-
Notifications
You must be signed in to change notification settings - Fork 105
/
fs.rs
448 lines (398 loc) · 15.5 KB
/
fs.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
// Copyright 2022 The Native Link Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::borrow::Cow;
use std::ffi::OsStr;
use std::fs::Metadata;
use std::io::IoSlice;
use std::path::{Path, PathBuf};
use std::pin::Pin;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::OnceLock;
use std::task::{Context, Poll};
use std::time::Duration;
use bytes::BytesMut;
use error::{make_err, Code, Error, ResultExt};
use futures::Future;
use tokio::io::{AsyncRead, AsyncReadExt, AsyncSeek, AsyncSeekExt, AsyncWrite, ReadBuf, SeekFrom, Take};
use tokio::sync::{Semaphore, SemaphorePermit};
use tokio::time::timeout;
/// We wrap all tokio::fs items in our own wrapper so we can limit the number of outstanding
/// open files at any given time. This will greatly reduce the chance we'll hit open file limit
/// issues.
pub use tokio::fs::DirEntry;
type StreamPosition = u64;
type BytesRemaining = u64;
#[derive(Debug)]
enum MaybeFileSlot {
Open(Take<FileSlot>),
Closed((StreamPosition, BytesRemaining)),
}
/// A wrapper around a generic FileSlot. This gives us the ability to
/// close a file and then resume it later. Specifically useful for cases
/// piping data from one location to another and one side is slow at
/// reading or writing the data, we can have a timeout, close the file
/// and then reopen it later.
///
/// Note: This wraps both files opened for read and write, so we always
/// need to know how the original file was opened and the location of
/// the file. To simplify the code significantly we always require the
/// file to be a Take<FileSlot>.
#[derive(Debug)]
pub struct ResumeableFileSlot<'a> {
maybe_file_slot: MaybeFileSlot,
path: Cow<'a, OsStr>,
is_write: bool,
}
impl<'a> ResumeableFileSlot<'a> {
pub fn new(file: FileSlot, path: impl Into<Cow<'a, OsStr>>, is_write: bool) -> Self {
Self {
maybe_file_slot: MaybeFileSlot::Open(file.take(u64::MAX)),
path: path.into(),
is_write,
}
}
pub fn new_with_take(file: Take<FileSlot>, path: impl Into<Cow<'a, OsStr>>, is_write: bool) -> Self {
Self {
maybe_file_slot: MaybeFileSlot::Open(file),
path: path.into(),
is_write,
}
}
pub async fn close_file(&mut self) -> Result<(), Error> {
let MaybeFileSlot::Open(file_slot) = &mut self.maybe_file_slot else {
return Ok(());
};
let position = file_slot
.get_mut()
.inner
.stream_position()
.await
.err_tip(|| format!("Failed to get file position {:?}", self.path))?;
self.maybe_file_slot = MaybeFileSlot::Closed((position, file_slot.limit()));
Ok(())
}
#[inline]
pub async fn as_reader(&mut self) -> Result<&mut Take<FileSlot>, Error> {
let (stream_position, bytes_remaining) = match self.maybe_file_slot {
MaybeFileSlot::Open(ref mut file_slot) => return Ok(file_slot),
MaybeFileSlot::Closed(pos) => pos,
};
let permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
let inner = tokio::fs::OpenOptions::new()
.write(self.is_write)
.read(!self.is_write)
.open(&self.path)
.await
.err_tip(|| format!("Could not open after resume {:?}", self.path))?;
let mut file_slot = FileSlot { _permit: permit, inner };
file_slot
.inner
.seek(SeekFrom::Start(stream_position))
.await
.err_tip(|| format!("Failed to seek to position {:?} {:?}", stream_position, self.path))?;
self.maybe_file_slot = MaybeFileSlot::Open(file_slot.take(bytes_remaining));
match &mut self.maybe_file_slot {
MaybeFileSlot::Open(file_slot) => Ok(file_slot),
MaybeFileSlot::Closed(_) => unreachable!(),
}
}
#[inline]
pub async fn as_writer(&mut self) -> Result<&mut FileSlot, Error> {
Ok(self.as_reader().await?.get_mut())
}
/// Utility function to read data from a handler and handles file descriptor
/// timeouts. Chunk size is based on the `buf`'s capacity.
