wasmtime_wasi/p3/filesystem/
host.rs

1use crate::filesystem::{Descriptor, Dir, File, WasiFilesystem, WasiFilesystemCtxView};
2use crate::p3::bindings::clocks::system_clock;
3use crate::p3::bindings::filesystem::types::{
4    self, Advice, DescriptorFlags, DescriptorStat, DescriptorType, DirectoryEntry, ErrorCode,
5    Filesize, MetadataHashValue, NewTimestamp, OpenFlags, PathFlags,
6};
7use crate::p3::filesystem::{FilesystemError, FilesystemResult, preopens};
8use crate::p3::{DEFAULT_BUFFER_CAPACITY, FallibleIteratorProducer};
9use crate::{DirPerms, FilePerms};
10use bytes::BytesMut;
11use core::pin::Pin;
12use core::task::{Context, Poll, ready};
13use core::{iter, mem};
14use std::io::{self, Cursor};
15use std::sync::Arc;
16use system_interface::fs::FileIoExt as _;
17use tokio::sync::{mpsc, oneshot};
18use tokio::task::{JoinHandle, spawn_blocking};
19use wasmtime::StoreContextMut;
20use wasmtime::component::{
21    Access, Accessor, Destination, FutureReader, Resource, ResourceTable, Source, StreamConsumer,
22    StreamProducer, StreamReader, StreamResult,
23};
24use wasmtime::error::Context as _;
25
26fn get_descriptor<'a>(
27    table: &'a ResourceTable,
28    fd: &'a Resource<Descriptor>,
29) -> FilesystemResult<&'a Descriptor> {
30    table
31        .get(fd)
32        .context("failed to get descriptor resource from table")
33        .map_err(FilesystemError::trap)
34}
35
36fn get_file<'a>(
37    table: &'a ResourceTable,
38    fd: &'a Resource<Descriptor>,
39) -> FilesystemResult<&'a File> {
40    let file = get_descriptor(table, fd).map(Descriptor::file)??;
41    Ok(file)
42}
43
44fn get_dir<'a>(
45    table: &'a ResourceTable,
46    fd: &'a Resource<Descriptor>,
47) -> FilesystemResult<&'a Dir> {
48    let dir = get_descriptor(table, fd).map(Descriptor::dir)??;
49    Ok(dir)
50}
51
52trait AccessorExt {
53    fn get_descriptor(&self, fd: &Resource<Descriptor>) -> FilesystemResult<Descriptor>;
54    fn get_file(&self, fd: &Resource<Descriptor>) -> FilesystemResult<File>;
55    fn get_dir(&self, fd: &Resource<Descriptor>) -> FilesystemResult<Dir>;
56    fn get_dir_pair(
57        &self,
58        a: &Resource<Descriptor>,
59        b: &Resource<Descriptor>,
60    ) -> FilesystemResult<(Dir, Dir)>;
61}
62
63impl<T> AccessorExt for Accessor<T, WasiFilesystem> {
64    fn get_descriptor(&self, fd: &Resource<Descriptor>) -> FilesystemResult<Descriptor> {
65        self.with(|mut store| {
66            let fd = get_descriptor(store.get().table, fd)?;
67            Ok(fd.clone())
68        })
69    }
70
71    fn get_file(&self, fd: &Resource<Descriptor>) -> FilesystemResult<File> {
72        self.with(|mut store| {
73            let file = get_file(store.get().table, fd)?;
74            Ok(file.clone())
75        })
76    }
77
78    fn get_dir(&self, fd: &Resource<Descriptor>) -> FilesystemResult<Dir> {
79        self.with(|mut store| {
80            let dir = get_dir(store.get().table, fd)?;
81            Ok(dir.clone())
82        })
83    }
84
85    fn get_dir_pair(
86        &self,
87        a: &Resource<Descriptor>,
88        b: &Resource<Descriptor>,
89    ) -> FilesystemResult<(Dir, Dir)> {
90        self.with(|mut store| {
91            let table = store.get().table;
92            let a = get_dir(table, a)?;
93            let b = get_dir(table, b)?;
94            Ok((a.clone(), b.clone()))
95        })
96    }
97}
98
99fn systemtime_from(t: system_clock::Instant) -> Result<std::time::SystemTime, ErrorCode> {
100    if let Ok(seconds) = t.seconds.try_into() {
101        std::time::SystemTime::UNIX_EPOCH
