Struct CrossEncoderEngine 

pub struct CrossEncoderEngine { /* private fields */ }

Cross-encoder reranking engine.

Thread-safe — shared via Arc. Maintains a pool of independent ONNX sessions so concurrent rerank calls never contend on a single mutex.

Implementations

impl CrossEncoderEngine

pub async fn new(cache_dir: Option<String>) -> Result<Self>

Load or download the reranker model.

Downloads Xenova/bge-reranker-base ONNX INT8 model from HuggingFace Hub if not already cached. Builds RERANKER_POOL_SIZE independent sessions.

pub async fn score_pairs( &self, query: &str, passages: &[String], ) -> Result<Vec<f32>>

Score a batch of (query, passage) pairs.

Passages are split into chunks of [RERANKER_CHUNK_SIZE] and dispatched in parallel across the session pool (round-robin). Chunk results are reassembled in input order.

Returns a relevance score in [0, 1] for each passage. Higher scores indicate greater relevance to the query.

pub fn pool_size(&self) -> usize

Number of parallel ONNX sessions in the pool.

Trait Implementations

impl Debug for CrossEncoderEngine

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.