cache trait accepts a bytestream instead

src/cache/low_mem.rs

@@ -7,17 +7,17 @@ use bytes::Bytes;
 use futures::Stream;
 use lru::LruCache;
 
-use super::{fs::FromFsStream, Cache, CacheKey};
+use super::{fs::FromFsStream, ByteStream, Cache, CacheKey};
 
 pub struct LowMemCache {
     on_disk: LruCache<CacheKey, ()>,
     disk_path: PathBuf,
-    disk_max_size: usize,
-    disk_cur_size: usize,
+    disk_max_size: u64,
+    disk_cur_size: u64,
 }
 
 impl LowMemCache {
-    pub fn new(disk_max_size: usize, disk_path: PathBuf) -> Self {
+    pub fn new(disk_max_size: u64, disk_path: PathBuf) -> Self {
         Self {
             on_disk: LruCache::unbounded(),
             disk_path,
@@ -37,10 +37,8 @@ impl Cache for LowMemCache {
         }
     }
 
-    async fn put_stream(
-        &mut self,
-        key: CacheKey,
-        image: impl Stream<Item = Result<Bytes, reqwest::Error>> + Unpin + Send + 'static,
-    ) {
+    async fn put_stream(&mut self, key: CacheKey, image: ByteStream) {
+        // this call has a side effect and the returned future is for reading
+        let _ = super::fs::transparent_file_stream(&PathBuf::from(key), image);
     }
 }

src/cache/mod.rs

@@ -131,7 +131,7 @@ impl ImageMetadata {
 }
 
 #[async_trait]
-pub trait Cache {
+pub trait Cache: Send + Sync {
     async fn get(&mut self, _key: &CacheKey) -> Option<&(CachedImage, ImageMetadata)> {
         unimplemented!()
     }
@@ -147,11 +147,20 @@ pub trait Cache {
         unimplemented!()
     }
 
-    async fn put_stream(
-        &mut self,
-        _key: CacheKey,
-        _image: impl Stream<Item = Result<Bytes, reqwest::Error>> + Unpin + Send + 'static,
-    ) {
+    async fn put_stream(&mut self, _key: CacheKey, _image: ByteStream) {
         unimplemented!()
     }
 }
+
+pub enum ByteStream {}
+
+impl Stream for ByteStream {
+    type Item = Result<Bytes, reqwest::Error>;
+
+    fn poll_next(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Option<Self::Item>> {
+        todo!()
+    }
+}

src/config.rs

@@ -34,6 +34,6 @@ pub struct CliArgs {
     /// reasons.
     #[clap(long, env = "ENABLE_SERVER_STRING", takes_value = false)]
     pub enable_server_string: bool,
-    #[clap(short, long, conflicts_with("memory_quota"))]
+    #[clap(short, long, conflicts_with("memory_quota"), env = "LOW_MEMORY_MODE")]
     pub low_memory: bool,
 }

src/main.rs

@@ -12,7 +12,7 @@ use std::{num::ParseIntError, sync::atomic::Ordering};
 use actix_web::rt::{spawn, time, System};
 use actix_web::web::{self, Data};
 use actix_web::{App, HttpServer};
-use cache::GenerationalCache;
+use cache::{Cache, GenerationalCache, LowMemCache};
 use clap::Clap;
 use config::CliArgs;
 use log::{debug, error, warn, LevelFilter};
@@ -54,6 +54,7 @@ async fn main() -> Result<(), std::io::Error> {
     let memory_max_size = cli_args.memory_quota.get();
     let disk_quota = cli_args.disk_quota;
     let cache_path = cli_args.cache_path.clone();
+    let low_mem_mode = cli_args.low_memory;
 
     SimpleLogger::new()
         .with_level(LevelFilter::Info)
@@ -106,16 +107,22 @@ async fn main() -> Result<(), std::io::Error> {
 
     // Start HTTPS server
     HttpServer::new(move || {
+        let cache: Box<dyn Cache> = if low_mem_mode {
+            Box::new(LowMemCache::new(disk_quota, cache_path.clone()))
+        } else {
+            Box::new(GenerationalCache::new(
+                memory_max_size,
+                disk_quota,
+                cache_path.clone(),
+            ))
+        };
+
         App::new()
             .service(routes::token_data)
             .service(routes::token_data_saver)
             .route("{tail:.*}", web::get().to(routes::default))
             .app_data(Data::from(Arc::clone(&data_1)))
-            .app_data(Data::new(Mutex::new(GenerationalCache::new(
-                memory_max_size,
-                disk_quota,
-                cache_path.clone(),
-            ))))
+            .app_data(Data::new(Mutex::new(cache)))
     })
     .shutdown_timeout(60)
     .bind_rustls(format!("0.0.0.0:{}", port), tls_config)?

src/routes.rs

@@ -18,7 +18,7 @@ use serde::Deserialize;
 use sodiumoxide::crypto::box_::{open_precomputed, Nonce, PrecomputedKey, NONCEBYTES};
 use thiserror::Error;
 
-use crate::cache::{Cache, CacheKey, CachedImage, GenerationalCache, ImageMetadata};
+use crate::cache::{Cache, CacheKey, CachedImage, ImageMetadata};
 use crate::client_api_version;
 use crate::config::{SEND_SERVER_VERSION, VALIDATE_TOKENS};
 use crate::state::RwLockServerState;
@@ -52,7 +52,7 @@ impl Responder for ServerResponse {
 #[get("/{token}/data/{chapter_hash}/{file_name}")]
 async fn token_data(
     state: Data<RwLockServerState>,
-    cache: Data<Mutex<GenerationalCache>>,
+    cache: Data<Mutex<Box<dyn Cache>>>,
     path: Path<(String, String, String)>,
 ) -> impl Responder {
     let (token, chapter_hash, file_name) = path.into_inner();
@@ -68,7 +68,7 @@ async fn token_data(
 #[get("/{token}/data-saver/{chapter_hash}/{file_name}")]
 async fn token_data_saver(
     state: Data<RwLockServerState>,
-    cache: Data<Mutex<GenerationalCache>>,
+    cache: Data<Mutex<Box<dyn Cache>>>,
     path: Path<(String, String, String)>,
 ) -> impl Responder {
     let (token, chapter_hash, file_name) = path.into_inner();
@@ -175,7 +175,7 @@ fn push_headers(builder: &mut HttpResponseBuilder) -> &mut HttpResponseBuilder {
 
 async fn fetch_image(
     state: Data<RwLockServerState>,
-    cache: Data<Mutex<GenerationalCache>>,
+    cache: Data<Mutex<Box<dyn Cache>>>,
     chapter_hash: String,
     file_name: String,
     is_data_saver: bool,