102            .checked_add(core::time::Duration::new(seconds, t.nanoseconds))
103            .ok_or(ErrorCode::Overflow)
104    } else {
105        std::time::SystemTime::UNIX_EPOCH
106            .checked_sub(core::time::Duration::new(
107                t.seconds.unsigned_abs(),
108                t.nanoseconds,
109            ))
110            .ok_or(ErrorCode::Overflow)
111    }
112}
113
114fn systemtimespec_from(t: NewTimestamp) -> Result<Option<fs_set_times::SystemTimeSpec>, ErrorCode> {
115    use fs_set_times::SystemTimeSpec;
116    match t {
117        NewTimestamp::NoChange => Ok(None),
118        NewTimestamp::Now => Ok(Some(SystemTimeSpec::SymbolicNow)),
119        NewTimestamp::Timestamp(st) => {
120            let st = systemtime_from(st)?;
121            Ok(Some(SystemTimeSpec::Absolute(st)))
122        }
123    }
124}
125
126struct ReadStreamProducer {
127    file: File,
128    offset: u64,
129    result: Option<oneshot::Sender<Result<(), ErrorCode>>>,
130    task: Option<JoinHandle<std::io::Result<BytesMut>>>,
131}
132
133impl Drop for ReadStreamProducer {
134    fn drop(&mut self) {
135        self.close(Ok(()))
136    }
137}
138
139impl ReadStreamProducer {
140    fn close(&mut self, res: Result<(), ErrorCode>) {
141        if let Some(tx) = self.result.take() {
142            _ = tx.send(res);
143        }
144    }
145
146    /// Update the internal `offset` field after reading `amt` bytes from the file.
147    fn complete_read(&mut self, amt: usize) -> StreamResult {
148        let Ok(amt) = amt.try_into() else {
149            self.close(Err(ErrorCode::Overflow));
150            return StreamResult::Dropped;
151        };
152        let Some(amt) = self.offset.checked_add(amt) else {
153            self.close(Err(ErrorCode::Overflow));
154            return StreamResult::Dropped;
155        };
156        self.offset = amt;
157        StreamResult::Completed
158    }
159}
160
161impl<D> StreamProducer<D> for ReadStreamProducer {
162    type Item = u8;
163    type Buffer = Cursor<BytesMut>;
164
165    fn poll_produce<'a>(
166        mut self: Pin<&mut Self>,
167        cx: &mut Context<'_>,
168        store: StoreContextMut<'a, D>,
169        mut dst: Destination<'a, Self::Item, Self::Buffer>,
170        // Intentionally ignore this as in blocking mode everything is always
171        // ready and otherwise spawned blocking work can't be cancelled.
172        _finish: bool,
173    ) -> Poll<wasmtime::Result<StreamResult>> {
174        if let Some(file) = self.file.as_blocking_file() {
175            // Once a blocking file, always a blocking file, so assert as such.
176            assert!(self.task.is_none());
177            let mut dst = dst.as_direct(store, DEFAULT_BUFFER_CAPACITY);
178            let buf = dst.remaining();
179            if buf.is_empty() {
180                return Poll::Ready(Ok(StreamResult::Completed));
181            }
182            return match file.read_at(buf, self.offset) {
183                Ok(0) => {
184                    self.close(Ok(()));
185                    Poll::Ready(Ok(StreamResult::Dropped))
186                }
187                Ok(n) => {
188                    dst.mark_written(n);
189                    Poll::Ready(Ok(self.complete_read(n)))
190                }
191                Err(err) => {
192                    self.close(Err(err.into()));
193                    Poll::Ready(Ok(StreamResult::Dropped))
194                }
195            };
196        }
197
198        // Lazily spawn a read task if one hasn't already been spawned yet.
