)

---

📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6e60d86 and a3980a0.

📒 Files selected for processing (1)

• src/models/implementations/qwen3_reranker.rs (3 hunks)

✨ Finishing Touches

• 📝 Generate Docstrings

---

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

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Explain this complex logic.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
  • @coderabbitai explain this code block.
  • @coderabbitai modularize this function.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbitai read src/utils.ts and explain its main purpose.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
  • @coderabbitai help me debug CodeRabbit configuration file.

Support

Need help? Create a ticket on our support page for assistance with any issues or questions.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai generate docstrings to generate docstrings for this PR.
• @coderabbitai generate sequence diagram to generate a sequence diagram of the changes in this PR.
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration File (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.