rust-analyzer/crates/vfs/src/file_set.rs
2020-09-10 01:42:20 +03:00

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//! Partitions a list of files into disjoint subsets.
//!
//! Files which do not belong to any explicitly configured `FileSet` belong to
//! the default `FileSet`.
use std::fmt;
use fst::{IntoStreamer, Streamer};
use rustc_hash::FxHashMap;
use crate::{FileId, Vfs, VfsPath};
#[derive(Default, Clone, Eq, PartialEq)]
pub struct FileSet {
files: FxHashMap<VfsPath, FileId>,
paths: FxHashMap<FileId, VfsPath>,
}
impl FileSet {
pub fn len(&self) -> usize {
self.files.len()
}
pub fn resolve_path(&self, anchor: FileId, path: &str) -> Option<FileId> {
let mut base = self.paths[&anchor].clone();
base.pop();
let path = base.join(path)?;
self.files.get(&path).copied()
}
pub fn possible_sudmobule_names(&self, module_file: FileId) -> Vec<String> {
let directory_to_look_for_submodules = match self.get_directory_with_submodules(module_file)
{
Some(directory) => directory,
None => return Vec::new(),
};
self.paths
.iter()
.filter_map(|(_, path)| {
if path.parent()? == directory_to_look_for_submodules {
path.file_name_and_extension()
} else {
None
}
})
.filter_map(|file_name_and_extension| match file_name_and_extension {
// TODO kb do not include the module file name itself, if present
// TODO kb wrong resolution for nesСпаted non-file modules (mod tests {mod <|>)
// TODO kb in src/bin when a module is included into another,
// the included file gets "moved" into a directory below and now cannot add any other modules
("mod", Some("rs")) | ("lib", Some("rs")) | ("main", Some("rs")) => None,
(file_name, Some("rs")) => Some(file_name.to_owned()),
(subdirectory_name, None) => {
let mod_rs_path =
directory_to_look_for_submodules.join(subdirectory_name)?.join("mod.rs")?;
if self.files.contains_key(&mod_rs_path) {
Some(subdirectory_name.to_owned())
} else {
None
}
}
_ => None,
})
.collect()
}
fn get_directory_with_submodules(&self, module_file: FileId) -> Option<VfsPath> {
let module_file_path = &self.paths[&module_file];
let module_directory_path = module_file_path.parent()?;
match module_file_path.file_name_and_extension() {
Some(("mod", Some("rs"))) | Some(("lib", Some("rs"))) | Some(("main", Some("rs"))) => {
Some(module_directory_path)
}
Some((regular_rust_file_name, Some("rs"))) => {
if matches!(
(
module_directory_path
.parent()
.as_ref()
.and_then(|path| path.file_name_and_extension()),
module_directory_path.file_name_and_extension(),
),
(Some(("src", None)), Some(("bin", None)))
) {
// files in /src/bin/ can import each other directly
Some(module_directory_path)
} else {
module_directory_path.join(regular_rust_file_name)
}
}
_ => None,
}
}
pub fn insert(&mut self, file_id: FileId, path: VfsPath) {
self.files.insert(path.clone(), file_id);
self.paths.insert(file_id, path);
}
pub fn iter(&self) -> impl Iterator<Item = FileId> + '_ {
self.paths.keys().copied()
}
}
impl fmt::Debug for FileSet {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("FileSet").field("n_files", &self.files.len()).finish()
}
}
#[derive(Debug)]
pub struct FileSetConfig {
n_file_sets: usize,
map: fst::Map<Vec<u8>>,
}
impl Default for FileSetConfig {
fn default() -> Self {
FileSetConfig::builder().build()
}
}
impl FileSetConfig {
pub fn builder() -> FileSetConfigBuilder {
FileSetConfigBuilder::default()
}
