datatrash/src/deleter.rs

52 lines
1.9 KiB
Rust

use async_std::{fs, path::PathBuf, sync::Receiver, task};
use chrono::{prelude::*, Duration};
use futures::future::FutureExt;
use sqlx::{postgres::PgPool, Cursor, Row};
pub(crate) async fn delete_old_files(receiver: Receiver<()>, db: PgPool, files_dir: PathBuf) {
loop {
wait_for_file_expiry(&receiver, &db).await;
let now = Local::now().naive_local();
let mut cursor = sqlx::query("SELECT file_id FROM files WHERE files.valid_till < $1")
.bind(now)
.fetch(&db);
while let Some(row) = cursor.next().await.expect("could not load expired files") {
let file_id: String = row.get("file_id");
let mut path = files_dir.clone();
path.push(&file_id);
if path.exists().await {
log::info!("delete file {}", file_id);
fs::remove_file(&path).await.expect("could not delete file");
}
}
sqlx::query("DELETE FROM files WHERE valid_till < $1")
.bind(now)
.execute(&db)
.await
.expect("could not delete expired files from database");
}
}
async fn wait_for_file_expiry(receiver: &Receiver<()>, db: &PgPool) {
let mut cursor = sqlx::query("SELECT MIN(valid_till) as min from files").fetch(db);
let row = cursor
.next()
.await
.expect("could not fetch expiring files from database")
.expect("postgres min did not return any row");
let valid_till: Option<NaiveDateTime> = row.get("min");
let next_timeout = match valid_till {
Some(valid_till) => valid_till.signed_duration_since(Local::now().naive_local()),
None => Duration::days(1),
};
let positive_timeout = next_timeout
.to_std()
.unwrap_or_else(|_| std::time::Duration::from_secs(0));
futures::select! {
_ = task::sleep(positive_timeout).fuse() => {}
_ = receiver.recv().fuse() => {}
}
}