fs.rs

  1use anyhow::{anyhow, Result};
  2use fsevent::EventStream;
  3use futures::{Stream, StreamExt};
  4use smol::io::{AsyncReadExt, AsyncWriteExt};
  5use std::{
  6    io,
  7    os::unix::fs::MetadataExt,
  8    path::{Component, Path, PathBuf},
  9    pin::Pin,
 10    time::{Duration, SystemTime},
 11};
 12use text::Rope;
 13
 14#[async_trait::async_trait]
 15pub trait Fs: Send + Sync {
 16    async fn create_dir(&self, path: &Path) -> Result<()>;
 17    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()>;
 18    async fn rename(&self, source: &Path, target: &Path, options: RenameOptions) -> Result<()>;
 19    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()>;
 20    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()>;
 21    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>>;
 22    async fn load(&self, path: &Path) -> Result<String>;
 23    async fn save(&self, path: &Path, text: &Rope) -> Result<()>;
 24    async fn canonicalize(&self, path: &Path) -> Result<PathBuf>;
 25    async fn is_file(&self, path: &Path) -> bool;
 26    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>>;
 27    async fn read_dir(
 28        &self,
 29        path: &Path,
 30    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>>;
 31    async fn watch(
 32        &self,
 33        path: &Path,
 34        latency: Duration,
 35    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>>;
 36    fn is_fake(&self) -> bool;
 37    #[cfg(any(test, feature = "test-support"))]
 38    fn as_fake(&self) -> &FakeFs;
 39}
 40
 41#[derive(Copy, Clone, Default)]
 42pub struct CreateOptions {
 43    pub overwrite: bool,
 44    pub ignore_if_exists: bool,
 45}
 46
 47#[derive(Copy, Clone, Default)]
 48pub struct RenameOptions {
 49    pub overwrite: bool,
 50    pub ignore_if_exists: bool,
 51}
 52
 53#[derive(Copy, Clone, Default)]
 54pub struct RemoveOptions {
 55    pub recursive: bool,
 56    pub ignore_if_not_exists: bool,
 57}
 58
 59#[derive(Clone, Debug)]
 60pub struct Metadata {
 61    pub inode: u64,
 62    pub mtime: SystemTime,
 63    pub is_symlink: bool,
 64    pub is_dir: bool,
 65}
 66
 67pub struct RealFs;
 68
 69#[async_trait::async_trait]
 70impl Fs for RealFs {
 71    async fn create_dir(&self, path: &Path) -> Result<()> {
 72        Ok(smol::fs::create_dir_all(path).await?)
 73    }
 74
 75    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()> {
 76        let mut open_options = smol::fs::OpenOptions::new();
 77        open_options.write(true).create(true);
 78        if options.overwrite {
 79            open_options.truncate(true);
 80        } else if !options.ignore_if_exists {
 81            open_options.create_new(true);
 82        }
 83        open_options.open(path).await?;
 84        Ok(())
 85    }
 86
 87    async fn rename(&self, source: &Path, target: &Path, options: RenameOptions) -> Result<()> {
 88        if !options.overwrite && smol::fs::metadata(target).await.is_ok() {
 89            if options.ignore_if_exists {
 90                return Ok(());
 91            } else {
 92                return Err(anyhow!("{target:?} already exists"));
 93            }
 94        }
 95
 96        smol::fs::rename(source, target).await?;
 97        Ok(())
 98    }
 99
100    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()> {
101        let result = if options.recursive {
102            smol::fs::remove_dir_all(path).await
103        } else {
104            smol::fs::remove_dir(path).await
105        };
