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// Copyright 2017 1aim GmbH // // Permission is hereby granted, free of charge, to any person obtaining a copy of // this software and associated documentation files (the "Software"), to deal in // the Software without restriction, including without limitation the rights to // use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies // of the Software, and to permit persons to whom the Software is furnished to do // so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in all // copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE // SOFTWARE. use std::ops::{Deref, DerefMut}; use regex::{Regex, Error}; use lru::LruCache; /// An LRU cache for regular expressions. pub struct Cache(LruCache<String, Regex>); impl Cache { /// Create a new LRU cache with the given size limit. pub fn new(capacity: usize) -> Cache { Cache(LruCache::new(capacity)) } /// Check if the same `Regex` is already present in the cache and return it, /// otherwise tries to create a new one and inserts it into the cache. pub fn compile(&mut self, source: &str) -> Result<&Regex, Error> { if !self.0.contains_key(source) { self.0.insert(source.into(), Regex::new(source)?); } Ok(self.0.get_mut(source).unwrap()) } } impl Deref for Cache { type Target = LruCache<String, Regex>; fn deref(&self) -> &Self::Target { &self.0 } } impl DerefMut for Cache { fn deref_mut(&mut self) -> &mut Self::Target { &mut self.0 } } #[cfg(test)] mod test { use cache::Cache; #[test] fn compile() { let mut cache = Cache::new(100); assert!(cache.compile("[01]2").unwrap().is_match("12")); } }