pub fn partition(&self, vfs: &Vfs) -> Vec<FileSet> {
let mut scratch_space = Vec::new();
let mut res = vec![FileSet::default(); self.len()];
for (file_id, path) in vfs.iter() {
let root = self.classify(&path, &mut scratch_space);
res[root].insert(file_id, path.clone())
}
res
}
fn len(&self) -> usize {
self.n_file_sets
}
fn classify(&self, path: &VfsPath, scratch_space: &mut Vec<u8>) -> usize {
scratch_space.clear();
path.encode(scratch_space);
let automaton = PrefixOf::new(scratch_space.as_slice());
let mut longest_prefix = self.len() - 1;
let mut stream = self.map.search(automaton).into_stream();
while let Some((_, v)) = stream.next() {
longest_prefix = v as usize;
}
longest_prefix
}
}
pub struct FileSetConfigBuilder {
roots: Vec<Vec<VfsPath>>,
}
impl Default for FileSetConfigBuilder {
fn default() -> Self {
FileSetConfigBuilder { roots: Vec::new() }
}
}
impl FileSetConfigBuilder {
pub fn len(&self) -> usize {
self.roots.len()
}
pub fn add_file_set(&mut self, roots: Vec<VfsPath>) {
self.roots.push(roots)
}
pub fn build(self) -> FileSetConfig {
let n_file_sets = self.roots.len() + 1;
let map = {
let mut entries = Vec::new();
for (i, paths) in self.roots.into_iter().enumerate() {
for p in paths {
let mut buf = Vec::new();
p.encode(&mut buf);
entries.push((buf, i as u64));
}
}
entries.sort();
entries.dedup_by(|(a, _), (b, _)| a == b);
fst::Map::from_iter(entries).unwrap()
};
FileSetConfig { n_file_sets, map }
}
}
struct PrefixOf<'a> {
prefix_of: &'a [u8],
}
impl<'a> PrefixOf<'a> {
fn new(prefix_of: &'a [u8]) -> Self {
Self { prefix_of }
}
}
impl fst::Automaton for PrefixOf<'_> {
type State = usize;
fn start(&self) -> usize {
0
}
fn is_match(&self, &state: &usize) -> bool {
state != !0
}
fn can_match(&self, &state: &usize) -> bool {
state != !0
}
fn accept(&self, &state: &usize, byte: u8) -> usize {
if self.prefix_of.get(state) == Some(&byte) {
state + 1
} else {
!0
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn path_prefix() {
let mut file_set = FileSetConfig::builder();
file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo".into())]);
file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo/bar/baz".into())]);
let file_set = file_set.build();
let mut vfs = Vfs::default();
vfs.set_file_contents(
VfsPath::new_virtual_path("/foo/src/lib.rs".into()),
Some(Vec::new()),
);
vfs.set_file_contents(
VfsPath::new_virtual_path("/foo/src/bar/baz/lib.rs".into()),
Some(Vec::new()),
);
vfs.set_file_contents(
VfsPath::new_virtual_path("/foo/bar/baz/lib.rs".into()),
Some(Vec::new()),
);
vfs.set_file_contents(VfsPath::new_virtual_path("/quux/lib.rs".into()), Some(Vec::new()));
let partition = file_set.partition(&vfs).into_iter().map(|it| it.len()).collect::<Vec<_>>();
assert_eq!(partition, vec![2, 1, 1]);
}
#[test]
fn name_prefix() {
let mut file_set = FileSetConfig::builder();
file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo".into())]);
file_set.add_file_set(vec![VfsPath::new_virtual_path("/foo-things".into())]);
let file_set = file_set.build();
let mut vfs = Vfs::default();
vfs.set_file_contents(
VfsPath::new_virtual_path("/foo/src/lib.rs".into()),
Some(Vec::new()),
);
vfs.set_file_contents(
VfsPath::new_virtual_path("/foo-things/src/lib.rs".into()),
Some(Vec::new()),
);
let partition = file_set.partition(&vfs).into_iter().map(|it| it.len()).collect::<Vec<_>>();
assert_eq!(partition, vec![1, 1, 0]);
}
}