/// Note: If the `handler` changes `buf`s capcity, it is responsible for reserving
/// more before returning.
pub async fn read_buf_cb<'b, T, F, Fut>(
&'b mut self,
(mut buf, mut state): (BytesMut, T),
mut handler: F,
) -> Result<(BytesMut, T), Error>
where
F: (FnMut((BytesMut, T)) -> Fut) + 'b,
Fut: Future<Output = Result<(BytesMut, T), Error>> + 'b,
{
loop {
buf.clear();
self.as_reader()
.await
.err_tip(|| "Could not get reader from file slot in read_buf_cb")?
.read_buf(&mut buf)
.await
.err_tip(|| "Could not read chunk during read_buf_cb")?;
if buf.is_empty() {
return Ok((buf, state));
}
let handler_fut = handler((buf, state));
tokio::pin!(handler_fut);
loop {
match timeout(idle_file_descriptor_timeout(), &mut handler_fut).await {
Ok(Ok(output)) => {
(buf, state) = output;
break;
}
Ok(Err(err)) => return Err(err).err_tip(|| "read_buf_cb's handler returned an error"),
Err(_) => {
self.close_file()
.await
.err_tip(|| "Could not close file due to timeout in read_buf_cb")?;
continue;
}
}
}
}
}
}
#[derive(Debug)]
pub struct FileSlot {
// We hold the permit because once it is dropped it goes back into the queue.
_permit: SemaphorePermit<'static>,
inner: tokio::fs::File,
}
impl AsRef<tokio::fs::File> for FileSlot {
fn as_ref(&self) -> &tokio::fs::File {
&self.inner
}
}
impl AsMut<tokio::fs::File> for FileSlot {
fn as_mut(&mut self) -> &mut tokio::fs::File {
&mut self.inner
}
}
impl AsyncRead for FileSlot {
fn poll_read(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<Result<(), tokio::io::Error>> {
Pin::new(&mut self.inner).poll_read(cx, buf)
}
}
impl AsyncSeek for FileSlot {
fn start_seek(mut self: Pin<&mut Self>, position: SeekFrom) -> Result<(), tokio::io::Error> {
Pin::new(&mut self.inner).start_seek(position)
}
fn poll_complete(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<u64, tokio::io::Error>> {
Pin::new(&mut self.inner).poll_complete(cx)
}
}
impl AsyncWrite for FileSlot {
fn poll_write(mut self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize, tokio::io::Error>> {
Pin::new(&mut self.inner).poll_write(cx, buf)
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), tokio::io::Error>> {
Pin::new(&mut self.inner).poll_flush(cx)
}
fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), tokio::io::Error>> {
Pin::new(&mut self.inner).poll_shutdown(cx)
}
fn poll_write_vectored(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>],
) -> Poll<Result<usize, tokio::io::Error>> {
Pin::new(&mut self.inner).poll_write_vectored(cx, bufs)
}
fn is_write_vectored(&self) -> bool {
self.inner.is_write_vectored()
}
}
const DEFAULT_OPEN_FILE_PERMITS: usize = 10;
static TOTAL_FILE_SEMAPHORES: AtomicUsize = AtomicUsize::new(DEFAULT_OPEN_FILE_PERMITS);
pub static OPEN_FILE_SEMAPHORE: Semaphore = Semaphore::const_new(DEFAULT_OPEN_FILE_PERMITS);
pub fn set_open_file_limit(limit: usize) {
let current_total = TOTAL_FILE_SEMAPHORES.load(Ordering::Acquire);
if limit < current_total {
log::error!("set_open_file_limit({}) must be greater than {}", limit, current_total);
return;
}
TOTAL_FILE_SEMAPHORES.fetch_add(limit - current_total, Ordering::Release);
OPEN_FILE_SEMAPHORE.add_permits(limit - current_total);
}
pub fn get_open_files_for_test() -> usize {
TOTAL_FILE_SEMAPHORES.load(Ordering::Acquire) - OPEN_FILE_SEMAPHORE.available_permits()
}
/// How long a file descriptor can be open without being used before it is closed.
static IDLE_FILE_DESCRIPTOR_TIMEOUT: OnceLock<Duration> = OnceLock::new();
pub fn idle_file_descriptor_timeout() -> Duration {
*IDLE_FILE_DESCRIPTOR_TIMEOUT.get_or_init(|| Duration::MAX)
}
/// Set the idle file descriptor timeout. This is the amount of time
/// a file descriptor can be open without being used before it is closed.
