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Merge #7257

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7257: vfs documentation r=matklad a=arnaudgolfouse

This documents every item in the `vfs` crate, except for a few private, windows-specific items.

Co-authored-by: Arnaud <arnaud.golfouse@free.fr>
This commit is contained in:
bors[bot] 2021-01-14 10:13:57 +00:00 committed by GitHub
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6 changed files with 321 additions and 4 deletions
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10
crates/vfs/src/anchored_path.rs
View File

@ -26,14 +26,24 @@
//! from the anchor than.
use crate::FileId;
/// Path relative to a file.
///
/// Owned version of [`AnchoredPath`].
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct AnchoredPathBuf {
/// File that this path is relative to.
pub anchor: FileId,
/// Path relative to `anchor`'s containing directory.
pub path: String,
}
/// Path relative to a file.
///
/// Borrowed version of [`AnchoredPathBuf`].
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
pub struct AnchoredPath<'a> {
/// File that this path is relative to.
pub anchor: FileId,
/// Path relative to `anchor`'s containing directory.
pub path: &'a str,
}

57
crates/vfs/src/file_set.rs
View File

@ -9,6 +9,7 @@ use rustc_hash::FxHashMap;
use crate::{AnchoredPath, FileId, Vfs, VfsPath};
/// A set of [`VfsPath`]s identified by [`FileId`]s.
#[derive(Default, Clone, Eq, PartialEq)]
pub struct FileSet {
files: FxHashMap<VfsPath, FileId>,
@ -16,9 +17,15 @@ pub struct FileSet {
}
impl FileSet {
/// Returns the number of stored paths.
pub fn len(&self) -> usize {
self.files.len()
}
/// Get the id of the file corresponding to `path`.
///
/// If either `path`'s [`anchor`](AnchoredPath::anchor) or the resolved path is not in
/// the set, returns [`None`].
pub fn resolve_path(&self, path: AnchoredPath<'_>) -> Option<FileId> {
let mut base = self.paths[&path.anchor].clone();
base.pop();
@ -26,19 +33,26 @@ impl FileSet {
self.files.get(&path).copied()
}
/// Get the id corresponding to `path` if it exists in the set.
pub fn file_for_path(&self, path: &VfsPath) -> Option<&FileId> {
self.files.get(path)
}
/// Get the path corresponding to `file` if it exists in the set.
pub fn path_for_file(&self, file: &FileId) -> Option<&VfsPath> {
self.paths.get(file)
}
/// Insert the `file_id, path` pair into the set.
///
/// # Note
/// Multiple [`FileId`] can be mapped to the same [`VfsPath`], and vice-versa.
pub fn insert(&mut self, file_id: FileId, path: VfsPath) {
self.files.insert(path.clone(), file_id);
self.paths.insert(file_id, path);
}
/// Iterate over this set's ids.
pub fn iter(&self) -> impl Iterator<Item = FileId> + '_ {
self.paths.keys().copied()
}
@ -50,9 +64,31 @@ impl fmt::Debug for FileSet {
}
}
/// This contains path prefixes to partition a [`Vfs`] into [`FileSet`]s.