199        let me = &mut *self;
200        let task = me.task.get_or_insert_with(|| {
201            let mut buf = dst.take_buffer().into_inner();
202            buf.resize(DEFAULT_BUFFER_CAPACITY, 0);
203            let file = Arc::clone(me.file.as_file());
204            let offset = me.offset;
205            spawn_blocking(move || {
206                file.read_at(&mut buf, offset).map(|n| {
207                    buf.truncate(n);
208                    buf
209                })
210            })
211        });
212
213        // Await the completion of the read task. Note that this is not a
214        // cancellable await point because we can't cancel the other task, so
215        // the `finish` parameter is ignored.
216        let res = ready!(Pin::new(task).poll(cx)).expect("I/O task should not panic");
217        self.task = None;
218        match res {
219            Ok(buf) if buf.is_empty() => {
220                self.close(Ok(()));
221                Poll::Ready(Ok(StreamResult::Dropped))
222            }
223            Ok(buf) => {
224                let n = buf.len();
225                dst.set_buffer(Cursor::new(buf));
226                Poll::Ready(Ok(self.complete_read(n)))
227            }
228            Err(err) => {
229                self.close(Err(err.into()));
230                Poll::Ready(Ok(StreamResult::Dropped))
231            }
232        }
233    }
234}
235
236fn map_dir_entry(
237    entry: std::io::Result<cap_std::fs::DirEntry>,
238) -> Result<Option<DirectoryEntry>, ErrorCode> {
239    match entry {
240        Ok(entry) => {
241            let meta = entry.metadata()?;
242            let Ok(name) = entry.file_name().into_string() else {
243                return Err(ErrorCode::IllegalByteSequence);
244            };
245            Ok(Some(DirectoryEntry {
246                type_: meta.file_type().into(),
247                name,
248            }))
249        }
250        Err(err) => {
251            // On windows, filter out files like `C:\DumpStack.log.tmp` which we
252            // can't get full metadata for.
253            #[cfg(windows)]
254            {
255                use windows_sys::Win32::Foundation::{
256                    ERROR_ACCESS_DENIED, ERROR_SHARING_VIOLATION,
257                };
258                if err.raw_os_error() == Some(ERROR_SHARING_VIOLATION as i32)
259                    || err.raw_os_error() == Some(ERROR_ACCESS_DENIED as i32)
260                {
261                    return Ok(None);
262                }
263            }
264            Err(err.into())
265        }
266    }
267}
268
269struct ReadDirStream {
270    rx: mpsc::Receiver<DirectoryEntry>,
271    task: JoinHandle<Result<(), ErrorCode>>,
272    result: Option<oneshot::Sender<Result<(), ErrorCode>>>,
273}
274
275impl ReadDirStream {
276    fn new(
277        dir: Arc<cap_std::fs::Dir>,
278        result: oneshot::Sender<Result<(), ErrorCode>>,
279    ) -> ReadDirStream {
280        let (tx, rx) = mpsc::channel(1);
281        ReadDirStream {
282            task: spawn_blocking(move || {
283                let entries = dir.entries()?;
284                for entry in entries {
285                    if let Some(entry) = map_dir_entry(entry)? {
286                        if let Err(_) = tx.blocking_send(entry) {
287                            break;
288                        }
289                    }
290                }
291                Ok(())
292            }),
293            rx,
294            result: Some(result),
295        }
296    }
297
298    fn close(&mut self, res: Result<(), ErrorCode>) {
299        self.rx.close();
300        self.task.abort();
301        let _ = self.result.take().unwrap().send(res);
302    }
303}
304
305impl<D> StreamProducer<D> for ReadDirStream {
306    type Item = DirectoryEntry;
307    type Buffer = Option<DirectoryEntry>;
308
309    fn poll_produce<'a>(
310        mut self: Pin<&mut Self>,
311        cx: &mut Context<'_>,
312        mut store: StoreContextMut<'a, D>,
313        mut dst: Destination<'a, Self::Item, Self::Buffer>,
314        finish: bool,
315    ) -> Poll<wasmtime::Result<StreamResult>> {
316        // If this is a 0-length read then `mpsc::Receiver` does not expose an
317        // API to wait for an item to be available without taking it out of the
318        // channel. In lieu of that just say that we're complete and ready for a
319        // read.
