mirror of
https://github.com/rojo-rbx/rojo.git
synced 2026-04-23 14:15:24 +00:00
Rename vfs -> memofs across the codebase
This commit is contained in:
Lucien Greathouse
404
memofs/src/lib.rs
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404
memofs/src/lib.rs
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/*!
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Implementation of a virtual filesystem with a configurable backend and file
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watching.
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memofs is currently an unstable minimum viable library. Its primary consumer is
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[Rojo](https://github.com/rojo-rbx/rojo), a build system for Roblox.
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## Current Features
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* API similar to `std::fs`
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* Configurable backends
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* `StdBackend`, which uses `std::fs` and the `notify` crate
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* `NoopBackend`, which always throws errors
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* `InMemoryFs`, a simple in-memory filesystem useful for testing
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## Future Features
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* Hash-based hierarchical memoization keys (hence the name)
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* Configurable caching (write-through, write-around, write-back)
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*/
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mod in_memory_fs;
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mod noop_backend;
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mod snapshot;
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mod std_backend;
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use std::io;
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use std::path::{Path, PathBuf};
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use std::sync::{Arc, Mutex, MutexGuard};
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pub use in_memory_fs::InMemoryFs;
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pub use noop_backend::NoopBackend;
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pub use snapshot::VfsSnapshot;
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pub use std_backend::StdBackend;
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mod sealed {
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use super::*;
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/// Sealing trait for VfsBackend.
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pub trait Sealed {}
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impl Sealed for NoopBackend {}
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impl Sealed for StdBackend {}
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impl Sealed for InMemoryFs {}
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}
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/// Trait that transforms `io::Result<T>` into `io::Result<Option<T>>`.
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///
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/// `Ok(None)` takes the place of IO errors whose `io::ErrorKind` is `NotFound`.
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pub trait IoResultExt<T> {
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fn with_not_found(self) -> io::Result<Option<T>>;
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}
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impl<T> IoResultExt<T> for io::Result<T> {
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fn with_not_found(self) -> io::Result<Option<T>> {
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match self {
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Ok(v) => Ok(Some(v)),
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Err(err) => {
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if err.kind() == io::ErrorKind::NotFound {
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Ok(None)
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} else {
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Err(err)
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}
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}
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}
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}
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}
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/// Backend that can be used to create a `Vfs`.
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///
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/// This trait is sealed and cannot not be implemented outside this crate.
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pub trait VfsBackend: sealed::Sealed + Send + 'static {
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fn read(&mut self, path: &Path) -> io::Result<Vec<u8>>;
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fn write(&mut self, path: &Path, data: &[u8]) -> io::Result<()>;
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fn read_dir(&mut self, path: &Path) -> io::Result<ReadDir>;
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fn metadata(&mut self, path: &Path) -> io::Result<Metadata>;
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fn remove_file(&mut self, path: &Path) -> io::Result<()>;
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fn remove_dir_all(&mut self, path: &Path) -> io::Result<()>;
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fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent>;
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fn watch(&mut self, path: &Path) -> io::Result<()>;
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fn unwatch(&mut self, path: &Path) -> io::Result<()>;
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}
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/// Vfs equivalent to [`std::fs::DirEntry`][std::fs::DirEntry].
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///
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/// [std::fs::DirEntry]: https://doc.rust-lang.org/stable/std/fs/struct.DirEntry.html
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pub struct DirEntry {
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pub(crate) path: PathBuf,
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}
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impl DirEntry {
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pub fn path(&self) -> &Path {
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&self.path
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}
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}
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/// Vfs equivalent to [`std::fs::ReadDir`][std::fs::ReadDir].
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///
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/// [std::fs::ReadDir]: https://doc.rust-lang.org/stable/std/fs/struct.ReadDir.html
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pub struct ReadDir {
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pub(crate) inner: Box<dyn Iterator<Item = io::Result<DirEntry>>>,
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}
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impl Iterator for ReadDir {
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type Item = io::Result<DirEntry>;
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fn next(&mut self) -> Option<Self::Item> {
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self.inner.next()
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}
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}
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/// Vfs equivalent to [`std::fs::Metadata`][std::fs::Metadata].
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///
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/// [std::fs::Metadata]: https://doc.rust-lang.org/stable/std/fs/struct.Metadata.html
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#[derive(Debug)]
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pub struct Metadata {
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pub(crate) is_file: bool,
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}
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impl Metadata {
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pub fn is_file(&self) -> bool {
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self.is_file
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}
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pub fn is_dir(&self) -> bool {
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!self.is_file
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}
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}
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/// Represents an event that a filesystem can raise that might need to be
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/// handled.
