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#[cfg(feature = "with-bytes")] pub mod bytes; #[cfg(feature = "with-futures")] pub mod futures; #[cfg(feature = "with-futures")] pub use crate::futures::IntoFlatten as _; use std::collections::{hash_map::Entry, HashMap}; struct RevPrefixes<'a>(&'a str); impl<'a> Iterator for RevPrefixes<'a> { type Item = &'a str; fn next(&mut self) -> Option<Self::Item> { let cv = self.0; if cv.is_empty() { return None; } if let Some(sep_pos) = cv.rfind("/") { self.0 = &cv[..sep_pos]; } else { self.0 = "" } return Some(cv); } } pub struct PrefixLookupBag<T> { dict: HashMap<String, T>, } impl<T> Default for PrefixLookupBag<T> { fn default() -> Self { PrefixLookupBag { dict: HashMap::new(), } } } impl<T> PrefixLookupBag<T> { #[allow(dead_code)] pub fn get(&self, key: &str) -> Option<&T> { RevPrefixes(key).find_map(|key| self.dict.get(key)) } #[allow(dead_code)] pub fn keys(&self) -> impl Iterator<Item = &String> { self.dict.keys() } pub fn get_mut(&mut self, key: &str) -> Option<&mut T> { if let Some(k) = RevPrefixes(key).find(|&k| self.dict.contains_key(k)) { self.dict.get_mut(k) } else { None } } pub fn insert(&mut self, key: String, v: T) -> Option<T> { self.dict.insert(key, v) } pub fn entry(&mut self, key: String) -> Entry<String, T> { if let Some(k) = RevPrefixes(&key).find(|&k| self.dict.contains_key(k)) { self.dict.entry(k.to_owned()) } else { self.dict.entry(key) } } pub fn remove(&mut self, key: &str) -> Option<T> { self.dict.remove(key) } } #[cfg(test)] mod test { use super::*; #[test] fn test_rev() { let v: Vec<_> = RevPrefixes("/net/0x1212xx/from/0x123/exeunit/exec").collect(); assert_eq!( v, [ "/net/0x1212xx/from/0x123/exeunit/exec", "/net/0x1212xx/from/0x123/exeunit", "/net/0x1212xx/from/0x123", "/net/0x1212xx/from", "/net/0x1212xx", "/net" ] ); let v: Vec<_> = RevPrefixes("").collect(); assert!(v.is_empty()); } #[test] fn test_prefix_bag() { let mut bag = PrefixLookupBag::default(); bag.insert("/ala/ma/kota".into(), 1); bag.insert("/ala/ma/psa".into(), 2); bag.insert("/ala".into(), 7); assert_eq!(bag.get("/ala/ma/smoka"), Some(&7)); assert_eq!(bag.get("/ala/ma/kota"), Some(&1)); assert_eq!(bag.get("/jola/ma/psa"), None); } }