320        if dst.remaining(&mut store) == Some(0) {
321            return Poll::Ready(Ok(StreamResult::Completed));
322        }
323
324        match self.rx.poll_recv(cx) {
325            // If an item is on the channel then send that along and say that
326            // the read is now complete with one item being yielded.
327            Poll::Ready(Some(item)) => {
328                dst.set_buffer(Some(item));
329                Poll::Ready(Ok(StreamResult::Completed))
330            }
331
332            // If there's nothing left on the channel then that means that an
333            // error occurred or the iterator is done. In both cases an
334            // un-cancellable wait for the spawned task is entered and we await
335            // its completion. Upon completion there our own stream is closed
336            // with the result (sending an error code on our oneshot) and then
337            // the stream is reported as dropped.
338            Poll::Ready(None) => {
339                let result = ready!(Pin::new(&mut self.task).poll(cx))
340                    .expect("spawned task should not panic");
341                self.close(result);
342                Poll::Ready(Ok(StreamResult::Dropped))
343            }
344
345            // If an item isn't ready yet then cancel this outstanding request
346            // if `finish` is set, otherwise propagate the `Pending` status.
347            Poll::Pending if finish => Poll::Ready(Ok(StreamResult::Cancelled)),
348            Poll::Pending => Poll::Pending,
349        }
350    }
351}
352
353impl Drop for ReadDirStream {
354    fn drop(&mut self) {
355        if self.result.is_some() {
356            self.close(Ok(()));
357        }
358    }
359}
360
361struct WriteStreamConsumer {
362    file: File,
363    location: WriteLocation,
364    result: Option<oneshot::Sender<Result<(), ErrorCode>>>,
365    buffer: BytesMut,
366    task: Option<JoinHandle<std::io::Result<(BytesMut, usize)>>>,
367}
368
369#[derive(Copy, Clone)]
370enum WriteLocation {
371    End,
372    Offset(u64),
373}
374
375impl WriteStreamConsumer {
376    fn new_at(file: File, offset: u64, result: oneshot::Sender<Result<(), ErrorCode>>) -> Self {
377        Self {
378            file,
379            location: WriteLocation::Offset(offset),
380            result: Some(result),
381            buffer: BytesMut::default(),
382            task: None,
383        }
384    }
385
386    fn new_append(file: File, result: oneshot::Sender<Result<(), ErrorCode>>) -> Self {
387        Self {
388            file,
389            location: WriteLocation::End,
390            result: Some(result),
391            buffer: BytesMut::default(),
392            task: None,
393        }
394    }
395
396    fn close(&mut self, res: Result<(), ErrorCode>) {
397        _ = self.result.take().unwrap().send(res);
398    }
399
400    /// Update the internal `offset` field after writing `amt` bytes from the file.
401    fn complete_write(&mut self, amt: usize) -> StreamResult {
402        match &mut self.location {
403            WriteLocation::End => StreamResult::Completed,
404            WriteLocation::Offset(offset) => {
405                let Ok(amt) = amt.try_into() else {
406                    self.close(Err(ErrorCode::Overflow));
407                    return StreamResult::Dropped;
408                };
409                let Some(amt) = offset.checked_add(amt) else {
410                    self.close(Err(ErrorCode::Overflow));
411                    return StreamResult::Dropped;
412                };
413                *offset = amt;
414                StreamResult::Completed
415            }
416        }
417    }
418}
419
420impl WriteLocation {
421    fn write(&self, file: &cap_std::fs::File, bytes: &[u8]) -> io::Result<usize> {
422        match *self {
423            WriteLocation::End => file.append(bytes),
424            WriteLocation::Offset(at) => file.write_at(bytes, at),
425        }
426    }
427}
428
429impl<D> StreamConsumer<D> for WriteStreamConsumer {
430    type Item = u8;
431
432    fn poll_consume(
433        mut self: Pin<&mut Self>,
434        cx: &mut Context<'_>,
435        store: StoreContextMut<D>,
436        src: Source<Self::Item>,
437        // Intentionally ignore this as in blocking mode everything is always
438        // ready and otherwise spawned blocking work can't be cancelled.
