garage/src/util/persister.rs

87 lines
1.8 KiB
Rust

use std::io::{Read, Write};
use std::path::{Path, PathBuf};
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use crate::error::Error;
use crate::migrate::Migrate;
pub struct Persister<T: Migrate> {
path: PathBuf,
_marker: std::marker::PhantomData<T>,
}
impl<T: Migrate> Persister<T> {
pub fn new(base_dir: &Path, file_name: &str) -> Self {
let mut path = base_dir.to_path_buf();
path.push(file_name);
Self {
path,
_marker: Default::default(),
}
}
fn decode(&self, bytes: &[u8]) -> Result<T, Error> {
match T::decode(bytes) {
Some(v) => Ok(v),
None => {
error!(
"Unable to decode persisted data file {}",
self.path.display()
);
for line in hexdump::hexdump_iter(bytes) {
debug!("{}", line);
}
Err(Error::Message(format!(
"Unable to decode persisted data file {}",
self.path.display()
)))
}
}
}
pub fn load(&self) -> Result<T, Error> {
let mut file = std::fs::OpenOptions::new().read(true).open(&self.path)?;
let mut bytes = vec![];
file.read_to_end(&mut bytes)?;
let value = self.decode(&bytes[..])?;
Ok(value)
}
pub fn save(&self, t: &T) -> Result<(), Error> {
let bytes = t.encode()?;
let mut file = std::fs::OpenOptions::new()
.write(true)
.create(true)
.truncate(true)
.open(&self.path)?;
file.write_all(&bytes[..])?;
Ok(())
}
pub async fn load_async(&self) -> Result<T, Error> {
let mut file = tokio::fs::File::open(&self.path).await?;
let mut bytes = vec![];
file.read_to_end(&mut bytes).await?;
let value = self.decode(&bytes[..])?;
Ok(value)
}
pub async fn save_async(&self, t: &T) -> Result<(), Error> {
let bytes = t.encode()?;
let mut file = tokio::fs::File::create(&self.path).await?;
file.write_all(&bytes[..]).await?;
Ok(())
}
}