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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558
//! WASI-specific extensions to primitives in the [`std::fs`] module.
//!
//! [`std::fs`]: crate::fs
#![deny(unsafe_op_in_unsafe_fn)]
#![unstable(feature = "wasi_ext", issue = "71213")]
use crate::ffi::OsStr;
use crate::fs::{self, File, Metadata, OpenOptions};
use crate::io::{self, IoSlice, IoSliceMut};
use crate::path::{Path, PathBuf};
use crate::sys_common::{AsInner, AsInnerMut, FromInner};
// Used for `File::read` on intra-doc links
#[allow(unused_imports)]
use io::{Read, Write};
/// WASI-specific extensions to [`File`].
pub trait FileExt {
/// Reads a number of bytes starting from a given offset.
///
/// Returns the number of bytes read.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// Note that similar to [`File::read`], it is not an error to return with a
/// short read.
fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
let bufs = &mut [IoSliceMut::new(buf)];
self.read_vectored_at(bufs, offset)
}
/// Reads a number of bytes starting from a given offset.
///
/// Returns the number of bytes read.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// Note that similar to [`File::read_vectored`], it is not an error to
/// return with a short read.
fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize>;
/// Reads the exact number of byte required to fill `buf` from the given offset.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// Similar to [`Read::read_exact`] but uses [`read_at`] instead of `read`.
///
/// [`read_at`]: FileExt::read_at
///
/// # Errors
///
/// If this function encounters an error of the kind
/// [`io::ErrorKind::Interrupted`] then the error is ignored and the operation
/// will continue.
///
/// If this function encounters an "end of file" before completely filling
/// the buffer, it returns an error of the kind [`io::ErrorKind::UnexpectedEof`].
/// The contents of `buf` are unspecified in this case.
///
/// If any other read error is encountered then this function immediately
/// returns. The contents of `buf` are unspecified in this case.
///
/// If this function returns an error, it is unspecified how many bytes it
/// has read, but it will never read more than would be necessary to
/// completely fill the buffer.
#[stable(feature = "rw_exact_all_at", since = "1.33.0")]
fn read_exact_at(&self, mut buf: &mut [u8], mut offset: u64) -> io::Result<()> {
while !buf.is_empty() {
match self.read_at(buf, offset) {
Ok(0) => break,
Ok(n) => {
let tmp = buf;
buf = &mut tmp[n..];
offset += n as u64;
}
Err(ref e) if e.is_interrupted() => {}
Err(e) => return Err(e),
}
}
if !buf.is_empty() {
Err(io::const_io_error!(io::ErrorKind::UnexpectedEof, "failed to fill whole buffer"))
} else {
Ok(())
}
}
/// Writes a number of bytes starting from a given offset.
///
/// Returns the number of bytes written.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// When writing beyond the end of the file, the file is appropriately
/// extended and the intermediate bytes are initialized with the value 0.
///
/// Note that similar to [`File::write`], it is not an error to return a
/// short write.
fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
let bufs = &[IoSlice::new(buf)];
self.write_vectored_at(bufs, offset)
}
/// Writes a number of bytes starting from a given offset.
///
/// Returns the number of bytes written.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// When writing beyond the end of the file, the file is appropriately
/// extended and the intermediate bytes are initialized with the value 0.
///
/// Note that similar to [`File::write_vectored`], it is not an error to return a
/// short write.
fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize>;
/// Attempts to write an entire buffer starting from a given offset.
///
/// The offset is relative to the start of the file and thus independent
/// from the current cursor.
///
/// The current file cursor is not affected by this function.
///
/// This method will continuously call [`write_at`] until there is no more data
/// to be written or an error of non-[`io::ErrorKind::Interrupted`] kind is
/// returned. This method will not return until the entire buffer has been
/// successfully written or such an error occurs. The first error that is
/// not of [`io::ErrorKind::Interrupted`] kind generated from this method will be
/// returned.
///
/// # Errors
///
/// This function will return the first error of
/// non-[`io::ErrorKind::Interrupted`] kind that [`write_at`] returns.
///
/// [`write_at`]: FileExt::write_at
#[stable(feature = "rw_exact_all_at", since = "1.33.0")]
fn write_all_at(&self, mut buf: &[u8], mut offset: u64) -> io::Result<()> {
while !buf.is_empty() {
match self.write_at(buf, offset) {
Ok(0) => {
return Err(io::const_io_error!(
io::ErrorKind::WriteZero,
"failed to write whole buffer",
));
}
Ok(n) => {
buf = &buf[n..];
offset += n as u64
}
Err(ref e) if e.is_interrupted() => {}
Err(e) => return Err(e),
}
}
Ok(())
}
/// Returns the current position within the file.