///
/// # Example
/// ```rust
/// # use vfs::{file_set::FileSetConfigBuilder, VfsPath, Vfs};
/// let mut builder = FileSetConfigBuilder::default();
/// builder.add_file_set(vec![VfsPath::new_virtual_path("/src".to_string())]);
/// let config = builder.build();
/// let mut file_system = Vfs::default();
/// file_system.set_file_contents(VfsPath::new_virtual_path("/src/main.rs".to_string()), Some(vec![]));
/// file_system.set_file_contents(VfsPath::new_virtual_path("/src/lib.rs".to_string()), Some(vec![]));
/// file_system.set_file_contents(VfsPath::new_virtual_path("/build.rs".to_string()), Some(vec![]));
/// // contains the sets :
/// // { "/src/main.rs", "/src/lib.rs" }
/// // { "build.rs" }
/// let sets = config.partition(&file_system);
/// ```
#[derive(Debug)]
pub struct FileSetConfig {
/// Number of sets that `self` can partition a [`Vfs`] into.
///
/// This should be the number of sets in `self.map` + 1 for files that don't fit in any
/// defined set.
n_file_sets: usize,
/// Map from encoded paths to the set they belong to.
map: fst::Map<Vec<u8>>,
}
@ -63,9 +99,14 @@ impl Default for FileSetConfig {
}
impl FileSetConfig {
/// Returns a builder for `FileSetConfig`.
pub fn builder() -> FileSetConfigBuilder {
FileSetConfigBuilder::default()
}
/// Partition `vfs` into `FileSet`s.
///
/// Creates a new [`FileSet`] for every set of prefixes in `self`.
pub fn partition(&self, vfs: &Vfs) -> Vec<FileSet> {
let mut scratch_space = Vec::new();
let mut res = vec![FileSet::default(); self.len()];
@ -75,9 +116,15 @@ impl FileSetConfig {
}
res
}
/// Number of sets that `self` can partition a [`Vfs`] into.
fn len(&self) -> usize {
self.n_file_sets
}
/// Returns the set index for the given `path`.
///
/// `scratch_space` is used as a buffer and will be entirely replaced.
fn classify(&self, path: &VfsPath, scratch_space: &mut Vec<u8>) -> usize {
scratch_space.clear();
path.encode(scratch_space);
@ -91,6 +138,7 @@ impl FileSetConfig {
}
}
/// Builder for [`FileSetConfig`].
pub struct FileSetConfigBuilder {
roots: Vec<Vec<VfsPath>>,
}
@ -102,12 +150,17 @@ impl Default for FileSetConfigBuilder {
}
impl FileSetConfigBuilder {
/// Returns the number of sets currently held.
pub fn len(&self) -> usize {
self.roots.len()
}
/// Add a new set of paths prefixes.
pub fn add_file_set(&mut self, roots: Vec<VfsPath>) {
self.roots.push(roots)
}
/// Build the `FileSetConfig`.
pub fn build(self) -> FileSetConfig {
let n_file_sets = self.roots.len() + 1;
let map = {
@ -127,11 +180,15 @@ impl FileSetConfigBuilder {
}
}
/// Implements [`fst::Automaton`]
///
/// It will match if `prefix_of` is a prefix of the given data.
struct PrefixOf<'a> {
prefix_of: &'a [u8],
}
impl<'a> PrefixOf<'a> {
/// Creates a new `PrefixOf` from the given slice.
fn new(prefix_of: &'a [u8]) -> Self {
Self { prefix_of }
}

