Struct tantivy::fastfield::MultiValuedFastFieldWriter

pub struct MultiValuedFastFieldWriter { /* private fields */ }

Writer for multi-valued (as in, more than one value per document) int fast field.

This Writer is only useful for advanced users. The normal way to get your multivalued int in your index is to

• declare your field with fast set to Cardinality::MultiValues in your schema
• add your document simply by calling .add_document(...).

The MultiValuedFastFieldWriter can be acquired from the fastfield writer, by calling [.get_multivalue_writer_mut(...)](./struct.FastFieldsWriter.html#method. get_multivalue_writer_mut).

Once acquired, writing is done by calling .add_document_vals(&[u64]) once per document.

The serializer makes it possible to remap all of the values that were pushed to the writer using a mapping. This makes it possible to push unordered term ids, during indexing and remap them to their respective term ids when the segment is getting serialized.

Implementations

impl MultiValuedFastFieldWriter

pub fn mem_usage(&self) -> usize

The memory used (inclusive childs)

pub fn field(&self) -> Field

Access the field associated to the MultiValuedFastFieldWriter

pub fn add_document(&mut self, doc: &Document)

Shift to the next document and adds all of the matching field values present in the document.

pub fn add_document_vals(&mut self, vals: &[u64]) -> DocId

Register all of the values associated to a document.

The method returns the DocId of the document that was just written.

pub fn serialize(
    &self,
    serializer: &mut CompositeFastFieldSerializer,
    mapping_opt: Option<&FnvHashMap<u64, TermOrdinal>>,
    doc_id_map: Option<&DocIdMapping>
) -> Result<()>

Serializes fast field values by pushing them to the FastFieldSerializer.

If a mapping is given, the values are remapped and sorted before serialization. This is used when serializing facets. Specifically their terms are first stored in the writer as their position in the IndexWriter’s HashMap. This value is called an UnorderedTermId.

During the serialization of the segment, terms gets sorted and tantivy builds a mapping to convert this UnorderedTermId into term ordinals.