106        match result {
107            Ok(()) => Ok(()),
108            Err(err) if err.kind() == io::ErrorKind::NotFound && options.ignore_if_not_exists => {
109                Ok(())
110            }
111            Err(err) => Err(err)?,
112        }
113    }
114
115    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()> {
116        match smol::fs::remove_file(path).await {
117            Ok(()) => Ok(()),
118            Err(err) if err.kind() == io::ErrorKind::NotFound && options.ignore_if_not_exists => {
119                Ok(())
120            }
121            Err(err) => Err(err)?,
122        }
123    }
124
125    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
126        Ok(Box::new(std::fs::File::open(path)?))
127    }
128
129    async fn load(&self, path: &Path) -> Result<String> {
130        let mut file = smol::fs::File::open(path).await?;
131        let mut text = String::new();
132        file.read_to_string(&mut text).await?;
133        Ok(text)
134    }
135
136    async fn save(&self, path: &Path, text: &Rope) -> Result<()> {
137        let buffer_size = text.summary().bytes.min(10 * 1024);
138        let file = smol::fs::File::create(path).await?;
139        let mut writer = smol::io::BufWriter::with_capacity(buffer_size, file);
140        for chunk in text.chunks() {
141            writer.write_all(chunk.as_bytes()).await?;
142        }
143        writer.flush().await?;
144        Ok(())
145    }
146
147    async fn canonicalize(&self, path: &Path) -> Result<PathBuf> {
148        Ok(smol::fs::canonicalize(path).await?)
149    }
150
151    async fn is_file(&self, path: &Path) -> bool {
152        smol::fs::metadata(path)
153            .await
154            .map_or(false, |metadata| metadata.is_file())
155    }
156
157    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>> {
158        let symlink_metadata = match smol::fs::symlink_metadata(path).await {
159            Ok(metadata) => metadata,
160            Err(err) => {
161                return match (err.kind(), err.raw_os_error()) {
162                    (io::ErrorKind::NotFound, _) => Ok(None),
163                    (io::ErrorKind::Other, Some(libc::ENOTDIR)) => Ok(None),
164                    _ => Err(anyhow::Error::new(err)),
165                }
166            }
167        };
168
169        let is_symlink = symlink_metadata.file_type().is_symlink();
170        let metadata = if is_symlink {
171            smol::fs::metadata(path).await?
172        } else {
173            symlink_metadata
174        };
175        Ok(Some(Metadata {
176            inode: metadata.ino(),
177            mtime: metadata.modified().unwrap(),
178            is_symlink,
179            is_dir: metadata.file_type().is_dir(),
180        }))
181    }
182
183    async fn read_dir(
184        &self,
185        path: &Path,
186    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>> {
187        let result = smol::fs::read_dir(path).await?.map(|entry| match entry {
188            Ok(entry) => Ok(entry.path()),
189            Err(error) => Err(anyhow!("failed to read dir entry {:?}", error)),
190        });
191        Ok(Box::pin(result))
192    }
193
194    async fn watch(
195        &self,
196        path: &Path,
197        latency: Duration,
198    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>> {
199        let (tx, rx) = smol::channel::unbounded();
200        let (stream, handle) = EventStream::new(&[path], latency);
201        std::mem::forget(handle);
202        std::thread::spawn(move || {
203            stream.run(move |events| smol::block_on(tx.send(events)).is_ok());
204        });
205        Box::pin(rx)
206    }
207
208    fn is_fake(&self) -> bool {
209        false
210    }
211    #[cfg(any(test, feature = "test-support"))]
212    fn as_fake(&self) -> &FakeFs {
213        panic!("called `RealFs::as_fake`")
214    }
215}
216
217#[cfg(any(test, feature = "test-support"))]
218#[derive(Clone, Debug)]
219struct FakeFsEntry {
220    metadata: Metadata,
221    content: Option<String>,
222}
223
224#[cfg(any(test, feature = "test-support"))]
225struct FakeFsState {
226    entries: std::collections::BTreeMap<PathBuf, FakeFsEntry>,
227    next_inode: u64,
228}
229
230#[cfg(any(test, feature = "test-support"))]
231impl FakeFsState {
232    fn validate_path(&self, path: &Path) -> Result<()> {
233        if path.is_absolute()
234            && path
235                .parent()
236                .and_then(|path| self.entries.get(path))
237                .map_or(false, |e| e.metadata.is_dir)
238        {
239            Ok(())
240        } else {
241            Err(anyhow!("invalid path {:?}", path))
242        }
243    }
244}
245
246#[cfg(any(test, feature = "test-support"))]
247pub struct FakeFs {
248    // Use an unfair lock to ensure tests are deterministic.