70
crates/vfs/src/lib.rs
View File

@ -53,9 +53,15 @@ pub use crate::{
};
pub use paths::{AbsPath, AbsPathBuf};
/// Handle to a file in [`Vfs`]
///
/// Most functions in rust-analyzer use this when they need to refer to a file.
#[derive(Copy, Clone, Debug, Ord, PartialOrd, Eq, PartialEq, Hash)]
pub struct FileId(pub u32);
/// Storage for all files read by rust-analyzer.
///
/// For more informations see the [crate-level](crate) documentation.
#[derive(Default)]
pub struct Vfs {
interner: PathInterner,
@ -63,40 +69,73 @@ pub struct Vfs {
changes: Vec<ChangedFile>,
}
/// Changed file in the [`Vfs`].
pub struct ChangedFile {
/// Id of the changed file
pub file_id: FileId,
/// Kind of change
pub change_kind: ChangeKind,
}
impl ChangedFile {
/// Returns `true` if the change is not [`Delete`](ChangeKind::Delete).
pub fn exists(&self) -> bool {
self.change_kind != ChangeKind::Delete
}
/// Returns `true` if the change is [`Create`](ChangeKind::Create) or
/// [`Delete`](ChangeKind::Delete).
pub fn is_created_or_deleted(&self) -> bool {
matches!(self.change_kind, ChangeKind::Create | ChangeKind::Delete)
}
}
/// Kind of [file change](ChangedFile).
#[derive(Eq, PartialEq, Copy, Clone, Debug)]
pub enum ChangeKind {
/// The file was (re-)created
Create,
/// The file was modified
Modify,
/// The file was deleted
Delete,
}
impl Vfs {
/// Amount of files currently stored.
///
/// Note that this includes deleted files.
pub fn len(&self) -> usize {
self.data.len()
}
/// Id of the given path if it exists in the `Vfs` and is not deleted.
pub fn file_id(&self, path: &VfsPath) -> Option<FileId> {
self.interner.get(path).filter(|&it| self.get(it).is_some())
}
/// File path corresponding to the given `file_id`.
///
/// # Panics
///
/// Panics if the id is not present in the `Vfs`.
pub fn file_path(&self, file_id: FileId) -> VfsPath {
self.interner.lookup(file_id).clone()
}
/// File content corresponding to the given `file_id`.
///
/// # Panics
///
/// Panics if the id is not present in the `Vfs`, or if the corresponding file is
/// deleted.
pub fn file_contents(&self, file_id: FileId) -> &[u8] {
self.get(file_id).as_deref().unwrap()
}
/// Returns an iterator over the stored ids and their corresponding paths.
///
/// This will skip deleted files.
pub fn iter(&self) -> impl Iterator<Item = (FileId, &VfsPath)> + '_ {
(0..self.data.len())
.map(|it| FileId(it as u32))
@ -106,6 +145,13 @@ impl Vfs {
(file_id, path)
})
}
/// Update the `path` with the given `contents`. `None` means the file was deleted.
///
/// Returns `true` if the file was modified, and saves the [change](ChangedFile).
///
/// If the path does not currently exists in the `Vfs`, allocates a new
/// [`FileId`] for it.
pub fn set_file_contents(&mut self, path: VfsPath, contents: Option<Vec<u8>>) -> bool {
let file_id = self.alloc_file_id(path);
let change_kind = match (&self.get(file_id), &contents) {
@ -120,12 +166,24 @@ impl Vfs {
self.changes.push(ChangedFile { file_id, change_kind });
true
}
/// Returns `true` if the `Vfs` contains [changes](ChangedFile).
pub fn has_changes(&self) -> bool {
!self.changes.is_empty()
}
/// Drain and returns all the changes in the `Vfs`.
pub fn take_changes(&mut self) -> Vec<ChangedFile> {
mem::take(&mut self.changes)
}
/// Returns the id associated with `path`
///
/// - If `path` does not exists in the `Vfs`, allocate a new id for it, associated with a
/// deleted file;
/// - Else, returns `path`'s id.
///
/// Does not record a change.
fn alloc_file_id(&mut self, path: VfsPath) -> FileId {
let file_id = self.interner.intern(path);
let idx = file_id.0 as usize;
@ -133,9 +191,21 @@ impl Vfs {
self.data.resize_with(len, || None);
file_id
}
/// Returns the content associated with the given `file_id`.
///
/// # Panics
///
/// Panics if no file is associated to that id.
fn get(&self, file_id: FileId) -> &Option<Vec<u8>> {
&self.data[file_id.0 as usize]
}
/// Mutably returns the content associated with the given `file_id`.
///
/// # Panics
///
/// Panics if no file is associated to that id.
fn get_mut(&mut self, file_id: FileId) -> &mut Option<Vec<u8>> {
&mut self.data[file_id.0 as usize]
}