439        _finish: bool,
440    ) -> Poll<wasmtime::Result<StreamResult>> {
441        let mut src = src.as_direct(store);
442        if let Some(file) = self.file.as_blocking_file() {
443            // Once a blocking file, always a blocking file, so assert as such.
444            assert!(self.task.is_none());
445            return match self.location.write(file, src.remaining()) {
446                Ok(n) => {
447                    src.mark_read(n);
448                    Poll::Ready(Ok(self.complete_write(n)))
449                }
450                Err(err) => {
451                    self.close(Err(err.into()));
452                    Poll::Ready(Ok(StreamResult::Dropped))
453                }
454            };
455        }
456        let me = &mut *self;
457        let task = me.task.get_or_insert_with(|| {
458            debug_assert!(me.buffer.is_empty());
459            me.buffer.extend_from_slice(src.remaining());
460            let buf = mem::take(&mut me.buffer);
461            let file = Arc::clone(me.file.as_file());
462            let location = me.location;
463            spawn_blocking(move || location.write(&file, &buf).map(|n| (buf, n)))
464        });
465        let res = ready!(Pin::new(task).poll(cx)).expect("I/O task should not panic");
466        self.task = None;
467        match res {
468            Ok((buf, n)) => {
469                src.mark_read(n);
470                self.buffer = buf;
471                self.buffer.clear();
472                Poll::Ready(Ok(self.complete_write(n)))
473            }
474            Err(err) => {
475                self.close(Err(err.into()));
476                Poll::Ready(Ok(StreamResult::Dropped))
477            }
478        }
479    }
480}
481
482impl Drop for WriteStreamConsumer {
483    fn drop(&mut self) {
484        if self.result.is_some() {
485            self.close(Ok(()))
486        }
487    }
488}
489
490impl types::Host for WasiFilesystemCtxView<'_> {
491    fn convert_error_code(&mut self, error: FilesystemError) -> wasmtime::Result<ErrorCode> {
492        error.downcast()
493    }
494}
495
496impl types::HostDescriptorWithStore for WasiFilesystem {
497    fn read_via_stream<U>(
498        mut store: Access<U, Self>,
499        fd: Resource<Descriptor>,
500        offset: Filesize,
501    ) -> wasmtime::Result<(StreamReader<u8>, FutureReader<Result<(), ErrorCode>>)> {
502        let file = get_file(store.get().table, &fd)?;
503        if !file.perms.contains(FilePerms::READ) {
504            return Ok((
505                StreamReader::new(&mut store, iter::empty()),
506                FutureReader::new(&mut store, async {
507                    wasmtime::error::Ok(Err(ErrorCode::NotPermitted))
508                }),
509            ));
510        }
511
512        let file = file.clone();
513        let (result_tx, result_rx) = oneshot::channel();
514        Ok((
515            StreamReader::new(
516                &mut store,
517                ReadStreamProducer {
518                    file,
519                    offset,
520                    result: Some(result_tx),
521                    task: None,
522                },
523            ),
524            FutureReader::new(&mut store, result_rx),
525        ))
526    }
527
528    async fn write_via_stream<U>(
529        store: &Accessor<U, Self>,
530        fd: Resource<Descriptor>,
531        data: StreamReader<u8>,
532        offset: Filesize,
533    ) -> FilesystemResult<()> {
534        let (result_tx, result_rx) = oneshot::channel();
535        store.with(|mut store| {
536            let file = get_file(store.get().table, &fd)?;
537            if !file.perms.contains(FilePerms::WRITE) {
538                return Err(ErrorCode::NotPermitted.into());
539            }
540            let file = file.clone();
