Files
wasmtime/crates/wasi-common/src/sys/unix/fd.rs

78 lines
2.9 KiB
Rust

use super::oshandle::RawOsHandle;
use crate::handle::{Advice, Dircookie, Dirent, Fdflags, Filesize, Filestat, DIRCOOKIE_START};
use crate::sys::osdir::OsDir;
use crate::sys::osfile::OsFile;
use crate::Result;
use std::convert::TryInto;
use std::fs::File;
use std::os::unix::prelude::AsRawFd;
pub(crate) fn fdstat_get(fd: &File) -> Result<Fdflags> {
let fdflags = unsafe { yanix::fcntl::get_status_flags(fd.as_raw_fd())? };
Ok(fdflags.into())
}
pub(crate) fn fdstat_set_flags(fd: &File, fdflags: Fdflags) -> Result<Option<RawOsHandle>> {
unsafe { yanix::fcntl::set_status_flags(fd.as_raw_fd(), fdflags.into())? };
// We return None here to signal that the operation succeeded on the original
// file descriptor and mutating the original WASI Descriptor is thus unnecessary.
// This is needed as on Windows this operation required reopening a file.
Ok(None)
}
pub(crate) fn advise(file: &OsFile, advice: Advice, offset: Filesize, len: Filesize) -> Result<()> {
use yanix::fadvise::{posix_fadvise, PosixFadviseAdvice};
let offset = offset.try_into()?;
let len = len.try_into()?;
let host_advice = match advice {
Advice::Dontneed => PosixFadviseAdvice::DontNeed,
Advice::Sequential => PosixFadviseAdvice::Sequential,
Advice::Willneed => PosixFadviseAdvice::WillNeed,
Advice::Noreuse => PosixFadviseAdvice::NoReuse,
Advice::Random => PosixFadviseAdvice::Random,
Advice::Normal => PosixFadviseAdvice::Normal,
};
unsafe { posix_fadvise(file.as_raw_fd(), offset, len, host_advice)? };
Ok(())
}
pub(crate) fn filestat_get(file: &File) -> Result<Filestat> {
use yanix::file::fstat;
let stat = unsafe { fstat(file.as_raw_fd())? };
Ok(stat.try_into()?)
}
pub(crate) fn readdir<'a>(
dirfd: &'a OsDir,
cookie: Dircookie,
) -> Result<Box<dyn Iterator<Item = Result<(Dirent, String)>> + 'a>> {
use yanix::dir::{DirIter, Entry, EntryExt, SeekLoc};
// Get an instance of `Dir`; this is host-specific due to intricasies
// of managing a dir stream between Linux and BSD *nixes
let mut dir = dirfd.stream_ptr()?;
// Seek if needed. Unless cookie is wasi::__WASI_DIRCOOKIE_START,
// new items may not be returned to the caller.
if cookie == DIRCOOKIE_START {
tracing::trace!("fd_readdir: doing rewinddir");
dir.rewind();
} else {
tracing::trace!("fd_readdir: doing seekdir to {}", cookie);
let loc = unsafe { SeekLoc::from_raw(cookie as i64)? };
dir.seek(loc);
}
Ok(Box::new(DirIter::new(dir).map(|entry| {
let entry: Entry = entry?;
let name = entry.file_name().to_str()?.to_owned();
let dirent = Dirent {
d_next: entry.seek_loc()?.to_raw().try_into()?,
d_ino: entry.ino(),
d_namlen: name.len().try_into()?,
d_type: entry.file_type().into(),
};
Ok((dirent, name))
})))
}