80
crates/vfs/src/loader.rs
View File

@ -3,9 +3,12 @@ use std::fmt;
use paths::{AbsPath, AbsPathBuf};
/// A set of files on the file system.
#[derive(Debug, Clone)]
pub enum Entry {
/// The `Entry` is represented by a raw set of files.
Files(Vec<AbsPathBuf>),
/// The `Entry` is represented by `Directories`.
Directories(Directories),
}
@ -17,6 +20,8 @@ pub enum Entry {
/// * it is not under `exclude` path
///
/// If many include/exclude paths match, the longest one wins.
///
/// If a path is in both `include` and `exclude`, the `exclude` one wins.
#[derive(Debug, Clone, Default)]
pub struct Directories {
pub extensions: Vec<String>,
@ -24,45 +29,99 @@ pub struct Directories {
pub exclude: Vec<AbsPathBuf>,
}
/// [`Handle`]'s configuration.
#[derive(Debug)]
pub struct Config {
/// Set of initially loaded files.
pub load: Vec<Entry>,
/// Index of watched entries in `load`.
///
/// If a path in a watched entry is modified,the [`Handle`] should notify it.
pub watch: Vec<usize>,
}
/// Message about an action taken by a [`Handle`].
pub enum Message {
/// Indicate a gradual progress.
///
/// This is supposed to be the number of loaded files.
Progress { n_total: usize, n_done: usize },
/// The handle loaded the following files' content.
Loaded { files: Vec<(AbsPathBuf, Option<Vec<u8>>)> },
}
/// Type that will receive [`Messages`](Message) from a [`Handle`].
pub type Sender = Box<dyn Fn(Message) + Send>;
/// Interface for reading and watching files.
pub trait Handle: fmt::Debug {
/// Spawn a new handle with the given `sender`.
fn spawn(sender: Sender) -> Self
where
Self: Sized;
/// Set this handle's configuration.
fn set_config(&mut self, config: Config);
/// The file's content at `path` has been modified, and should be reloaded.
fn invalidate(&mut self, path: AbsPathBuf);
/// Load the content of the given file, returning [`None`] if it does not
/// exists.
fn load_sync(&mut self, path: &AbsPath) -> Option<Vec<u8>>;
}
impl Entry {
/// Returns:
/// ```text
/// Entry::Directories(Directories {
/// extensions: ["rs"],
/// include: [base],
/// exclude: [base/.git],
/// })
/// ```
pub fn rs_files_recursively(base: AbsPathBuf) -> Entry {
Entry::Directories(dirs(base, &[".git"]))
}
/// Returns:
/// ```text
/// Entry::Directories(Directories {
/// extensions: ["rs"],
/// include: [base],
/// exclude: [base/.git, base/target],
/// })
/// ```
pub fn local_cargo_package(base: AbsPathBuf) -> Entry {
Entry::Directories(dirs(base, &[".git", "target"]))
}
/// Returns:
/// ```text
/// Entry::Directories(Directories {
/// extensions: ["rs"],
/// include: [base],
/// exclude: [base/.git, /tests, /examples, /benches],
/// })
/// ```
pub fn cargo_package_dependency(base: AbsPathBuf) -> Entry {
Entry::Directories(dirs(base, &[".git", "/tests", "/examples", "/benches"]))
}
/// Returns `true` if `path` is included in `self`.
///
/// See [`Directories::contains_file`].
pub fn contains_file(&self, path: &AbsPath) -> bool {
match self {
Entry::Files(files) => files.iter().any(|it| it == path),
Entry::Directories(dirs) => dirs.contains_file(path),
}
}
/// Returns `true` if `path` is included in `self`.
///
/// - If `self` is `Entry::Files`, returns `false`
/// - Else, see [`Directories::contains_dir`].
pub fn contains_dir(&self, path: &AbsPath) -> bool {
match self {
Entry::Files(_) => false,
@ -72,6 +131,7 @@ impl Entry {
}
impl Directories {
/// Returns `true` if `path` is included in `self`.
pub fn contains_file(&self, path: &AbsPath) -> bool {
let ext = path.extension().unwrap_or_default();
if self.extensions.iter().all(|it| it.as_str() != ext) {
@ -79,9 +139,21 @@ impl Directories {
}
self.includes_path(path)
}
/// Returns `true` if `path` is included in `self`.
///
/// Since `path` is supposed to be a directory, this will not take extension
/// into account.
pub fn contains_dir(&self, path: &AbsPath) -> bool {
self.includes_path(path)
}
/// Returns `true` if `path` is included in `self`.
///
/// It is included if
/// - An element in `self.include` is a prefix of `path`.
/// - This path is longer than any element in `self.exclude` that is a prefix
/// of `path`. In case of equality, exclusion wins.
fn includes_path(&self, path: &AbsPath) -> bool {
let mut include: Option<&AbsPathBuf> = None;
for incl in &self.include {
@ -105,6 +177,14 @@ impl Directories {
}
}
/// Returns :
/// ```text
/// Directories {
/// extensions: ["rs"],
/// include: [base],
/// exclude: [base/<exclude>],
/// }
/// ```
fn dirs(base: AbsPathBuf, exclude: &[&str]) -> Directories {
let exclude = exclude.iter().map(|it| base.join(it)).collect::<Vec<_>>();
Directories { extensions: vec!["rs".to_string()], include: vec![base], exclude }