541            data.pipe(store, WriteStreamConsumer::new_at(file, offset, result_tx));
542            FilesystemResult::Ok(())
543        })?;
544        result_rx
545            .await
546            .context("oneshot sender dropped")
547            .map_err(FilesystemError::trap)??;
548        Ok(())
549    }
550
551    async fn append_via_stream<U>(
552        store: &Accessor<U, Self>,
553        fd: Resource<Descriptor>,
554        data: StreamReader<u8>,
555    ) -> FilesystemResult<()> {
556        let (result_tx, result_rx) = oneshot::channel();
557        store.with(|mut store| {
558            let file = get_file(store.get().table, &fd)?;
559            if !file.perms.contains(FilePerms::WRITE) {
560                return Err(ErrorCode::NotPermitted.into());
561            }
562            let file = file.clone();
563            data.pipe(store, WriteStreamConsumer::new_append(file, result_tx));
564            FilesystemResult::Ok(())
565        })?;
566        result_rx
567            .await
568            .context("oneshot sender dropped")
569            .map_err(FilesystemError::trap)??;
570        Ok(())
571    }
572
573    async fn advise<U>(
574        store: &Accessor<U, Self>,
575        fd: Resource<Descriptor>,
576        offset: Filesize,
577        length: Filesize,
578        advice: Advice,
579    ) -> FilesystemResult<()> {
580        let file = store.get_file(&fd)?;
581        file.advise(offset, length, advice.into()).await?;
582        Ok(())
583    }
584
585    async fn sync_data<U>(
586        store: &Accessor<U, Self>,
587        fd: Resource<Descriptor>,
588    ) -> FilesystemResult<()> {
589        let fd = store.get_descriptor(&fd)?;
590        fd.sync_data().await?;
591        Ok(())
592    }
593
594    async fn get_flags<U>(
595        store: &Accessor<U, Self>,
596        fd: Resource<Descriptor>,
597    ) -> FilesystemResult<DescriptorFlags> {
598        let fd = store.get_descriptor(&fd)?;
599        let flags = fd.get_flags().await?;
600        Ok(flags.into())
601    }
602
603    async fn get_type<U>(
604        store: &Accessor<U, Self>,
605        fd: Resource<Descriptor>,
606    ) -> FilesystemResult<DescriptorType> {
607        let fd = store.get_descriptor(&fd)?;
608        let ty = fd.get_type().await?;
609        Ok(ty.into())
610    }
611
612    async fn set_size<U>(
613        store: &Accessor<U, Self>,
614        fd: Resource<Descriptor>,
615        size: Filesize,
616    ) -> FilesystemResult<()> {
617        let file = store.get_file(&fd)?;
618        file.set_size(size).await?;
619        Ok(())
620    }
621
622    async fn set_times<U>(
623        store: &Accessor<U, Self>,
624        fd: Resource<Descriptor>,
625        data_access_timestamp: NewTimestamp,
626        data_modification_timestamp: NewTimestamp,
627    ) -> FilesystemResult<()> {
628        let fd = store.get_descriptor(&fd)?;
629        let atim = systemtimespec_from(data_access_timestamp)?;
630        let mtim = systemtimespec_from(data_modification_timestamp)?;
631        fd.set_times(atim, mtim).await?;
632        Ok(())
633    }
634
635    async fn read_directory<U>(
636        store: &Accessor<U, Self>,
637        fd: Resource<Descriptor>,
638    ) -> wasmtime::Result<(
639        StreamReader<DirectoryEntry>,
640        FutureReader<Result<(), ErrorCode>>,
641    )> {
642        store.with(|mut store| {
643            let dir = get_dir(store.get().table, &fd)?;
644            if !dir.perms.contains(DirPerms::READ) {
645                return Ok((
646                    StreamReader::new(&mut store, iter::empty()),
647                    FutureReader::new(&mut store, async {
648                        wasmtime::error::Ok(Err(ErrorCode::NotPermitted))
649                    }),
650                ));
651            }