249    state: futures::lock::Mutex<FakeFsState>,
250    executor: std::sync::Weak<gpui::executor::Background>,
251    events: (
252        async_broadcast::Sender<Vec<fsevent::Event>>,
253        async_broadcast::Receiver<Vec<fsevent::Event>>,
254    ),
255}
256
257#[cfg(any(test, feature = "test-support"))]
258impl FakeFs {
259    pub fn new(executor: std::sync::Arc<gpui::executor::Background>) -> std::sync::Arc<Self> {
260        let mut entries = std::collections::BTreeMap::new();
261        entries.insert(
262            Path::new("/").to_path_buf(),
263            FakeFsEntry {
264                metadata: Metadata {
265                    inode: 0,
266                    mtime: SystemTime::now(),
267                    is_dir: true,
268                    is_symlink: false,
269                },
270                content: None,
271            },
272        );
273        std::sync::Arc::new(Self {
274            executor: std::sync::Arc::downgrade(&executor),
275            state: futures::lock::Mutex::new(FakeFsState {
276                entries,
277                next_inode: 1,
278            }),
279            events: async_broadcast::broadcast(16),
280        })
281    }
282
283    pub async fn insert_dir(&self, path: impl AsRef<Path>) {
284        let mut state = self.state.lock().await;
285        let path = path.as_ref();
286        state.validate_path(path).unwrap();
287
288        let inode = state.next_inode;
289        state.next_inode += 1;
290        state.entries.insert(
291            path.to_path_buf(),
292            FakeFsEntry {
293                metadata: Metadata {
294                    inode,
295                    mtime: SystemTime::now(),
296                    is_dir: true,
297                    is_symlink: false,
298                },
299                content: None,
300            },
301        );
302
303        drop(state);
304        self.emit_event(&[path]).await;
305    }
306
307    pub async fn insert_file(&self, path: impl AsRef<Path>, content: String) {
308        let mut state = self.state.lock().await;
309        let path = path.as_ref();
310        state.validate_path(path).unwrap();
311
312        let inode = state.next_inode;
313        state.next_inode += 1;
314        state.entries.insert(
315            path.to_path_buf(),
316            FakeFsEntry {
317                metadata: Metadata {
318                    inode,
319                    mtime: SystemTime::now(),
320                    is_dir: false,
321                    is_symlink: false,
322                },
323                content: Some(content),
324            },
325        );
326
327        drop(state);
328        self.emit_event(&[path]).await;
329    }
330
331    #[must_use]
332    pub fn insert_tree<'a>(
333        &'a self,
334        path: impl 'a + AsRef<Path> + Send,
335        tree: serde_json::Value,
336    ) -> futures::future::BoxFuture<'a, ()> {
337        use futures::FutureExt as _;
338        use serde_json::Value::*;
339
340        async move {
341            let path = path.as_ref();
342
343            match tree {
344                Object(map) => {
345                    self.insert_dir(path).await;
346                    for (name, contents) in map {
347                        let mut path = PathBuf::from(path);
348                        path.push(name);
349                        self.insert_tree(&path, contents).await;
350                    }
351                }
352                Null => {
353                    self.insert_dir(&path).await;
354                }
355                String(contents) => {
356                    self.insert_file(&path, contents).await;
357                }
358                _ => {
359                    panic!("JSON object must contain only objects, strings, or null");
360                }
361            }
362        }
363        .boxed()
364    }
365
366    async fn simulate_random_delay(&self) {
367        self.executor
368            .upgrade()
369            .expect("excecutor has been dropped")
370            .simulate_random_delay()
371            .await;
372    }
373
374    async fn emit_event<I, T>(&self, paths: I)
375    where
376        I: IntoIterator<Item = T>,
377        T: Into<PathBuf>,
378    {
379        let events = paths
380            .into_iter()
381            .map(|path| fsevent::Event {
382                event_id: 0,
383                flags: fsevent::StreamFlags::empty(),
384                path: path.into(),
385            })
386            .collect::<Vec<_>>();
387
388        let _ = self.events.0.broadcast(events).await;
389    }
390}
391
392#[cfg(any(test, feature = "test-support"))]
393#[async_trait::async_trait]
394impl Fs for FakeFs {
395    async fn create_dir(&self, path: &Path) -> Result<()> {
396        self.simulate_random_delay().await;
397        let state = &mut *self.state.lock().await;
398        let path = normalize_path(path);
399        let mut ancestor_path = PathBuf::new();
400        let mut created_dir_paths = Vec::new();
401        for component in path.components() {
402            ancestor_path.push(component);
403            let entry = state
404                .entries
405                .entry(ancestor_path.clone())
406                .or_insert_with(|| {
