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
|
use super::term_weight::TermWeight;
use crate::query::bm25::BM25Weight;
use crate::query::Query;
use crate::query::Weight;
use crate::schema::IndexRecordOption;
use crate::Result;
use crate::Searcher;
use crate::Term;
use std::collections::BTreeSet;
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
/// #[macro_use]
/// extern crate tantivy;
/// use tantivy::schema::{Schema, TEXT, IndexRecordOption};
/// use tantivy::{Index, Result, Term};
/// use tantivy::collector::{Count, TopDocs};
/// use tantivy::query::TermQuery;
///
/// # fn main() { example().unwrap(); }
/// fn example() -> 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)).unwrap();
/// assert_eq!(count, 2);
///
/// 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) -> TermWeight {
let term = self.term.clone();
let bm25_weight = BM25Weight::for_terms(searcher, &[term]);
let index_record_option = if scoring_enabled {
self.index_record_option
} else {
IndexRecordOption::Basic
};
TermWeight::new(self.term.clone(), index_record_option, bm25_weight)
}
}
impl Query for TermQuery {
fn weight(&self, searcher: &Searcher, scoring_enabled: bool) -> Result<Box<dyn Weight>> {
Ok(Box::new(self.specialized_weight(searcher, scoring_enabled)))
}
fn query_terms(&self, term_set: &mut BTreeSet<Term>) {
term_set.insert(self.term.clone());
}
}
|