14
crates/vfs/src/path_interner.rs
View File

@ -5,6 +5,7 @@ use rustc_hash::FxHashMap;
use crate::{FileId, VfsPath};
/// Structure to map between [`VfsPath`] and [`FileId`].
#[derive(Default)]
pub(crate) struct PathInterner {
map: FxHashMap<VfsPath, FileId>,
@ -12,9 +13,17 @@ pub(crate) struct PathInterner {
}
impl PathInterner {
/// Get the id corresponding to `path`.
///
/// If `path` does not exists in `self`, returns [`None`].
pub(crate) fn get(&self, path: &VfsPath) -> Option<FileId> {
self.map.get(path).copied()
}
/// Insert `path` in `self`.
///
/// - If `path` already exists in `self`, returns its associated id;
/// - Else, returns a newly allocated id.
pub(crate) fn intern(&mut self, path: VfsPath) -> FileId {
if let Some(id) = self.get(&path) {
return id;
@ -25,6 +34,11 @@ impl PathInterner {
id
}
/// Returns the path corresponding to `id`.
///
/// # Panics
///
/// Panics if `id` does not exists in `self`.
pub(crate) fn lookup(&self, id: FileId) -> &VfsPath {
&self.vec[id.0 as usize]
}

94
crates/vfs/src/vfs_path.rs
View File

@ -3,25 +3,37 @@ use std::fmt;
use paths::{AbsPath, AbsPathBuf};
/// Path in [`Vfs`].
///
/// Long-term, we want to support files which do not reside in the file-system,
/// so we treat VfsPaths as opaque identifiers.
/// so we treat `VfsPath`s as opaque identifiers.
///
/// [`Vfs`]: crate::Vfs
#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
pub struct VfsPath(VfsPathRepr);
impl VfsPath {
/// Creates an "in-memory" path from `/`-separates string.
/// Creates an "in-memory" path from `/`-separated string.
///
/// This is most useful for testing, to avoid windows/linux differences
///
/// # Panics
///
/// Panics if `path` does not start with `'/'`.
pub fn new_virtual_path(path: String) -> VfsPath {
assert!(path.starts_with('/'));
VfsPath(VfsPathRepr::VirtualPath(VirtualPath(path)))
}
/// Returns the `AbsPath` representation of `self` if `self` is on the file system.
pub fn as_path(&self) -> Option<&AbsPath> {
match &self.0 {
VfsPathRepr::PathBuf(it) => Some(it.as_path()),
VfsPathRepr::VirtualPath(_) => None,
}
}
/// Creates a new `VfsPath` with `path` adjoined to `self`.
pub fn join(&self, path: &str) -> Option<VfsPath> {
match &self.0 {
VfsPathRepr::PathBuf(it) => {
@ -34,12 +46,30 @@ impl VfsPath {
}
}
}
/// Remove the last component of `self` if there is one.
///
/// If `self` has no component, returns `false`; else returns `true`.
///
/// # Example
///
/// ```
/// # use vfs::{AbsPathBuf, VfsPath};
/// let mut path = VfsPath::from(AbsPathBuf::assert("/foo/bar".into()));
/// assert!(path.pop());
/// assert_eq!(path, VfsPath::from(AbsPathBuf::assert("/foo".into())));
/// assert!(path.pop());
/// assert_eq!(path, VfsPath::from(AbsPathBuf::assert("/".into())));
/// assert!(!path.pop());
/// ```
pub fn pop(&mut self) -> bool {
match &mut self.0 {
VfsPathRepr::PathBuf(it) => it.pop(),
VfsPathRepr::VirtualPath(it) => it.pop(),
}
}
/// Returns `true` if `other` is a prefix of `self`.
pub fn starts_with(&self, other: &VfsPath) -> bool {
match (&self.0, &other.0) {
(VfsPathRepr::PathBuf(lhs), VfsPathRepr::PathBuf(rhs)) => lhs.starts_with(rhs),
@ -48,6 +78,10 @@ impl VfsPath {
(VfsPathRepr::VirtualPath(_), _) => false,
}
}