407                    let inode = state.next_inode;
408                    state.next_inode += 1;
409                    created_dir_paths.push(ancestor_path.clone());
410                    FakeFsEntry {
411                        metadata: Metadata {
412                            inode,
413                            mtime: SystemTime::now(),
414                            is_dir: true,
415                            is_symlink: false,
416                        },
417                        content: None,
418                    }
419                });
420            if !entry.metadata.is_dir {
421                return Err(anyhow!(
422                    "cannot create directory because {:?} is a file",
423                    ancestor_path
424                ));
425            }
426        }
427        drop(state);
428        self.emit_event(&created_dir_paths).await;
429
430        Ok(())
431    }
432
433    async fn create_file(&self, path: &Path, options: CreateOptions) -> Result<()> {
434        self.simulate_random_delay().await;
435        let mut state = self.state.lock().await;
436        let path = normalize_path(path);
437        state.validate_path(&path)?;
438        if let Some(entry) = state.entries.get_mut(&path) {
439            if entry.metadata.is_dir || entry.metadata.is_symlink {
440                return Err(anyhow!(
441                    "cannot create file because {:?} is a dir or a symlink",
442                    path
443                ));
444            }
445
446            if options.overwrite {
447                entry.metadata.mtime = SystemTime::now();
448                entry.content = Some(Default::default());
449            } else if !options.ignore_if_exists {
450                return Err(anyhow!(
451                    "cannot create file because {:?} already exists",
452                    &path
453                ));
454            }
455        } else {
456            let inode = state.next_inode;
457            state.next_inode += 1;
458            let entry = FakeFsEntry {
459                metadata: Metadata {
460                    inode,
461                    mtime: SystemTime::now(),
462                    is_dir: false,
463                    is_symlink: false,
464                },
465                content: Some(Default::default()),
466            };
467            state.entries.insert(path.to_path_buf(), entry);
468        }
469        drop(state);
470        self.emit_event(&[path]).await;
471
472        Ok(())
473    }
474
475    async fn rename(&self, source: &Path, target: &Path, options: RenameOptions) -> Result<()> {
476        let source = normalize_path(source);
477        let target = normalize_path(target);
478
479        let mut state = self.state.lock().await;
480        state.validate_path(&source)?;
481        state.validate_path(&target)?;
482
483        if !options.overwrite && state.entries.contains_key(&target) {
484            if options.ignore_if_exists {
485                return Ok(());
486            } else {
487                return Err(anyhow!("{target:?} already exists"));
488            }
489        }
490
491        let mut removed = Vec::new();
492        state.entries.retain(|path, entry| {
493            if let Ok(relative_path) = path.strip_prefix(&source) {
494                removed.push((relative_path.to_path_buf(), entry.clone()));
495                false
496            } else {
497                true
498            }
499        });
500
501        for (relative_path, entry) in removed {
502            let new_path = target.join(relative_path);
503            state.entries.insert(new_path, entry);
504        }
505
506        drop(state);
507        self.emit_event(&[source, target]).await;
508        Ok(())
509    }
510
511    async fn remove_dir(&self, path: &Path, options: RemoveOptions) -> Result<()> {
512        let path = normalize_path(path);
513        let mut state = self.state.lock().await;
514        state.validate_path(&path)?;
515        if let Some(entry) = state.entries.get(&path) {
516            if !entry.metadata.is_dir {
517                return Err(anyhow!("cannot remove {path:?} because it is not a dir"));
518            }
519
520            if !options.recursive {
521                let descendants = state
522                    .entries
523                    .keys()
524                    .filter(|path| path.starts_with(path))
525                    .count();
526                if descendants > 1 {
527                    return Err(anyhow!("{path:?} is not empty"));
528                }
529            }
530
531            state.entries.retain(|path, _| !path.starts_with(path));
532            drop(state);
533            self.emit_event(&[path]).await;
534        } else if !options.ignore_if_not_exists {
535            return Err(anyhow!("{path:?} does not exist"));
536        }
537
538        Ok(())
539    }
540
541    async fn remove_file(&self, path: &Path, options: RemoveOptions) -> Result<()> {
542        let path = normalize_path(path);
543        let mut state = self.state.lock().await;
544        state.validate_path(&path)?;
545        if let Some(entry) = state.entries.get(&path) {
546            if entry.metadata.is_dir {
