1use gcmodule::Trace;2use rustc_hash::FxHashMap;3use serde::{Deserialize, Serialize};4use std::{5 borrow::Cow,6 cell::RefCell,7 convert::TryFrom,8 fmt::{self, Display},9 hash::{BuildHasherDefault, Hash, Hasher},10 ops::Deref,11 rc::Rc,12 str::Utf8Error,13};1415#[derive(Clone, PartialOrd, Ord, Eq)]16pub struct IStr(Rc<str>);17impl Trace for IStr {18 fn is_type_tracked() -> bool {19 false20 }21}2223impl Deref for IStr {24 type Target = str;2526 fn deref(&self) -> &Self::Target {27 &self.028 }29}3031impl PartialEq for IStr {32 fn eq(&self, other: &Self) -> bool {33 34 Rc::ptr_eq(&self.0, &other.0)35 }36}3738impl PartialEq<str> for IStr {39 fn eq(&self, other: &str) -> bool {40 &self.0 as &str == other41 }42}4344impl Hash for IStr {45 fn hash<H: Hasher>(&self, state: &mut H) {46 state.write_usize(Rc::as_ptr(&self.0) as *const () as usize)47 }48}4950impl Drop for IStr {51 fn drop(&mut self) {52 53 if Rc::strong_count(&self.0) <= 2 {54 let _result = STR_POOL.try_with(|pool| pool.borrow_mut().remove(&self.0));55 }56 }57}5859impl fmt::Debug for IStr {60 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {61 write!(f, "{:?}", &self.0)62 }63}6465impl Display for IStr {66 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {67 f.write_str(&self.0)68 }69}7071thread_local! {72 static STR_POOL: RefCell<FxHashMap<Rc<str>, ()>> = RefCell::new(FxHashMap::with_capacity_and_hasher(200, BuildHasherDefault::default()));73}7475impl From<&str> for IStr {76 fn from(str: &str) -> Self {77 IStr(STR_POOL.with(|pool| {78 let mut pool = pool.borrow_mut();79 if let Some((k, _)) = pool.get_key_value(str) {80 k.clone()81 } else {82 let rc: Rc<str> = str.into();83 pool.insert(rc.clone(), ());84 rc85 }86 }))87 }88}8990impl TryFrom<&[u8]> for IStr {91 type Error = Utf8Error;9293 fn try_from(value: &[u8]) -> Result<Self, Self::Error> {94 let str = std::str::from_utf8(value)?;95 Ok(str.into())96 }97}9899impl From<String> for IStr {100 fn from(str: String) -> Self {101 (&str as &str).into()102 }103}104105impl<'i> From<Cow<'i, str>> for IStr {106 fn from(c: Cow<'i, str>) -> Self {107 (&c as &str).into()108 }109}110111impl Serialize for IStr {112 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>113 where114 S: serde::Serializer,115 {116 (&self.0 as &str).serialize(serializer)117 }118}119120impl<'de> Deserialize<'de> for IStr {121 fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>122 where123 D: serde::Deserializer<'de>,124 {125 let s = <&str>::deserialize(deserializer)?;126 Ok(s.into())127 }128}