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//! WASI-specific extensions to primitives in the `std::fs` module.
#![unstable(feature = "wasi_ext", issue = "0")]
use crate::fs::{self, File, Metadata, OpenOptions};
use crate::io::{self, IoSlice, IoSliceMut};
use crate::os::wasi::ffi::OsStrExt;
use crate::path::{Path, PathBuf};
use crate::sys_common::{AsInner, AsInnerMut, FromInner};
/// WASI-specific extensions to [`File`].
///
/// [`File`]: ../../../../std/fs/struct.File.html
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_vectored`], it is not an error to
/// return with a short read.
///
/// [`File::read`]: ../../../../std/fs/struct.File.html#method.read_vectored
fn read_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize>;
/// 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.
///
/// [`File::write`]: ../../../../std/fs/struct.File.html#method.write_vectored
fn write_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize>;
/// Returns the current position within the file.
///
/// This corresponds to the `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_fd_allocate` syscall.
fn allocate(&self, offset: u64, len: u64) -> io::Result<()>;
/// Create a directory.
///
/// This corresponds to the `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_path_unlink_file` syscall.
fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
/// Remove a directory.
///
/// This corresponds to the `__wasi_path_remove_directory` syscall.
fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
}
// FIXME: bind __wasi_fd_fdstat_get - need to define a custom return type
// FIXME: bind __wasi_fd_readdir - can't return `ReadDir` since we only have entry name
// FIXME: bind __wasi_fd_filestat_set_times maybe? - on crates.io for unix
// FIXME: bind __wasi_path_filestat_set_times maybe? - on crates.io for unix
// FIXME: bind __wasi_poll_oneoff maybe? - probably should wait for I/O to settle
// FIXME: bind __wasi_random_get maybe? - on crates.io for unix
impl FileExt for fs::File {
fn read_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
self.as_inner().fd().pread(bufs, offset)
}
fn write_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
self.as_inner().fd().pwrite(bufs, offset)
}
fn tell(&self) -> io::Result<u64> {
self.as_inner().fd().tell()
}
fn fdstat_set_flags(&self, flags: u16) -> io::Result<()> {
self.as_inner().fd().set_flags(flags)
}
fn fdstat_set_rights(&self, rights: u64, inheriting: u64) -> io::Result<()> {
self.as_inner().fd().set_rights(rights, inheriting)
}
fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()> {
self.as_inner().fd().advise(offset, len, advice)
}
fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
self.as_inner().fd().allocate(offset, len)
}
fn create_directory<P: AsRef<Path>>(&self, dir: P) -> io::Result<()> {
self.as_inner()
.fd()
.create_directory(dir.as_ref().as_os_str().as_bytes())
}
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()
.fd()
.unlink_file(path.as_ref().as_os_str().as_bytes())
}
fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
self.as_inner()
.fd()
.remove_directory(path.as_ref().as_os_str().as_bytes())
}
}
/// WASI-specific extensions to [`fs::OpenOptions`].
///
/// [`fs::OpenOptions`]: ../../../../std/fs/struct.OpenOptions.html
pub trait OpenOptionsExt {
/// Pass custom `dirflags` argument to `__wasi_path_open`.
///
/// This option configures the `dirflags` argument to the
/// `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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 `__wasi_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`].
///
/// [`fs::Metadata`]: ../../../../std/fs/struct.Metadata.html
pub trait MetadataExt {
/// Returns the `st_dev` field of the internal `__wasi_filestat_t`
fn dev(&self) -> u64;
/// Returns the `st_ino` field of the internal `__wasi_filestat_t`
fn ino(&self) -> u64;
/// Returns the `st_nlink` field of the internal `__wasi_filestat_t`
fn nlink(&self) -> u32;
/// Returns the `st_atim` field of the internal `__wasi_filestat_t`
fn atim(&self) -> u64;
/// Returns the `st_mtim` field of the internal `__wasi_filestat_t`
fn mtim(&self) -> u64;
/// Returns the `st_ctim` field of the internal `__wasi_filestat_t`
fn ctim(&self) -> u64;
}
impl MetadataExt for fs::Metadata {
fn dev(&self) -> u64 {
self.as_inner().as_wasi().st_dev
}
fn ino(&self) -> u64 {
self.as_inner().as_wasi().st_ino
}
fn nlink(&self) -> u32 {
self.as_inner().as_wasi().st_nlink
}
fn atim(&self) -> u64 {
self.as_inner().as_wasi().st_atim
}
fn mtim(&self) -> u64 {
self.as_inner().as_wasi().st_mtim
}
fn ctim(&self) -> u64 {
self.as_inner().as_wasi().st_ctim
}
}
/// WASI-specific extensions for [`FileType`].
///
/// Adds support for special WASI file types such as block/character devices,
/// pipes, and sockets.
///
/// [`FileType`]: ../../../../std/fs/struct.FileType.html
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_character_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;
}
impl FileTypeExt for fs::FileType {
fn is_block_device(&self) -> bool {
self.as_inner().bits() == libc::__WASI_FILETYPE_BLOCK_DEVICE
}
fn is_character_device(&self) -> bool {
self.as_inner().bits() == libc::__WASI_FILETYPE_CHARACTER_DEVICE
}
fn is_socket_dgram(&self) -> bool {
self.as_inner().bits() == libc::__WASI_FILETYPE_SOCKET_DGRAM
}
fn is_socket_stream(&self) -> bool {
self.as_inner().bits() == libc::__WASI_FILETYPE_SOCKET_STREAM
}
}
/// WASI-specific extension methods for [`fs::DirEntry`].
///
/// [`fs::DirEntry`]: ../../../../std/fs/struct.DirEntry.html
pub trait DirEntryExt {
/// Returns the underlying `d_ino` field of the `__wasi_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 `__wasi_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().fd().link(
old_flags,
old_path.as_ref().as_os_str().as_bytes(),
new_fd.as_inner().fd(),
new_path.as_ref().as_os_str().as_bytes(),
)
}
/// Rename a file or directory.
///
/// This corresponds to the `__wasi_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().fd().rename(
old_path.as_ref().as_os_str().as_bytes(),
new_fd.as_inner().fd(),
new_path.as_ref().as_os_str().as_bytes(),
)
}
/// Create a symbolic link.
///
/// This corresponds to the `__wasi_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().fd().symlink(
old_path.as_ref().as_os_str().as_bytes(),
new_path.as_ref().as_os_str().as_bytes(),
)
}
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