pub fn set_idle_file_descriptor_timeout(timeout: Duration) -> Result<(), Error> {
IDLE_FILE_DESCRIPTOR_TIMEOUT
.set(timeout)
.map_err(|_| make_err!(Code::Internal, "idle_file_descriptor_timeout already set"))
}
pub async fn open_file<'a>(path: impl Into<Cow<'a, OsStr>>, limit: u64) -> Result<ResumeableFileSlot<'a>, Error> {
let permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
let path = path.into();
Ok(ResumeableFileSlot::new_with_take(
FileSlot {
_permit: permit,
inner: tokio::fs::File::open(&path)
.await
.err_tip(|| format!("Could not open {:?}", path))?,
}
.take(limit),
path,
false, /* is_write */
))
}
pub async fn create_file<'a>(path: impl Into<Cow<'a, OsStr>>) -> Result<ResumeableFileSlot<'a>, Error> {
let permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
let path = path.into();
Ok(ResumeableFileSlot::new(
FileSlot {
_permit: permit,
inner: tokio::fs::File::create(&path)
.await
.err_tip(|| format!("Could not open {:?}", path))?,
},
path,
true, /* is_write */
))
}
pub async fn hard_link(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::hard_link(src, dst).await.map_err(|e| e.into())
}
pub async fn set_permissions(src: impl AsRef<Path>, perm: std::fs::Permissions) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::set_permissions(src, perm).await.map_err(|e| e.into())
}
pub async fn create_dir(path: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::create_dir(path).await.map_err(|e| e.into())
}
pub async fn create_dir_all(path: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::create_dir_all(path).await.map_err(|e| e.into())
}
#[cfg(target_family = "unix")]
pub async fn symlink(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::symlink(src, dst).await.map_err(|e| e.into())
}
pub async fn read_link(path: impl AsRef<Path>) -> Result<std::path::PathBuf, Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::read_link(path).await.map_err(|e| e.into())
}
pub struct ReadDir<'a> {
// We hold the permit because once it is dropped it goes back into the queue.
permit: SemaphorePermit<'a>,
inner: tokio::fs::ReadDir,
}
impl<'a> ReadDir<'a> {
pub fn into_inner(self) -> (SemaphorePermit<'a>, tokio::fs::ReadDir) {
(self.permit, self.inner)
}
}
impl<'a> AsRef<tokio::fs::ReadDir> for ReadDir<'a> {
fn as_ref(&self) -> &tokio::fs::ReadDir {
&self.inner
}
}
impl<'a> AsMut<tokio::fs::ReadDir> for ReadDir<'a> {
fn as_mut(&mut self) -> &mut tokio::fs::ReadDir {
&mut self.inner
}
}
pub async fn read_dir(path: impl AsRef<Path>) -> Result<ReadDir<'static>, Error> {
let permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
Ok(ReadDir {
permit,
inner: tokio::fs::read_dir(path).await.map_err(Into::<Error>::into)?,
})
}
pub async fn rename(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::rename(from, to).await.map_err(|e| e.into())
}
pub async fn remove_file(path: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::remove_file(path).await.map_err(|e| e.into())
}
pub async fn canonicalize(path: impl AsRef<Path>) -> Result<PathBuf, Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::canonicalize(path).await.map_err(|e| e.into())
}
pub async fn metadata(path: impl AsRef<Path>) -> Result<Metadata, Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::metadata(path).await.map_err(|e| e.into())
}
pub async fn read(path: impl AsRef<Path>) -> Result<Vec<u8>, Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::read(path).await.map_err(|e| e.into())
}
pub async fn symlink_metadata(path: impl AsRef<Path>) -> Result<Metadata, Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::symlink_metadata(path).await.map_err(|e| e.into())
}
pub async fn remove_dir_all(path: impl AsRef<Path>) -> Result<(), Error> {
let _permit = OPEN_FILE_SEMAPHORE
.acquire()
.await
.map_err(|e| make_err!(Code::Internal, "Open file semaphore closed {:?}", e))?;
tokio::fs::remove_dir_all(path).await.map_err(|e| e.into())
}