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#[derive(Debug)]
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#[non_exhaustive]
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pub enum VfsEvent {
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Create(PathBuf),
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Write(PathBuf),
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Remove(PathBuf),
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}
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/// Contains implementation details of the Vfs, wrapped by `Vfs` and `VfsLock`,
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/// the public interfaces to this type.
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struct VfsInner {
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backend: Box<dyn VfsBackend>,
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}
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impl VfsInner {
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fn read<P: AsRef<Path>>(&mut self, path: P) -> io::Result<Arc<Vec<u8>>> {
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let path = path.as_ref();
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let contents = self.backend.read(path)?;
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self.backend.watch(path)?;
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Ok(Arc::new(contents))
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}
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fn write<P: AsRef<Path>, C: AsRef<[u8]>>(&mut self, path: P, contents: C) -> io::Result<()> {
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let path = path.as_ref();
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let contents = contents.as_ref();
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self.backend.write(path, contents)
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}
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fn read_dir<P: AsRef<Path>>(&mut self, path: P) -> io::Result<ReadDir> {
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let path = path.as_ref();
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let dir = self.backend.read_dir(path)?;
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self.backend.watch(path)?;
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Ok(dir)
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}
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fn remove_file<P: AsRef<Path>>(&mut self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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let _ = self.backend.unwatch(path);
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self.backend.remove_file(path)
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}
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fn remove_dir_all<P: AsRef<Path>>(&mut self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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let _ = self.backend.unwatch(path);
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self.backend.remove_dir_all(path)
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}
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fn metadata<P: AsRef<Path>>(&mut self, path: P) -> io::Result<Metadata> {
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let path = path.as_ref();
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self.backend.metadata(path)
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}
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fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
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self.backend.event_receiver()
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}
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fn commit_event(&mut self, event: &VfsEvent) -> io::Result<()> {
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match event {
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VfsEvent::Remove(path) => {
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let _ = self.backend.unwatch(&path);
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}
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_ => {}
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}
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Ok(())
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}
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}
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/// A virtual filesystem with a configurable backend.
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///
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/// All operations on the Vfs take a lock on an internal backend. For performing
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/// large batches of operations, it might be more performant to call `lock()`
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/// and use [`VfsLock`](struct.VfsLock.html) instead.
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pub struct Vfs {
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inner: Mutex<VfsInner>,
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}
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impl Vfs {
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/// Creates a new `Vfs` with the default backend, `StdBackend`.
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pub fn new_default() -> Self {
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Self::new(StdBackend::new())
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}
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/// Creates a new `Vfs` with the given backend.
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pub fn new<B: VfsBackend>(backend: B) -> Self {
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let lock = VfsInner {
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backend: Box::new(backend),
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};
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Self {
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inner: Mutex::new(lock),
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}
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}
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/// Manually lock the Vfs, useful for large batches of operations.
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pub fn lock(&self) -> VfsLock<'_> {
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VfsLock {
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inner: self.inner.lock().unwrap(),
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}
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}
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/// Read a file from the VFS, or the underlying backend if it isn't
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/// resident.
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///
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/// Roughly equivalent to [`std::fs::read`][std::fs::read].
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///
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/// [std::fs::read]: https://doc.rust-lang.org/stable/std/fs/fn.read.html
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#[inline]
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pub fn read<P: AsRef<Path>>(&self, path: P) -> io::Result<Arc<Vec<u8>>> {
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let path = path.as_ref();
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self.inner.lock().unwrap().read(path)
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}
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/// Write a file to the VFS and the underlying backend.
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///
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/// Roughly equivalent to [`std::fs::write`][std::fs::write].
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///
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/// [std::fs::write]: https://doc.rust-lang.org/stable/std/fs/fn.write.html
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#[inline]
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pub fn write<P: AsRef<Path>, C: AsRef<[u8]>>(&self, path: P, contents: C) -> io::Result<()> {
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let path = path.as_ref();
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let contents = contents.as_ref();
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self.inner.lock().unwrap().write(path, contents)
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}
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/// Read all of the children of a directory.
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///
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/// Roughly equivalent to [`std::fs::read_dir`][std::fs::read_dir].
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///
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/// [std::fs::read_dir]: https://doc.rust-lang.org/stable/std/fs/fn.read_dir.html
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#[inline]
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pub fn read_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<ReadDir> {
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let path = path.as_ref();
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self.inner.lock().unwrap().read_dir(path)
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}
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/// Remove a file.
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///
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/// Roughly equivalent to [`std::fs::remove_file`][std::fs::remove_file].
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///
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/// [std::fs::remove_file]: https://doc.rust-lang.org/stable/std/fs/fn.remove_file.html
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#[inline]
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pub fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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self.inner.lock().unwrap().remove_file(path)
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}
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/// Remove a directory and all of its descendants.
