Fix search highlight for non-unicode chars

The `matching_bytes` function takes a `&Token` now and:
- gets the number of bytes to highlight (unchanged).
- uses `Token.num_graphemes_from_bytes` to get the number of grapheme
  clusters to highlight.

In essence, the `matching_bytes` function returns the number of matching
grapheme clusters instead of bytes. Should this function be renamed
then?

Added proper highlighting in the HTTP UI:
- requires dependency on `unicode-segmentation` to extract grapheme
  clusters from tokens
- `<mark>` tag is put around only the matched part
    - before this change, the entire word was highlighted even if only a
      part of it matched
This commit is contained in:
Samyak S Sarnayak 2021-12-17 22:53:34 +05:30
parent 559e019de1
commit 30247d70cd
No known key found for this signature in database
GPG Key ID: 365873F2F0C6153B
3 changed files with 26 additions and 12 deletions

View File

@ -17,6 +17,7 @@ once_cell = "1.5.2"
rayon = "1.5.0" rayon = "1.5.0"
structopt = { version = "0.3.21", default-features = false, features = ["wrap_help"] } structopt = { version = "0.3.21", default-features = false, features = ["wrap_help"] }
tempfile = "3.2.0" tempfile = "3.2.0"
unicode-segmentation = "1.6.0"
# http server # http server
askama = "0.10.5" askama = "0.10.5"

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@ -34,6 +34,7 @@ use structopt::StructOpt;
use tokio::fs::File as TFile; use tokio::fs::File as TFile;
use tokio::io::AsyncWriteExt; use tokio::io::AsyncWriteExt;
use tokio::sync::broadcast; use tokio::sync::broadcast;
use unicode_segmentation::UnicodeSegmentation;
use warp::filters::ws::Message; use warp::filters::ws::Message;
use warp::http::Response; use warp::http::Response;
use warp::Filter; use warp::Filter;
@ -160,13 +161,21 @@ impl<'a, A: AsRef<[u8]>> Highlighter<'a, A> {
let analyzed = self.analyzer.analyze(&old_string); let analyzed = self.analyzer.analyze(&old_string);
for (word, token) in analyzed.reconstruct() { for (word, token) in analyzed.reconstruct() {
if token.is_word() { if token.is_word() {
let to_highlight = matching_words.matching_bytes(token.text()).is_some(); let chars_to_highlight = matching_words.matching_bytes(&token).unwrap_or(0);
if to_highlight { if chars_to_highlight > 0 {
string.push_str("<mark>") let graphemes = word.graphemes(true);
} let chars = graphemes.clone().into_iter();
string.push_str("<mark>");
string.push_str(
chars.take(chars_to_highlight).collect::<String>().as_str(),
);
string.push_str("</mark>");
let chars = graphemes.into_iter().skip(chars_to_highlight);
string.push_str(chars.collect::<String>().as_str());
} else {
string.push_str(word); string.push_str(word);
if to_highlight {
string.push_str("</mark>")
} }
} else { } else {
string.push_str(word); string.push_str(word);

View File

@ -3,6 +3,7 @@ use std::collections::{BTreeMap, HashSet};
use std::ops::{Index, IndexMut}; use std::ops::{Index, IndexMut};
use levenshtein_automata::{Distance, DFA}; use levenshtein_automata::{Distance, DFA};
use meilisearch_tokenizer::Token;
use super::build_dfa; use super::build_dfa;
use crate::search::query_tree::{Operation, Query}; use crate::search::query_tree::{Operation, Query};
@ -33,15 +34,18 @@ impl MatchingWords {
} }
/// Returns the number of matching bytes if the word matches one of the query words. /// Returns the number of matching bytes if the word matches one of the query words.
pub fn matching_bytes(&self, word_to_highlight: &str) -> Option<usize> { pub fn matching_bytes(&self, word_to_highlight: &Token) -> Option<usize> {
self.dfas.iter().find_map(|(dfa, query_word, typo, is_prefix)| { self.dfas.iter().find_map(|(dfa, query_word, typo, is_prefix)| {
match dfa.eval(word_to_highlight) { match dfa.eval(word_to_highlight.text()) {
Distance::Exact(t) if t <= *typo => { Distance::Exact(t) if t <= *typo => {
if *is_prefix { if *is_prefix {
let len = bytes_to_highlight(word_to_highlight, query_word); let len = bytes_to_highlight(word_to_highlight.text(), query_word);
Some(len) Some(word_to_highlight.num_graphemes_from_bytes(len))
} else { } else {
Some(word_to_highlight.len()) Some(
word_to_highlight
.num_graphemes_from_bytes(word_to_highlight.text().len()),
)
} }
} }
_otherwise => None, _otherwise => None,