///
/// This corresponds to the `fd_tell` syscall and is similar to
/// `seek` where you offset 0 bytes from the current position.
fn tell(&self) -> io::Result<u64>;
/// Adjust the flags associated with this file.
///
/// This corresponds to the `fd_fdstat_set_flags` syscall.
fn fdstat_set_flags(&self, flags: u16) -> io::Result<()>;
/// Adjust the rights associated with this file.
///
/// This corresponds to the `fd_fdstat_set_rights` syscall.
fn fdstat_set_rights(&self, rights: u64, inheriting: u64) -> io::Result<()>;
/// Provide file advisory information on a file descriptor.
///
/// This corresponds to the `fd_advise` syscall.
fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()>;
/// Force the allocation of space in a file.
///
/// This corresponds to the `fd_allocate` syscall.
fn allocate(&self, offset: u64, len: u64) -> io::Result<()>;
/// Create a directory.
///
/// This corresponds to the `path_create_directory` syscall.
fn create_directory<P: AsRef<Path>>(&self, dir: P) -> io::Result<()>;
/// Read the contents of a symbolic link.
///
/// This corresponds to the `path_readlink` syscall.
fn read_link<P: AsRef<Path>>(&self, path: P) -> io::Result<PathBuf>;
/// Return the attributes of a file or directory.
///
/// This corresponds to the `path_filestat_get` syscall.
fn metadata_at<P: AsRef<Path>>(&self, lookup_flags: u32, path: P) -> io::Result<Metadata>;
/// Unlink a file.
///
/// This corresponds to the `path_unlink_file` syscall.
fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
/// Remove a directory.
///
/// This corresponds to the `path_remove_directory` syscall.
fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
}
// FIXME: bind fd_fdstat_get - need to define a custom return type
// FIXME: bind fd_readdir - can't return `ReadDir` since we only have entry name
// FIXME: bind fd_filestat_set_times maybe? - on crates.io for unix
// FIXME: bind path_filestat_set_times maybe? - on crates.io for unix
// FIXME: bind poll_oneoff maybe? - probably should wait for I/O to settle
// FIXME: bind random_get maybe? - on crates.io for unix
impl FileExt for fs::File {
fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
self.as_inner().as_inner().pread(bufs, offset)
}
fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
self.as_inner().as_inner().pwrite(bufs, offset)
}
fn tell(&self) -> io::Result<u64> {
self.as_inner().as_inner().tell()
}
fn fdstat_set_flags(&self, flags: u16) -> io::Result<()> {
self.as_inner().as_inner().set_flags(flags)
}
fn fdstat_set_rights(&self, rights: u64, inheriting: u64) -> io::Result<()> {
self.as_inner().as_inner().set_rights(rights, inheriting)
}
fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()> {
let advice = match advice {
a if a == wasi::ADVICE_NORMAL.raw() => wasi::ADVICE_NORMAL,
a if a == wasi::ADVICE_SEQUENTIAL.raw() => wasi::ADVICE_SEQUENTIAL,
a if a == wasi::ADVICE_RANDOM.raw() => wasi::ADVICE_RANDOM,
a if a == wasi::ADVICE_WILLNEED.raw() => wasi::ADVICE_WILLNEED,
a if a == wasi::ADVICE_DONTNEED.raw() => wasi::ADVICE_DONTNEED,
a if a == wasi::ADVICE_NOREUSE.raw() => wasi::ADVICE_NOREUSE,
_ => {
return Err(io::const_io_error!(
io::ErrorKind::InvalidInput,
"invalid parameter 'advice'",
));
}
};
self.as_inner().as_inner().advise(offset, len, advice)
}
fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
self.as_inner().as_inner().allocate(offset, len)
}
fn create_directory<P: AsRef<Path>>(&self, dir: P) -> io::Result<()> {
self.as_inner().as_inner().create_directory(osstr2str(dir.as_ref().as_ref())?)
}
fn read_link<P: AsRef<Path>>(&self, path: P) -> io::Result<PathBuf> {
self.as_inner().read_link(path.as_ref())
}
fn metadata_at<P: AsRef<Path>>(&self, lookup_flags: u32, path: P) -> io::Result<Metadata> {
let m = self.as_inner().metadata_at(lookup_flags, path.as_ref())?;
Ok(FromInner::from_inner(m))
}
fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
self.as_inner().as_inner().unlink_file(osstr2str(path.as_ref().as_ref())?)
}
fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
self.as_inner().as_inner().remove_directory(osstr2str(path.as_ref().as_ref())?)