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///
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/// Roughly equivalent to [`std::fs::remove_dir_all`][std::fs::remove_dir_all].
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///
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/// [std::fs::remove_dir_all]: https://doc.rust-lang.org/stable/std/fs/fn.remove_dir_all.html
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#[inline]
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pub fn remove_dir_all<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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self.inner.lock().unwrap().remove_dir_all(path)
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}
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/// Query metadata about the given path.
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///
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/// Roughly equivalent to [`std::fs::metadata`][std::fs::metadata].
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///
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/// [std::fs::metadata]: https://doc.rust-lang.org/stable/std/fs/fn.metadata.html
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#[inline]
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pub fn metadata<P: AsRef<Path>>(&self, path: P) -> io::Result<Metadata> {
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let path = path.as_ref();
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self.inner.lock().unwrap().metadata(path)
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}
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/// Retrieve a handle to the event receiver for this `Vfs`.
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#[inline]
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pub fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
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self.inner.lock().unwrap().event_receiver()
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}
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/// Commit an event to this `Vfs`.
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#[inline]
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pub fn commit_event(&self, event: &VfsEvent) -> io::Result<()> {
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self.inner.lock().unwrap().commit_event(event)
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}
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}
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/// A locked handle to a [`Vfs`](struct.Vfs.html), created by `Vfs::lock`.
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///
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/// Implements roughly the same API as [`Vfs`](struct.Vfs.html).
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pub struct VfsLock<'a> {
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inner: MutexGuard<'a, VfsInner>,
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}
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impl VfsLock<'_> {
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/// Read a file from the VFS, or the underlying backend if it isn't
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/// resident.
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///
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/// Roughly equivalent to [`std::fs::read`][std::fs::read].
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///
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/// [std::fs::read]: https://doc.rust-lang.org/stable/std/fs/fn.read.html
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#[inline]
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pub fn read<P: AsRef<Path>>(&mut self, path: P) -> io::Result<Arc<Vec<u8>>> {
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let path = path.as_ref();
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self.inner.read(path)
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}
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/// Write a file to the VFS and the underlying backend.
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///
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/// Roughly equivalent to [`std::fs::write`][std::fs::write].
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///
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/// [std::fs::write]: https://doc.rust-lang.org/stable/std/fs/fn.write.html
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#[inline]
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pub fn write<P: AsRef<Path>, C: AsRef<[u8]>>(
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&mut self,
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path: P,
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contents: C,
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) -> io::Result<()> {
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let path = path.as_ref();
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let contents = contents.as_ref();
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self.inner.write(path, contents)
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}
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/// Read all of the children of a directory.
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///
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/// Roughly equivalent to [`std::fs::read_dir`][std::fs::read_dir].
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///
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/// [std::fs::read_dir]: https://doc.rust-lang.org/stable/std/fs/fn.read_dir.html
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#[inline]
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pub fn read_dir<P: AsRef<Path>>(&mut self, path: P) -> io::Result<ReadDir> {
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let path = path.as_ref();
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self.inner.read_dir(path)
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}
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/// Remove a file.
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///
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/// Roughly equivalent to [`std::fs::remove_file`][std::fs::remove_file].
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///
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/// [std::fs::remove_file]: https://doc.rust-lang.org/stable/std/fs/fn.remove_file.html
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#[inline]
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pub fn remove_file<P: AsRef<Path>>(&mut self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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self.inner.remove_file(path)
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}
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/// Remove a directory and all of its descendants.
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///
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/// Roughly equivalent to [`std::fs::remove_dir_all`][std::fs::remove_dir_all].
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///
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/// [std::fs::remove_dir_all]: https://doc.rust-lang.org/stable/std/fs/fn.remove_dir_all.html
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#[inline]
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pub fn remove_dir_all<P: AsRef<Path>>(&mut self, path: P) -> io::Result<()> {
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let path = path.as_ref();
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self.inner.remove_dir_all(path)
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}
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/// Query metadata about the given path.
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///
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/// Roughly equivalent to [`std::fs::metadata`][std::fs::metadata].
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///
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/// [std::fs::metadata]: https://doc.rust-lang.org/stable/std/fs/fn.metadata.html
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#[inline]
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pub fn metadata<P: AsRef<Path>>(&mut self, path: P) -> io::Result<Metadata> {
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let path = path.as_ref();
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self.inner.metadata(path)
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}
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/// Retrieve a handle to the event receiver for this `Vfs`.
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#[inline]
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pub fn event_receiver(&self) -> crossbeam_channel::Receiver<VfsEvent> {
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self.inner.event_receiver()
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}
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/// Commit an event to this `Vfs`.
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#[inline]
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pub fn commit_event(&mut self, event: &VfsEvent) -> io::Result<()> {
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self.inner.commit_event(event)
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}
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}
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