use std::io::{Read, Seek, SeekFrom, Write};
use syscall::error::{Error, Result, EIO};
use crate::disk::Disk;
use crate::BLOCK_SIZE;
macro_rules! try_disk {
($expr:expr) => {
match $expr {
Ok(val) => val,
Err(err) => {
eprintln!("Disk I/O Error: {}", err);
return Err(Error::new(EIO));
}
}
};
}
pub struct DiskIo<T>(pub T);
impl<T: Read + Write + Seek> Disk for DiskIo<T> {
unsafe fn read_at(&mut self, block: u64, buffer: &mut [u8]) -> Result<usize> {
try_disk!(self.0.seek(SeekFrom::Start(block * BLOCK_SIZE)));
let count = try_disk!(self.0.read(buffer));
Ok(count)
}
unsafe fn write_at(&mut self, block: u64, buffer: &[u8]) -> Result<usize> {
try_disk!(self.0.seek(SeekFrom::Start(block * BLOCK_SIZE)));
let count = try_disk!(self.0.write(buffer));
Ok(count)
}
fn size(&mut self) -> Result<u64> {
let size = try_disk!(self.0.seek(SeekFrom::End(0)));
Ok(size)
}
}