Trait tantivy::collector::Collector

pub trait Collector {
    fn set_segment(
        &mut self, 
        segment_local_id: SegmentLocalId, 
        segment: &SegmentReader
    ) -> Result<()>;
    fn collect(&mut self, doc: DocId, score: Score);
}

Collectors are in charge of collecting and retaining relevant information from the document found and scored by the query.

For instance,

• keeping track of the top 10 best documents
• computing a breakdown over a fast field
• computing the number of documents matching the query

Queries are in charge of pushing the DocSet to the collector.

As they work on multiple segments, they first inform the collector of a change in a segment and then call the collect method to push the document to the collector.

Temporally, our collector will receive calls

• .set_segment(0, segment_reader_0)
• .collect(doc0_of_segment_0)
• .collect(...)
• .collect(last_doc_of_segment_0)
• .set_segment(1, segment_reader_1)
• .collect(doc0_of_segment_1)
• .collect(...)
• .collect(last_doc_of_segment_1)
• ...
• .collect(last_doc_of_last_segment)

Segments are not guaranteed to be visited in any specific order.

Required Methods

fn set_segment(
    &mut self,
    segment_local_id: SegmentLocalId,
    segment: &SegmentReader
) -> Result<()>

set_segment is called before beginning to enumerate on this segment.

fn collect(&mut self, doc: DocId, score: Score)

The query pushes the scored document to the collector via this method.

Implementations on Foreign Types

impl<'a, C: Collector> Collector for &'a mut C

fn set_segment(
    &mut self,
    segment_local_id: SegmentLocalId,
    segment: &SegmentReader
) -> Result<()>

fn collect(&mut self, doc: DocId, score: Score)

The query pushes the scored document to the collector via this method.

Implementors

• impl Collector for CountCollector
• impl<'a> Collector for MultiCollector<'a>
• impl Collector for TopCollector
• impl Collector for FacetCollector