use std::{
fs,
io::{self, Read},
ops::{AddAssign, Deref, DerefMut},
path::Path,
};
use brk_core::{Error, Result};
use zerocopy::{FromBytes, IntoBytes};
use zerocopy_derive::{FromBytes, Immutable, IntoBytes, KnownLayout};
#[derive(
Debug,
Default,
Clone,
Copy,
PartialEq,
Eq,
PartialOrd,
Ord,
FromBytes,
IntoBytes,
Immutable,
KnownLayout,
)]
pub struct Length(usize);
impl Length {
pub fn write(&self, path: &Path) -> Result<(), io::Error> {
fs::write(path, self.as_bytes())
}
}
impl From<usize> for Length {
fn from(value: usize) -> Self {
Self(value)
}
}
impl Deref for Length {
type Target = usize;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl DerefMut for Length {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.0
}
}
impl TryFrom<&Path> for Length {
type Error = Error;
fn try_from(value: &Path) -> Result<Self, Self::Error> {
let mut buf = [0; 8];
if let Ok(bytes) = fs::read(value) {
bytes.as_slice().read_exact(&mut buf)?;
Ok(*(Self::ref_from_bytes(&buf)?))
} else {
Ok(Self::default())
}
}
}
impl AddAssign<usize> for Length {
fn add_assign(&mut self, rhs: usize) {
self.0 += rhs;
}
}