1 //! A type that represents the union of a set of regular expressions. 2 3 use regex::RegexSet as RxSet; 4 use std::cell::Cell; 5 6 /// A dynamic set of regular expressions. 7 #[derive(Debug, Default)] 8 pub struct RegexSet { 9 items: Vec<String>, 10 /// Whether any of the items in the set was ever matched. The length of this 11 /// vector is exactly the length of `items`. 12 matched: Vec<Cell<bool>>, 13 set: Option<RxSet>, 14 /// Whether we should record matching items in the `matched` vector or not. 15 record_matches: bool, 16 } 17 18 impl RegexSet { 19 /// Is this set empty? is_empty(&self) -> bool20 pub fn is_empty(&self) -> bool { 21 self.items.is_empty() 22 } 23 24 /// Insert a new regex into this set. insert<S>(&mut self, string: S) where S: AsRef<str>,25 pub fn insert<S>(&mut self, string: S) 26 where 27 S: AsRef<str>, 28 { 29 self.items.push(string.as_ref().to_owned()); 30 self.matched.push(Cell::new(false)); 31 self.set = None; 32 } 33 34 /// Returns slice of String from its field 'items' get_items(&self) -> &[String]35 pub fn get_items(&self) -> &[String] { 36 &self.items[..] 37 } 38 39 /// Returns an iterator over regexes in the set which didn't match any 40 /// strings yet. unmatched_items(&self) -> impl Iterator<Item = &String>41 pub fn unmatched_items(&self) -> impl Iterator<Item = &String> { 42 self.items.iter().enumerate().filter_map(move |(i, item)| { 43 if !self.record_matches || self.matched[i].get() { 44 return None; 45 } 46 47 Some(item) 48 }) 49 } 50 51 /// Construct a RegexSet from the set of entries we've accumulated. 52 /// 53 /// Must be called before calling `matches()`, or it will always return 54 /// false. build(&mut self, record_matches: bool)55 pub fn build(&mut self, record_matches: bool) { 56 let items = self.items.iter().map(|item| format!("^{}$", item)); 57 self.record_matches = record_matches; 58 self.set = match RxSet::new(items) { 59 Ok(x) => Some(x), 60 Err(e) => { 61 warn!("Invalid regex in {:?}: {:?}", self.items, e); 62 None 63 } 64 } 65 } 66 67 /// Does the given `string` match any of the regexes in this set? matches<S>(&self, string: S) -> bool where S: AsRef<str>,68 pub fn matches<S>(&self, string: S) -> bool 69 where 70 S: AsRef<str>, 71 { 72 let s = string.as_ref(); 73 let set = match self.set { 74 Some(ref set) => set, 75 None => return false, 76 }; 77 78 if !self.record_matches { 79 return set.is_match(s); 80 } 81 82 let matches = set.matches(s); 83 if !matches.matched_any() { 84 return false; 85 } 86 for i in matches.iter() { 87 self.matched[i].set(true); 88 } 89 90 true 91 } 92 } 93