Files
RedBear-OS/src/fs.rs
T

157 lines
4.0 KiB
Rust

use crate::{
c_str::CStr,
error::{Errno, ResultExt},
header::{
fcntl::O_CREAT,
sys_stat::stat,
unistd::{SEEK_CUR, SEEK_END, SEEK_SET},
},
io,
out::Out,
platform::{Pal, Sys, types::*},
};
use core::ops::Deref;
pub struct File {
pub fd: c_int,
/// To avoid self referential FILE struct that needs both a reader and a writer,
/// make "reference" files that share fd but don't close on drop.
pub reference: bool,
}
impl File {
pub fn new(fd: c_int) -> Self {
Self {
fd,
reference: false,
}
}
pub fn open(path: CStr, oflag: c_int) -> Result<Self, Errno> {
Sys::open(path, oflag, 0)
.map(Self::new)
.map_err(Errno::sync)
}
pub fn openat(dirfd: c_int, path: CStr, oflag: c_int) -> Result<Self, Errno> {
Sys::openat(dirfd, path, oflag, 0)
.map(Self::new)
.map_err(Errno::sync)
}
pub fn create(path: CStr, oflag: c_int, mode: mode_t) -> Result<Self, Errno> {
Sys::open(path, oflag | O_CREAT, mode)
.map(Self::new)
.map_err(Errno::sync)
}
pub fn createat(dirfd: c_int, path: CStr, oflag: c_int, mode: mode_t) -> Result<Self, Errno> {
Sys::openat(dirfd, path, oflag | O_CREAT, mode)
.map(Self::new)
.map_err(Errno::sync)
}
pub fn sync_all(&self) -> Result<(), Errno> {
Sys::fsync(self.fd).map_err(Errno::sync)
}
pub fn set_len(&self, size: u64) -> Result<(), Errno> {
Sys::ftruncate(self.fd, size as off_t).map_err(Errno::sync)
}
pub fn fstat(&self) -> Result<stat, Errno> {
let mut file_st = stat::default();
Sys::fstat(self.fd, Out::from_mut(&mut file_st)).map_err(Errno::sync)?;
Ok(file_st)
}
pub fn try_clone(&self) -> io::Result<Self> {
Ok(Self::new(Sys::dup(self.fd)?))
}
/// Create a new file pointing to the same underlying descriptor. This file
/// will know it's a "reference" and won't close the fd. It will, however,
/// not prevent the original file from closing the fd.
pub unsafe fn get_ref(&self) -> Self {
Self {
fd: self.fd,
reference: true,
}
}
}
impl io::Read for &File {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
match Sys::read(self.fd, buf).map(|read| read as ssize_t).or_minus_one_errno() /* TODO */ {
-1 => Err(io::last_os_error()),
ok => Ok(ok as usize),
}
}
}
impl io::Write for &File {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
match Sys::write(self.fd, buf)
.map(|read| read as ssize_t)
.or_minus_one_errno()
{
-1 => Err(io::last_os_error()),
ok => Ok(ok as usize),
}
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
impl io::Seek for &File {
fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
let (offset, whence) = match pos {
io::SeekFrom::Start(start) => (start as off_t, SEEK_SET),
io::SeekFrom::Current(current) => (current as off_t, SEEK_CUR),
io::SeekFrom::End(end) => (end as off_t, SEEK_END),
};
Ok(Sys::lseek(self.fd, offset, whence)? as u64)
}
}
impl io::Read for File {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(&mut &*self).read(buf)
}
}
impl io::Write for File {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
(&mut &*self).write(buf)
}
fn flush(&mut self) -> io::Result<()> {
(&mut &*self).flush()
}
}
impl io::Seek for File {
fn seek(&mut self, pos: io::SeekFrom) -> io::Result<u64> {
(&mut &*self).seek(pos)
}
}
impl Deref for File {
type Target = c_int;
fn deref(&self) -> &Self::Target {
&self.fd
}
}
impl Drop for File {
fn drop(&mut self) {
if !self.reference {
let _ = Sys::close(self.fd);
}
}
}