1use gcmodule::Trace;2use rustc_hash::FxHashMap;3use serde::{Deserialize, Serialize};4use std::{5 cell::RefCell,6 fmt::{self, Display},7 hash::{BuildHasherDefault, Hash, Hasher},8 ops::Deref,9 rc::Rc,10};1112#[derive(Clone, PartialOrd, Ord, Eq)]13pub struct IStr(Rc<str>);14impl Trace for IStr {15 fn is_type_tracked() -> bool {16 false17 }18}1920impl Deref for IStr {21 type Target = str;2223 fn deref(&self) -> &Self::Target {24 &self.025 }26}2728impl PartialEq for IStr {29 fn eq(&self, other: &Self) -> bool {30 31 Rc::ptr_eq(&self.0, &other.0)32 }33}3435impl PartialEq<str> for IStr {36 fn eq(&self, other: &str) -> bool {37 &self.0 as &str == other38 }39}4041impl Hash for IStr {42 fn hash<H: Hasher>(&self, state: &mut H) {43 state.write_usize(Rc::as_ptr(&self.0) as *const () as usize)44 }45}4647impl Drop for IStr {48 fn drop(&mut self) {49 50 if Rc::strong_count(&self.0) <= 2 {51 let _result = STR_POOL.try_with(|pool| pool.borrow_mut().remove(&self.0));52 }53 }54}5556impl fmt::Debug for IStr {57 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {58 write!(f, "{:?}", &self.0)59 }60}6162impl Display for IStr {63 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {64 f.write_str(&self.0)65 }66}6768thread_local! {69 static STR_POOL: RefCell<FxHashMap<Rc<str>, ()>> = RefCell::new(FxHashMap::with_capacity_and_hasher(200, BuildHasherDefault::default()));70}7172impl From<&str> for IStr {73 fn from(str: &str) -> Self {74 IStr(STR_POOL.with(|pool| {75 let mut pool = pool.borrow_mut();76 if let Some((k, _)) = pool.get_key_value(str) {77 k.clone()78 } else {79 let rc: Rc<str> = str.into();80 pool.insert(rc.clone(), ());81 rc82 }83 }))84 }85}8687impl From<String> for IStr {88 fn from(str: String) -> Self {89 (&str as &str).into()90 }91}9293impl Serialize for IStr {94 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>95 where96 S: serde::Serializer,97 {98 (&self.0 as &str).serialize(serializer)99 }100}101102impl<'de> Deserialize<'de> for IStr {103 fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>104 where105 D: serde::Deserializer<'de>,106 {107 let s = <&str>::deserialize(deserializer)?;108 Ok(s.into())109 }110}