| //! # Virtual File System |
| //! |
| //! VFS records all file changes pushed to it via [`set_file_contents`]. |
| //! As such it only ever stores changes, not the actual content of a file at any given moment. |
| //! All file changes are logged, and can be retrieved via |
| //! [`take_changes`] method. The pack of changes is then pushed to `salsa` and |
| //! triggers incremental recomputation. |
| //! |
| //! Files in VFS are identified with [`FileId`]s -- interned paths. The notion of |
| //! the path, [`VfsPath`] is somewhat abstract: at the moment, it is represented |
| //! as an [`std::path::PathBuf`] internally, but this is an implementation detail. |
| //! |
| //! VFS doesn't do IO or file watching itself. For that, see the [`loader`] |
| //! module. [`loader::Handle`] is an object-safe trait which abstracts both file |
| //! loading and file watching. [`Handle`] is dynamically configured with a set of |
| //! directory entries which should be scanned and watched. [`Handle`] then |
| //! asynchronously pushes file changes. Directory entries are configured in |
| //! free-form via list of globs, it's up to the [`Handle`] to interpret the globs |
| //! in any specific way. |
| //! |
| //! VFS stores a flat list of files. [`file_set::FileSet`] can partition this list |
| //! of files into disjoint sets of files. Traversal-like operations (including |
| //! getting the neighbor file by the relative path) are handled by the [`FileSet`]. |
| //! [`FileSet`]s are also pushed to salsa and cause it to re-check `mod foo;` |
| //! declarations when files are created or deleted. |
| //! |
| //! [`FileSet`] and [`loader::Entry`] play similar, but different roles. |
| //! Both specify the "set of paths/files", one is geared towards file watching, |
| //! the other towards salsa changes. In particular, single [`FileSet`] |
| //! may correspond to several [`loader::Entry`]. For example, a crate from |
| //! crates.io which uses code generation would have two [`Entries`] -- for sources |
| //! in `~/.cargo`, and for generated code in `./target/debug/build`. It will |
| //! have a single [`FileSet`] which unions the two sources. |
| //! |
| //! [`set_file_contents`]: Vfs::set_file_contents |
| //! [`take_changes`]: Vfs::take_changes |
| //! [`FileSet`]: file_set::FileSet |
| //! [`Handle`]: loader::Handle |
| //! [`Entries`]: loader::Entry |
| |
| #![warn(rust_2018_idioms, unused_lifetimes)] |
| |
| mod anchored_path; |
| pub mod file_set; |
| pub mod loader; |
| mod path_interner; |
| mod vfs_path; |
| |
| use std::{fmt, mem}; |
| |
| use crate::path_interner::PathInterner; |
| |
| pub use crate::{ |
| anchored_path::{AnchoredPath, AnchoredPathBuf}, |
| vfs_path::VfsPath, |
| }; |
| 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(u32); |
| // pub struct FileId(NonMaxU32); |
| |
| impl FileId { |
| /// Think twice about using this outside of tests. If this ends up in a wrong place it will cause panics! |
| // FIXME: To be removed once we get rid of all `SpanData::DUMMY` usages. |
| pub const BOGUS: FileId = FileId(0xe4e4e); |
| pub const MAX_FILE_ID: u32 = 0x7fff_ffff; |
| |
| #[inline] |
| pub const fn from_raw(raw: u32) -> FileId { |
| assert!(raw <= Self::MAX_FILE_ID); |
| FileId(raw) |
| } |
| |
| #[inline] |
| pub fn index(self) -> u32 { |
| self.0 |
| } |
| } |
| |
| /// safe because `FileId` is a newtype of `u32` |
| impl nohash_hasher::IsEnabled for FileId {} |
| |
| /// Storage for all file changes and the file id to path mapping. |
| /// |
| /// For more information see the [crate-level](crate) documentation. |
| #[derive(Default)] |
| pub struct Vfs { |
| interner: PathInterner, |
| data: Vec<FileState>, |
| changes: Vec<ChangedFile>, |
| } |
| |
| #[derive(Copy, PartialEq, PartialOrd, Clone)] |
| pub enum FileState { |
| Exists, |
| Deleted, |
| } |
| |
| /// Changed file in the [`Vfs`]. |
| #[derive(Debug)] |
| pub struct ChangedFile { |
| /// Id of the changed file |
| pub file_id: FileId, |
| /// Kind of change |
| pub change: Change, |
| } |
| |
| impl ChangedFile { |
| /// Returns `true` if the change is not [`Delete`](ChangeKind::Delete). |
| pub fn exists(&self) -> bool { |
| !matches!(self.change, Change::Delete) |
| } |
| |
| /// Returns `true` if the change is [`Create`](ChangeKind::Create) or |
| /// [`Delete`](Change::Delete). |
| pub fn is_created_or_deleted(&self) -> bool { |
| matches!(self.change, Change::Create(_) | Change::Delete) |
| } |
| |
| pub fn kind(&self) -> ChangeKind { |
| match self.change { |
| Change::Create(_) => ChangeKind::Create, |
| Change::Modify(_) => ChangeKind::Modify, |
| Change::Delete => ChangeKind::Delete, |
| } |
| } |
| } |
| |
| /// Kind of [file change](ChangedFile). |
| #[derive(Eq, PartialEq, Debug)] |
| pub enum Change { |
| /// The file was (re-)created |
| Create(Vec<u8>), |
| /// The file was modified |
| Modify(Vec<u8>), |
| /// The file was deleted |
| Delete, |
| } |
| |
| /// Kind of [file change](ChangedFile). |
| #[derive(Eq, PartialEq, Debug)] |
| pub enum ChangeKind { |
| /// The file was (re-)created |
| Create, |
| /// The file was modified |
| Modify, |
| /// The file was deleted |
| Delete, |
| } |
| |
| impl Vfs { |
| /// 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| matches!(self.get(it), FileState::Exists)) |
| } |
| |
| /// 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() |
| } |
| |
| /// 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)) |
| .filter(move |&file_id| matches!(self.get(file_id), FileState::Exists)) |
| .map(move |file_id| { |
| let path = self.interner.lookup(file_id); |
| (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) { |
| (FileState::Deleted, None) => return false, |
| (FileState::Deleted, Some(v)) => Change::Create(v), |
| (FileState::Exists, None) => Change::Delete, |
| (FileState::Exists, Some(v)) => Change::Modify(v), |
| }; |
| let changed_file = ChangedFile { file_id, change: change_kind }; |
| self.data[file_id.0 as usize] = |
| if changed_file.exists() { FileState::Exists } else { FileState::Deleted }; |
| self.changes.push(changed_file); |
| true |
| } |
| |
| /// Drain and returns all the changes in the `Vfs`. |
| pub fn take_changes(&mut self) -> Vec<ChangedFile> { |
| mem::take(&mut self.changes) |
| } |
| |
| /// Provides a panic-less way to verify file_id validity. |
| pub fn exists(&self, file_id: FileId) -> bool { |
| matches!(self.get(file_id), FileState::Exists) |
| } |
| |
| /// 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; |
| let len = self.data.len().max(idx + 1); |
| self.data.resize(len, FileState::Deleted); |
| file_id |
| } |
| |
| /// Returns the status of the file associated with the given `file_id`. |
| /// |
| /// # Panics |
| /// |
| /// Panics if no file is associated to that id. |
| fn get(&self, file_id: FileId) -> FileState { |
| self.data[file_id.0 as usize] |
| } |
| } |
| |
| impl fmt::Debug for Vfs { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_struct("Vfs").field("n_files", &self.data.len()).finish() |
| } |
| } |