}
}
/// WASI-specific extensions to [`fs::OpenOptions`].
pub trait OpenOptionsExt {
/// Pass custom `dirflags` argument to `path_open`.
///
/// This option configures the `dirflags` argument to the
/// `path_open` syscall which `OpenOptions` will eventually call. The
/// `dirflags` argument configures how the file is looked up, currently
/// primarily affecting whether symlinks are followed or not.
///
/// By default this value is `__WASI_LOOKUP_SYMLINK_FOLLOW`, or symlinks are
/// followed. You can call this method with 0 to disable following symlinks
fn lookup_flags(&mut self, flags: u32) -> &mut Self;
/// Indicates whether `OpenOptions` must open a directory or not.
///
/// This method will configure whether the `__WASI_O_DIRECTORY` flag is
/// passed when opening a file. When passed it will require that the opened
/// path is a directory.
///
/// This option is by default `false`
fn directory(&mut self, dir: bool) -> &mut Self;
/// Indicates whether `__WASI_FDFLAG_DSYNC` is passed in the `fs_flags`
/// field of `path_open`.
///
/// This option is by default `false`
fn dsync(&mut self, dsync: bool) -> &mut Self;
/// Indicates whether `__WASI_FDFLAG_NONBLOCK` is passed in the `fs_flags`
/// field of `path_open`.
///
/// This option is by default `false`
fn nonblock(&mut self, nonblock: bool) -> &mut Self;
/// Indicates whether `__WASI_FDFLAG_RSYNC` is passed in the `fs_flags`
/// field of `path_open`.
///
/// This option is by default `false`
fn rsync(&mut self, rsync: bool) -> &mut Self;
/// Indicates whether `__WASI_FDFLAG_SYNC` is passed in the `fs_flags`
/// field of `path_open`.
///
/// This option is by default `false`
fn sync(&mut self, sync: bool) -> &mut Self;
/// Indicates the value that should be passed in for the `fs_rights_base`
/// parameter of `path_open`.
///
/// This option defaults based on the `read` and `write` configuration of
/// this `OpenOptions` builder. If this method is called, however, the
/// exact mask passed in will be used instead.
fn fs_rights_base(&mut self, rights: u64) -> &mut Self;
/// Indicates the value that should be passed in for the
/// `fs_rights_inheriting` parameter of `path_open`.
///
/// The default for this option is the same value as what will be passed
/// for the `fs_rights_base` parameter but if this method is called then
/// the specified value will be used instead.
fn fs_rights_inheriting(&mut self, rights: u64) -> &mut Self;
/// Open a file or directory.
///
/// This corresponds to the `path_open` syscall.
fn open_at<P: AsRef<Path>>(&self, file: &File, path: P) -> io::Result<File>;
}
impl OpenOptionsExt for OpenOptions {
fn lookup_flags(&mut self, flags: u32) -> &mut OpenOptions {
self.as_inner_mut().lookup_flags(flags);
self
}
fn directory(&mut self, dir: bool) -> &mut OpenOptions {
self.as_inner_mut().directory(dir);
self
}
fn dsync(&mut self, enabled: bool) -> &mut OpenOptions {
self.as_inner_mut().dsync(enabled);
self
}
fn nonblock(&mut self, enabled: bool) -> &mut OpenOptions {
self.as_inner_mut().nonblock(enabled);
self
}
fn rsync(&mut self, enabled: bool) -> &mut OpenOptions {
self.as_inner_mut().rsync(enabled);
self
}
fn sync(&mut self, enabled: bool) -> &mut OpenOptions {
self.as_inner_mut().sync(enabled);
self
}
fn fs_rights_base(&mut self, rights: u64) -> &mut OpenOptions {
self.as_inner_mut().fs_rights_base(rights);
self
}
fn fs_rights_inheriting(&mut self, rights: u64) -> &mut OpenOptions {
self.as_inner_mut().fs_rights_inheriting(rights);
self
}
fn open_at<P: AsRef<Path>>(&self, file: &File, path: P) -> io::Result<File> {
let inner = file.as_inner().open_at(path.as_ref(), self.as_inner())?;
Ok(File::from_inner(inner))
}
}
/// WASI-specific extensions to [`fs::Metadata`].