652            let allow_blocking_current_thread = dir.allow_blocking_current_thread;
653            let dir = Arc::clone(dir.as_dir());
654            let (result_tx, result_rx) = oneshot::channel();
655            let stream = if allow_blocking_current_thread {
656                match dir.entries() {
657                    Ok(readdir) => StreamReader::new(
658                        &mut store,
659                        FallibleIteratorProducer::new(
660                            readdir.filter_map(|e| map_dir_entry(e).transpose()),
661                            result_tx,
662                        ),
663                    ),
664                    Err(e) => {
665                        result_tx.send(Err(e.into())).unwrap();
666                        StreamReader::new(&mut store, iter::empty())
667                    }
668                }
669            } else {
670                StreamReader::new(&mut store, ReadDirStream::new(dir, result_tx))
671            };
672            Ok((stream, FutureReader::new(&mut store, result_rx)))
673        })
674    }
675
676    async fn sync<U>(store: &Accessor<U, Self>, fd: Resource<Descriptor>) -> FilesystemResult<()> {
677        let fd = store.get_descriptor(&fd)?;
678        fd.sync().await?;
679        Ok(())
680    }
681
682    async fn create_directory_at<U>(
683        store: &Accessor<U, Self>,
684        fd: Resource<Descriptor>,
685        path: String,
686    ) -> FilesystemResult<()> {
687        let dir = store.get_dir(&fd)?;
688        dir.create_directory_at(path).await?;
689        Ok(())
690    }
691
692    async fn stat<U>(
693        store: &Accessor<U, Self>,
694        fd: Resource<Descriptor>,
695    ) -> FilesystemResult<DescriptorStat> {
696        let fd = store.get_descriptor(&fd)?;
697        let stat = fd.stat().await?;
698        Ok(stat.into())
699    }
700
701    async fn stat_at<U>(
702        store: &Accessor<U, Self>,
703        fd: Resource<Descriptor>,
704        path_flags: PathFlags,
705        path: String,
706    ) -> FilesystemResult<DescriptorStat> {
707        let dir = store.get_dir(&fd)?;
708        let stat = dir.stat_at(path_flags.into(), path).await?;
709        Ok(stat.into())
710    }
711
712    async fn set_times_at<U>(
713        store: &Accessor<U, Self>,
714        fd: Resource<Descriptor>,
715        path_flags: PathFlags,
716        path: String,
717        data_access_timestamp: NewTimestamp,
718        data_modification_timestamp: NewTimestamp,
719    ) -> FilesystemResult<()> {
720        let dir = store.get_dir(&fd)?;
721        let atim = systemtimespec_from(data_access_timestamp)?;
722        let mtim = systemtimespec_from(data_modification_timestamp)?;
723        dir.set_times_at(path_flags.into(), path, atim, mtim)
724            .await?;
725        Ok(())
726    }
727
728    async fn link_at<U>(
729        store: &Accessor<U, Self>,
730        fd: Resource<Descriptor>,
731        old_path_flags: PathFlags,
732        old_path: String,
733        new_fd: Resource<Descriptor>,
734        new_path: String,
735    ) -> FilesystemResult<()> {
736        let (old_dir, new_dir) = store.get_dir_pair(&fd, &new_fd)?;
737        old_dir
738            .link_at(old_path_flags.into(), old_path, &new_dir, new_path)
739            .await?;
740        Ok(())
741    }
742
743    async fn open_at<U>(
744        store: &Accessor<U, Self>,
745        fd: Resource<Descriptor>,
746        path_flags: PathFlags,
747        path: String,
748        open_flags: OpenFlags,
749        flags: DescriptorFlags,
750    ) -> FilesystemResult<Resource<Descriptor>> {
751        let (allow_blocking_current_thread, dir) = store.with(|mut store| {
752            let store = store.get();
753            let dir = get_dir(&store.table, &fd)?;
754            FilesystemResult::Ok((store.ctx.allow_blocking_current_thread, dir.clone()))