547                return Err(anyhow!("cannot remove {path:?} because it is not a file"));
548            }
549
550            state.entries.remove(&path);
551            drop(state);
552            self.emit_event(&[path]).await;
553        } else if !options.ignore_if_not_exists {
554            return Err(anyhow!("{path:?} does not exist"));
555        }
556        Ok(())
557    }
558
559    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
560        let text = self.load(path).await?;
561        Ok(Box::new(io::Cursor::new(text)))
562    }
563
564    async fn load(&self, path: &Path) -> Result<String> {
565        let path = normalize_path(path);
566        self.simulate_random_delay().await;
567        let state = self.state.lock().await;
568        let text = state
569            .entries
570            .get(&path)
571            .and_then(|e| e.content.as_ref())
572            .ok_or_else(|| anyhow!("file {:?} does not exist", path))?;
573        Ok(text.clone())
574    }
575
576    async fn save(&self, path: &Path, text: &Rope) -> Result<()> {
577        self.simulate_random_delay().await;
578        let mut state = self.state.lock().await;
579        let path = normalize_path(path);
580        state.validate_path(&path)?;
581        if let Some(entry) = state.entries.get_mut(&path) {
582            if entry.metadata.is_dir {
583                Err(anyhow!("cannot overwrite a directory with a file"))
584            } else {
585                entry.content = Some(text.chunks().collect());
586                entry.metadata.mtime = SystemTime::now();
587                drop(state);
588                self.emit_event(&[path]).await;
589                Ok(())
590            }
591        } else {
592            let inode = state.next_inode;
593            state.next_inode += 1;
594            let entry = FakeFsEntry {
595                metadata: Metadata {
596                    inode,
597                    mtime: SystemTime::now(),
598                    is_dir: false,
599                    is_symlink: false,
600                },
601                content: Some(text.chunks().collect()),
602            };
603            state.entries.insert(path.to_path_buf(), entry);
604            drop(state);
605            self.emit_event(&[path]).await;
606            Ok(())
607        }
608    }
609
610    async fn canonicalize(&self, path: &Path) -> Result<PathBuf> {
611        self.simulate_random_delay().await;
612        Ok(normalize_path(path))
613    }
614
615    async fn is_file(&self, path: &Path) -> bool {
616        let path = normalize_path(path);
617        self.simulate_random_delay().await;
618        let state = self.state.lock().await;
619        state
620            .entries
621            .get(&path)
622            .map_or(false, |entry| !entry.metadata.is_dir)
623    }
624
625    async fn metadata(&self, path: &Path) -> Result<Option<Metadata>> {
626        self.simulate_random_delay().await;
627        let state = self.state.lock().await;
628        let path = normalize_path(path);
629        Ok(state.entries.get(&path).map(|entry| entry.metadata.clone()))
630    }
631
632    async fn read_dir(
633        &self,
634        abs_path: &Path,
635    ) -> Result<Pin<Box<dyn Send + Stream<Item = Result<PathBuf>>>>> {
636        use futures::{future, stream};
637        self.simulate_random_delay().await;
638        let state = self.state.lock().await;
639        let abs_path = normalize_path(abs_path);
640        Ok(Box::pin(stream::iter(state.entries.clone()).filter_map(
641            move |(child_path, _)| {
642                future::ready(if child_path.parent() == Some(&abs_path) {
643                    Some(Ok(child_path))
644                } else {
645                    None
646                })
647            },
648        )))
649    }
650
651    async fn watch(
652        &self,
653        path: &Path,
654        _: Duration,
655    ) -> Pin<Box<dyn Send + Stream<Item = Vec<fsevent::Event>>>> {
656        self.simulate_random_delay().await;
657        let rx = self.events.1.clone();
658        let path = path.to_path_buf();
659        Box::pin(futures::StreamExt::filter(rx, move |events| {
660            let result = events.iter().any(|event| event.path.starts_with(&path));
661            async move { result }
662        }))
663    }
664
665    fn is_fake(&self) -> bool {
666        true
667    }
668
669    #[cfg(any(test, feature = "test-support"))]
670    fn as_fake(&self) -> &FakeFs {
671        self
672    }
673}
674
675pub fn normalize_path(path: &Path) -> PathBuf {
676    let mut components = path.components().peekable();
677    let mut ret = if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
678        components.next();
679        PathBuf::from(c.as_os_str())
680    } else {
681        PathBuf::new()
682    };
683
684    for component in components {
685        match component {
686            Component::Prefix(..) => unreachable!(),
687            Component::RootDir => {
688                ret.push(component.as_os_str());
689            }
690            Component::CurDir => {}
691            Component::ParentDir => {
692                ret.pop();
693            }
694            Component::Normal(c) => {
695                ret.push(c);
696            }
697        }
698    }
699    ret
700}