1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
use super::term_weight::TermWeight;
use crate::query::bm25::Bm25Weight;
use crate::query::Weight;
use crate::query::{Explanation, Query};
use crate::schema::IndexRecordOption;
use crate::Searcher;
use crate::Term;
use std::collections::BTreeMap;
use std::fmt;
/// A Term query matches all of the documents
/// containing a specific term.
///
/// The score associated is defined as
/// `idf` * sqrt(`term_freq` / `field norm`)
/// in which :
/// * `idf` - inverse document frequency.
/// * `term_freq` - number of occurrences of the term in the field
/// * `field norm` - number of tokens in the field.
///
/// ```rust
/// use tantivy::collector::{Count, TopDocs};
/// use tantivy::query::TermQuery;
/// use tantivy::schema::{Schema, TEXT, IndexRecordOption};
/// use tantivy::{doc, Index, Term};
/// # fn test() -> tantivy::Result<()> {
/// let mut schema_builder = Schema::builder();
/// let title = schema_builder.add_text_field("title", TEXT);
/// let schema = schema_builder.build();
/// let index = Index::create_in_ram(schema);
/// {
/// let mut index_writer = index.writer(3_000_000)?;
/// index_writer.add_document(doc!(
/// title => "The Name of the Wind",
/// ));
/// index_writer.add_document(doc!(
/// title => "The Diary of Muadib",
/// ));
/// index_writer.add_document(doc!(
/// title => "A Dairy Cow",
/// ));
/// index_writer.add_document(doc!(
/// title => "The Diary of a Young Girl",
/// ));
/// index_writer.commit()?;
/// }
/// let reader = index.reader()?;
/// let searcher = reader.searcher();
/// let query = TermQuery::new(
/// Term::from_field_text(title, "diary"),
/// IndexRecordOption::Basic,
/// );
/// let (top_docs, count) = searcher.search(&query, &(TopDocs::with_limit(2), Count))?;
/// assert_eq!(count, 2);
/// Ok(())
/// # }
/// # assert!(test().is_ok());
/// ```
#[derive(Clone)]
pub struct TermQuery {
term: Term,
index_record_option: IndexRecordOption,
}
impl fmt::Debug for TermQuery {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "TermQuery({:?})", self.term)
}
}
impl TermQuery {
/// Creates a new term query.
pub fn new(term: Term, segment_postings_options: IndexRecordOption) -> TermQuery {
TermQuery {
term,
index_record_option: segment_postings_options,
}
}
/// The `Term` this query is built out of.
pub fn term(&self) -> &Term {
&self.term
}
/// Returns a weight object.
///
/// While `.weight(...)` returns a boxed trait object,
/// this method return a specific implementation.
/// This is useful for optimization purpose.
pub fn specialized_weight(
&self,
searcher: &Searcher,
scoring_enabled: bool,
) -> crate::Result<TermWeight> {
let term = self.term.clone();
let field_entry = searcher.schema().get_field_entry(term.field());
if !field_entry.is_indexed() {
return Err(crate::TantivyError::SchemaError(format!(
"Field {:?} is not indexed",
field_entry.name()
)));
}
let bm25_weight;
if scoring_enabled {
bm25_weight = Bm25Weight::for_terms(searcher, &[term])?;
} else {
bm25_weight =
Bm25Weight::new(Explanation::new("<no score>".to_string(), 1.0f32), 1.0f32);
}
let index_record_option = if scoring_enabled {
self.index_record_option
} else {
IndexRecordOption::Basic
};
Ok(TermWeight::new(
self.term.clone(),
index_record_option,
bm25_weight,
scoring_enabled,
))
}
}
impl Query for TermQuery {
fn weight(&self, searcher: &Searcher, scoring_enabled: bool) -> crate::Result<Box<dyn Weight>> {
Ok(Box::new(
self.specialized_weight(searcher, scoring_enabled)?,
))
}
fn query_terms(&self, terms: &mut BTreeMap<Term, bool>) {
terms.insert(self.term.clone(), false);
}
}