Trait tantivy::query::Query[−][src]

pub trait Query: QueryClone + Send + Sync + Downcast + Debug {
    fn weight(
        &self, 
        searcher: &Searcher, 
        scoring_enabled: bool
    ) -> Result<Box<dyn Weight>>;

    fn explain(
        &self, 
        searcher: &Searcher, 
        doc_address: DocAddress
    ) -> Result<Explanation> { ... }

    fn count(&self, searcher: &Searcher) -> Result<usize> { ... }

    fn query_terms(&self, _term_set: &mut BTreeMap<Term, bool>) { ... }
}
Expand description

The Query trait defines a set of documents and a scoring method for those documents.

The Query trait is in charge of defining :

  • a set of documents
  • a way to score these documents

When performing a search, these documents will then be pushed to a Collector, which will in turn be in charge of deciding what to do with them.

Concretely, this scored docset is represented by the Scorer trait.

Because our index is actually split into segments, the query does not actually directly creates DocSet object. Instead, the query creates a Weight object for a given searcher.

The weight object, in turn, makes it possible to create a scorer for a specific SegmentReader.

So to sum it up :

  • a Query is recipe to define a set of documents as well the way to score them.
  • a Weight is this recipe tied to a specific Searcher. It may for instance hold statistics about the different term of the query. It is created by the query.
  • a Scorer is a cursor over the set of matching documents, for a specific SegmentReader. It is created by the Weight.

When implementing a new type of Query, it is normal to implement a dedicated Query, Weight and Scorer.

Required methods

Create the weight associated to a query.

If scoring is not required, setting scoring_enabled to false can increase performances.

See Weight.

Provided methods

Returns an Explanation for the score of the document.

Returns the number of documents matching the query.

Extract all of the terms associated to the query and insert them in the term set given in arguments.

Each term is associated with a boolean indicating whether Positions are required or not.

Implementations

Returns true if the trait object wraps an object of type __T.

Returns a boxed object from a boxed trait object if the underlying object is of type __T. Returns the original boxed trait if it isn’t.

Returns an Rc-ed object from an Rc-ed trait object if the underlying object is of type __T. Returns the original Rc-ed trait if it isn’t.

Returns a reference to the object within the trait object if it is of type __T, or None if it isn’t.

Returns a mutable reference to the object within the trait object if it is of type __T, or None if it isn’t.

Implementations on Foreign Types

Implementors