/// Returns the `VfsPath` without its final component, if there is one.
///
/// Returns [`None`] if the path is a root or prefix.
pub fn parent(&self) -> Option<VfsPath> {
let mut parent = self.clone();
if parent.pop() {
@ -57,6 +91,7 @@ impl VfsPath {
}
}
/// Returns `self`'s base name and file extension.
pub fn name_and_extension(&self) -> Option<(&str, Option<&str>)> {
match &self.0 {
VfsPathRepr::PathBuf(p) => Some((
@ -67,7 +102,14 @@ impl VfsPath {
}
}
// Don't make this `pub`
/// **Don't make this `pub`**
///
/// Encode the path in the given buffer.
///
/// The encoding will be `0` if [`AbsPathBuf`], `1` if [`VirtualPath`], followed
/// by `self`'s representation.
///
/// Note that this encoding is dependent on the operating system.
pub(crate) fn encode(&self, buf: &mut Vec<u8>) {
let tag = match &self.0 {
VfsPathRepr::PathBuf(_) => 0,
@ -224,6 +266,7 @@ mod windows_paths {
}
}
/// Internal, private representation of [`VfsPath`].
#[derive(Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
enum VfsPathRepr {
PathBuf(AbsPathBuf),
@ -260,13 +303,34 @@ impl fmt::Debug for VfsPathRepr {
}
}
/// `/`-separated virtual path.
///
/// This is used to describe files that do not reside on the file system.
#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
struct VirtualPath(String);
impl VirtualPath {
/// Returns `true` if `other` is a prefix of `self` (as strings).
fn starts_with(&self, other: &VirtualPath) -> bool {
self.0.starts_with(&other.0)
}
/// Remove the last component of `self`.
///
/// This will find the last `'/'` in `self`, and remove everything after it,
/// including the `'/'`.
///
/// If `self` contains no `'/'`, returns `false`; else returns `true`.
///
/// # Example
///
/// ```rust,ignore
/// let mut path = VirtualPath("/foo/bar".to_string());
/// path.pop();
/// assert_eq!(path.0, "/foo");
/// path.pop();
/// assert_eq!(path.0, "");
/// ```
fn pop(&mut self) -> bool {
let pos = match self.0.rfind('/') {
Some(pos) => pos,
@ -275,6 +339,17 @@ impl VirtualPath {
self.0 = self.0[..pos].to_string();
true
}
/// Append the given *relative* path `path` to `self`.
///
/// This will resolve any leading `"../"` in `path` before appending it.
///
/// Returns [`None`] if `path` has more leading `"../"` than the number of
/// components in `self`.
///
/// # Notes
///
/// In practice, appending here means `self/path` as strings.
fn join(&self, mut path: &str) -> Option<VirtualPath> {
let mut res = self.clone();
while path.starts_with("../") {
@ -287,7 +362,18 @@ impl VirtualPath {
Some(res)
}
pub(crate) fn name_and_extension(&self) -> Option<(&str, Option<&str>)> {
/// Returns `self`'s base name and file extension.
///
/// # Returns
/// - `None` if `self` ends with `"//"`.
/// - `Some((name, None))` if `self`'s base contains no `.`, or only one `.` at
/// the start.
/// - `Some((name, Some(extension))` else.
///
/// # Note
/// The extension will not contains `.`. This means `"/foo/bar.baz.rs"` will
/// return `Some(("bar.baz", Some("rs"))`.
fn name_and_extension(&self) -> Option<(&str, Option<&str>)> {
let file_path = if self.0.ends_with('/') { &self.0[..&self.0.len() - 1] } else { &self.0 };
let file_name = match file_path.rfind('/') {
Some(position) => &file_path[position + 1..],