755        })?;
756        let fd = dir
757            .open_at(
758                path_flags.into(),
759                path,
760                open_flags.into(),
761                flags.into(),
762                allow_blocking_current_thread,
763            )
764            .await?;
765        let fd = store.with(|mut store| store.get().table.push(fd))?;
766        Ok(fd)
767    }
768
769    async fn readlink_at<U>(
770        store: &Accessor<U, Self>,
771        fd: Resource<Descriptor>,
772        path: String,
773    ) -> FilesystemResult<String> {
774        let dir = store.get_dir(&fd)?;
775        let path = dir.readlink_at(path).await?;
776        Ok(path)
777    }
778
779    async fn remove_directory_at<U>(
780        store: &Accessor<U, Self>,
781        fd: Resource<Descriptor>,
782        path: String,
783    ) -> FilesystemResult<()> {
784        let dir = store.get_dir(&fd)?;
785        dir.remove_directory_at(path).await?;
786        Ok(())
787    }
788
789    async fn rename_at<U>(
790        store: &Accessor<U, Self>,
791        fd: Resource<Descriptor>,
792        old_path: String,
793        new_fd: Resource<Descriptor>,
794        new_path: String,
795    ) -> FilesystemResult<()> {
796        let (old_dir, new_dir) = store.get_dir_pair(&fd, &new_fd)?;
797        old_dir.rename_at(old_path, &new_dir, new_path).await?;
798        Ok(())
799    }
800
801    async fn symlink_at<U>(
802        store: &Accessor<U, Self>,
803        fd: Resource<Descriptor>,
804        old_path: String,
805        new_path: String,
806    ) -> FilesystemResult<()> {
807        let dir = store.get_dir(&fd)?;
808        dir.symlink_at(old_path, new_path).await?;
809        Ok(())
810    }
811
812    async fn unlink_file_at<U>(
813        store: &Accessor<U, Self>,
814        fd: Resource<Descriptor>,
815        path: String,
816    ) -> FilesystemResult<()> {
817        let dir = store.get_dir(&fd)?;
818        dir.unlink_file_at(path).await?;
819        Ok(())
820    }
821
822    async fn is_same_object<U>(
823        store: &Accessor<U, Self>,
824        fd: Resource<Descriptor>,
825        other: Resource<Descriptor>,
826    ) -> wasmtime::Result<bool> {
827        let (fd, other) = store.with(|mut store| {
828            let table = store.get().table;
829            let fd = get_descriptor(table, &fd)?.clone();
830            let other = get_descriptor(table, &other)?.clone();
831            wasmtime::error::Ok((fd, other))
832        })?;
833        fd.is_same_object(&other).await
834    }
835
836    async fn metadata_hash<U>(
837        store: &Accessor<U, Self>,
838        fd: Resource<Descriptor>,
839    ) -> FilesystemResult<MetadataHashValue> {
840        let fd = store.get_descriptor(&fd)?;
841        let meta = fd.metadata_hash().await?;
842        Ok(meta.into())
843    }
844
845    async fn metadata_hash_at<U>(
846        store: &Accessor<U, Self>,
847        fd: Resource<Descriptor>,
848        path_flags: PathFlags,
849        path: String,
850    ) -> FilesystemResult<MetadataHashValue> {
851        let dir = store.get_dir(&fd)?;
852        let meta = dir.metadata_hash_at(path_flags.into(), path).await?;
853        Ok(meta.into())
854    }
855}
856
857impl types::HostDescriptor for WasiFilesystemCtxView<'_> {
858    fn drop(&mut self, fd: Resource<Descriptor>) -> wasmtime::Result<()> {
859        self.table
860            .delete(fd)
861            .context("failed to delete descriptor resource from table")?;
862        Ok(())
863    }
864}
865
866impl preopens::Host for WasiFilesystemCtxView<'_> {
867    fn get_directories(&mut self) -> wasmtime::Result<Vec<(Resource<Descriptor>, String)>> {
868        self.get_directories()
869    }
870}
wasmtime_wasi/p3/filesystem/host.rs

wasmtime_wasi/p3/filesystem/
host.rs
