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 = 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() => {} } }