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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
use std::cell::RefCell; use std::collections::hash_map::Entry; use std::collections::HashMap; use std::hash::Hash; use std::rc::{Rc, Weak}; use unic_langid::LanguageIdentifier; pub mod concurrent; pub trait Memoizable { type Args: 'static + Eq + Hash + Clone; type Error; fn construct(lang: LanguageIdentifier, args: Self::Args) -> Result<Self, Self::Error> where Self: std::marker::Sized; } #[derive(Debug)] pub struct IntlLangMemoizer { lang: LanguageIdentifier, map: RefCell<type_map::TypeMap>, } impl IntlLangMemoizer { pub fn new(lang: LanguageIdentifier) -> Self { Self { lang, map: RefCell::new(type_map::TypeMap::new()), } } pub fn with_try_get<I, R, U>(&self, args: I::Args, cb: U) -> Result<R, I::Error> where Self: Sized, I: Memoizable + 'static, U: FnOnce(&I) -> R, { let mut map = self .map .try_borrow_mut() .expect("Cannot use memoizer reentrantly"); let cache = map .entry::<HashMap<I::Args, I>>() .or_insert_with(HashMap::new); let e = match cache.entry(args.clone()) { Entry::Occupied(entry) => entry.into_mut(), Entry::Vacant(entry) => { let val = I::construct(self.lang.clone(), args)?; entry.insert(val) } }; Ok(cb(&e)) } } #[derive(Default)] pub struct IntlMemoizer { map: HashMap<LanguageIdentifier, Weak<IntlLangMemoizer>>, } impl IntlMemoizer { pub fn get_for_lang(&mut self, lang: LanguageIdentifier) -> Rc<IntlLangMemoizer> { match self.map.entry(lang.clone()) { Entry::Vacant(empty) => { let entry = Rc::new(IntlLangMemoizer::new(lang)); empty.insert(Rc::downgrade(&entry)); entry } Entry::Occupied(mut entry) => { if let Some(entry) = entry.get().upgrade() { entry } else { let e = Rc::new(IntlLangMemoizer::new(lang)); entry.insert(Rc::downgrade(&e)); e } } } } } #[cfg(test)] mod tests { use super::*; use fluent_langneg::{negotiate_languages, NegotiationStrategy}; use intl_pluralrules::{PluralCategory, PluralRuleType, PluralRules as IntlPluralRules}; struct PluralRules(pub IntlPluralRules); impl PluralRules { pub fn new( lang: LanguageIdentifier, pr_type: PluralRuleType, ) -> Result<Self, &'static str> { let default_lang: LanguageIdentifier = "en".parse().unwrap(); let pr_lang = negotiate_languages( &[lang], &IntlPluralRules::get_locales(pr_type), Some(&default_lang), NegotiationStrategy::Lookup, )[0] .clone(); Ok(Self(IntlPluralRules::create(pr_lang, pr_type)?)) } } impl Memoizable for PluralRules { type Args = (PluralRuleType,); type Error = &'static str; fn construct(lang: LanguageIdentifier, args: Self::Args) -> Result<Self, Self::Error> { Self::new(lang, args.0) } } #[test] fn it_works() { let lang: LanguageIdentifier = "en".parse().unwrap(); let mut memoizer = IntlMemoizer::default(); { let en_memoizer = memoizer.get_for_lang(lang.clone()); let result = en_memoizer .with_try_get::<PluralRules, _, _>((PluralRuleType::CARDINAL,), |cb| cb.0.select(5)) .unwrap(); assert_eq!(result, Ok(PluralCategory::OTHER)); } { let en_memoizer = memoizer.get_for_lang(lang.clone()); let result = en_memoizer .with_try_get::<PluralRules, _, _>((PluralRuleType::CARDINAL,), |cb| cb.0.select(5)) .unwrap(); assert_eq!(result, Ok(PluralCategory::OTHER)); } } }