pub trait MetadataExt {
/// Returns the `st_dev` field of the internal `filestat_t`
fn dev(&self) -> u64;
/// Returns the `st_ino` field of the internal `filestat_t`
fn ino(&self) -> u64;
/// Returns the `st_nlink` field of the internal `filestat_t`
fn nlink(&self) -> u64;
/// Returns the `st_size` field of the internal `filestat_t`
fn size(&self) -> u64;
/// Returns the `st_atim` field of the internal `filestat_t`
fn atim(&self) -> u64;
/// Returns the `st_mtim` field of the internal `filestat_t`
fn mtim(&self) -> u64;
/// Returns the `st_ctim` field of the internal `filestat_t`
fn ctim(&self) -> u64;
}
impl MetadataExt for fs::Metadata {
fn dev(&self) -> u64 {
self.as_inner().as_wasi().dev
}
fn ino(&self) -> u64 {
self.as_inner().as_wasi().ino
}
fn nlink(&self) -> u64 {
self.as_inner().as_wasi().nlink
}
fn size(&self) -> u64 {
self.as_inner().as_wasi().size
}
fn atim(&self) -> u64 {
self.as_inner().as_wasi().atim
}
fn mtim(&self) -> u64 {
self.as_inner().as_wasi().mtim
}
fn ctim(&self) -> u64 {
self.as_inner().as_wasi().ctim
}
}
/// WASI-specific extensions for [`fs::FileType`].
///
/// Adds support for special WASI file types such as block/character devices,
/// pipes, and sockets.
pub trait FileTypeExt {
/// Returns `true` if this file type is a block device.
fn is_block_device(&self) -> bool;
/// Returns `true` if this file type is a character device.
fn is_char_device(&self) -> bool;
/// Returns `true` if this file type is a socket datagram.
fn is_socket_dgram(&self) -> bool;
/// Returns `true` if this file type is a socket stream.
fn is_socket_stream(&self) -> bool;
/// Returns `true` if this file type is any type of socket.
fn is_socket(&self) -> bool {
self.is_socket_stream() || self.is_socket_dgram()
}
}
impl FileTypeExt for fs::FileType {
fn is_block_device(&self) -> bool {
self.as_inner().bits() == wasi::FILETYPE_BLOCK_DEVICE
}
fn is_char_device(&self) -> bool {
self.as_inner().bits() == wasi::FILETYPE_CHARACTER_DEVICE
}
fn is_socket_dgram(&self) -> bool {
self.as_inner().bits() == wasi::FILETYPE_SOCKET_DGRAM
}
fn is_socket_stream(&self) -> bool {
self.as_inner().bits() == wasi::FILETYPE_SOCKET_STREAM
}
}
/// WASI-specific extension methods for [`fs::DirEntry`].
pub trait DirEntryExt {
/// Returns the underlying `d_ino` field of the `dirent_t`
fn ino(&self) -> u64;
}
impl DirEntryExt for fs::DirEntry {
fn ino(&self) -> u64 {
self.as_inner().ino()
}
}
/// Create a hard link.
///
/// This corresponds to the `path_link` syscall.
pub fn link<P: AsRef<Path>, U: AsRef<Path>>(
old_fd: &File,
old_flags: u32,
old_path: P,
new_fd: &File,
new_path: U,
) -> io::Result<()> {
old_fd.as_inner().as_inner().link(
old_flags,
osstr2str(old_path.as_ref().as_ref())?,
new_fd.as_inner().as_inner(),
osstr2str(new_path.as_ref().as_ref())?,
)
}
/// Rename a file or directory.
///
/// This corresponds to the `path_rename` syscall.
pub fn rename<P: AsRef<Path>, U: AsRef<Path>>(
old_fd: &File,
old_path: P,
new_fd: &File,
new_path: U,
) -> io::Result<()> {
old_fd.as_inner().as_inner().rename(
osstr2str(old_path.as_ref().as_ref())?,
new_fd.as_inner().as_inner(),
osstr2str(new_path.as_ref().as_ref())?,
)
}
/// Create a symbolic link.
///
/// This corresponds to the `path_symlink` syscall.
pub fn symlink<P: AsRef<Path>, U: AsRef<Path>>(
old_path: P,
fd: &File,
new_path: U,
) -> io::Result<()> {
fd.as_inner()
.as_inner()
.symlink(osstr2str(old_path.as_ref().as_ref())?, osstr2str(new_path.as_ref().as_ref())?)
}
/// Create a symbolic link.
///
/// This is a convenience API similar to `std::os::unix::fs::symlink` and
/// `std::os::windows::fs::symlink_file` and `std::os::windows::fs::symlink_dir`.
pub fn symlink_path<P: AsRef<Path>, U: AsRef<Path>>(old_path: P, new_path: U) -> io::Result<()> {
crate::sys::fs::symlink(old_path.as_ref(), new_path.as_ref())
}
fn osstr2str(f: &OsStr) -> io::Result<&str> {
f.to_str()
.ok_or_else(|| io::const_io_error!(io::ErrorKind::Uncategorized, "input must be utf-8"))
}