mirror of
https://github.com/rust-lang/rust-analyzer
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43 lines
1.3 KiB
Rust
43 lines
1.3 KiB
Rust
//! Maps paths to compact integer ids. We don't care about clearings paths which
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//! no longer exist -- the assumption is total size of paths we ever look at is
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//! not too big.
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use std::hash::BuildHasherDefault;
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use indexmap::IndexSet;
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use rustc_hash::FxHasher;
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use crate::{FileId, VfsPath};
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/// Structure to map between [`VfsPath`] and [`FileId`].
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#[derive(Default)]
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pub(crate) struct PathInterner {
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map: IndexSet<VfsPath, BuildHasherDefault<FxHasher>>,
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}
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impl PathInterner {
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/// Get the id corresponding to `path`.
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///
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/// If `path` does not exists in `self`, returns [`None`].
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pub(crate) fn get(&self, path: &VfsPath) -> Option<FileId> {
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self.map.get_index_of(path).map(|i| FileId(i as u32))
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}
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/// Insert `path` in `self`.
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///
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/// - If `path` already exists in `self`, returns its associated id;
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/// - Else, returns a newly allocated id.
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pub(crate) fn intern(&mut self, path: VfsPath) -> FileId {
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let (id, _added) = self.map.insert_full(path);
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assert!(id < u32::MAX as usize);
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FileId(id as u32)
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}
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/// Returns the path corresponding to `id`.
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///
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/// # Panics
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///
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/// Panics if `id` does not exists in `self`.
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pub(crate) fn lookup(&self, id: FileId) -> &VfsPath {
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self.map.get_index(id.0 as usize).unwrap()
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}
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}
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