Files
wasmtime/crates/wasi-common/yanix/src/filetime.rs

79 lines
3.0 KiB
Rust

//! This module consists of helper types and functions for dealing
//! with setting the file times (mainly in `path_filestat_set_times` syscall for now).
//!
//! The vast majority of the code contained within and in platform-specific implementations
//! (`super::linux::filetime` and `super::bsd::filetime`) is based on the [filetime] crate.
//! Kudos @alexcrichton!
//!
//! [filetime]: https://github.com/alexcrichton/filetime
use std::io::Result;
pub use super::sys::filetime::*;
/// Internal trait which specialises `filetime::FileTime`'s
/// `seconds` and `nanoseconds` accessors for different
/// pointer widths (32 and 64bit currently).
pub(crate) trait FileTimeExt {
fn seconds_(&self) -> Result<libc::time_t>;
fn nanoseconds_(&self) -> libc::c_long;
}
impl FileTimeExt for filetime::FileTime {
fn seconds_(&self) -> Result<libc::time_t> {
use std::convert::TryInto;
use std::io::Error;
let sec = match self.seconds().try_into() {
Ok(sec) => sec,
Err(_) => {
tracing::debug!("filetime_to_timespec failed converting seconds to required width");
return Err(Error::from_raw_os_error(libc::EOVERFLOW));
}
};
Ok(sec)
}
fn nanoseconds_(&self) -> libc::c_long {
use std::convert::TryInto;
// According to [filetime] docs, since the nanoseconds value is always less than 1 billion,
// any value should be convertible to `libc::c_long`, hence we can `unwrap` outright.
//
// [filetime]: https://docs.rs/filetime/0.2.8/filetime/struct.FileTime.html#method.nanoseconds
self.nanoseconds().try_into().unwrap()
}
}
/// A wrapper `enum` around `filetime::FileTime` struct, but unlike the original, this
/// type allows the possibility of specifying `FileTime::Now` as a valid enumeration which,
/// in turn, if `utimensat` is available on the host, will use a special const setting
/// `UTIME_NOW`.
#[derive(Debug, Copy, Clone)]
pub enum FileTime {
Now,
Omit,
FileTime(filetime::FileTime),
}
/// Converts `FileTime` to `libc::timespec`. If `FileTime::Now` variant is specified, this
/// resolves to `UTIME_NOW` special const, `FileTime::Omit` variant resolves to `UTIME_OMIT`, and
/// `FileTime::FileTime(ft)` where `ft := filetime::FileTime` uses [filetime] crate's original
/// implementation which can be found here: [filetime::unix::to_timespec].
///
/// [filetime]: https://github.com/alexcrichton/filetime
/// [filetime::unix::to_timespec]: https://github.com/alexcrichton/filetime/blob/master/src/unix/mod.rs#L30
pub(crate) fn to_timespec(ft: &FileTime) -> Result<libc::timespec> {
let ts = match ft {
FileTime::Now => libc::timespec {
tv_sec: 0,
tv_nsec: libc::UTIME_NOW,
},
FileTime::Omit => libc::timespec {
tv_sec: 0,
tv_nsec: libc::UTIME_OMIT,
},
FileTime::FileTime(ft) => libc::timespec {
tv_sec: ft.seconds_()?,
tv_nsec: ft.nanoseconds_(),
},
};
Ok(ts)
}