49 lines
1.3 KiB
Rust
49 lines
1.3 KiB
Rust
//! Symbol interner for proc-macro-srv
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use std::{cell::RefCell, collections::HashMap, thread::LocalKey};
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use tt::SmolStr;
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thread_local! {
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pub(crate) static SYMBOL_INTERNER: RefCell<SymbolInterner> = Default::default();
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}
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// ID for an interned symbol.
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#[derive(Hash, Eq, PartialEq, Copy, Clone)]
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pub struct Symbol(u32);
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pub(crate) type SymbolInternerRef = &'static LocalKey<RefCell<SymbolInterner>>;
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impl Symbol {
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pub(super) fn intern(interner: SymbolInternerRef, data: &str) -> Symbol {
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interner.with(|i| i.borrow_mut().intern(data))
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}
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pub(super) fn text(&self, interner: SymbolInternerRef) -> SmolStr {
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interner.with(|i| i.borrow().get(self).clone())
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}
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}
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#[derive(Default)]
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pub(crate) struct SymbolInterner {
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idents: HashMap<SmolStr, u32>,
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ident_data: Vec<SmolStr>,
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}
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impl SymbolInterner {
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fn intern(&mut self, data: &str) -> Symbol {
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if let Some(index) = self.idents.get(data) {
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return Symbol(*index);
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}
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let index = self.idents.len() as u32;
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let data = SmolStr::from(data);
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self.ident_data.push(data.clone());
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self.idents.insert(data, index);
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Symbol(index)
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}
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fn get(&self, sym: &Symbol) -> &SmolStr {
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&self.ident_data[sym.0 as usize]
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}
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}
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