Extract cache into own crate

backend/Cargo.lock

@@ -659,6 +659,7 @@ dependencies = [
  "serde_derive 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
+ "time-cache 0.1.0",
 ]
 
 [[package]]
@@ -1602,6 +1603,10 @@ dependencies = [
  "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "time-cache"
+version = "0.1.0"
+
 [[package]]
 name = "tokio-codec"
 version = "0.1.1"

backend/Cargo.toml

@@ -19,3 +19,4 @@ serde = { version = "1.0.97", features = ["rc"] }
 serde_derive = "1.0.97"
 serde_json = "1.0.40"
 structopt = "0.2.18"
+time-cache = { path = "../time-cache" }

backend/src/cache.rs

@@ -1,90 +0,0 @@
-use crate::statics::REDIRECT_AGE;
-use std::{
-    collections::HashMap,
-    hash::Hash,
-    sync::Arc,
-    time::{Duration, Instant},
-};
-
-pub(crate) struct Cache<K, V> {
-    cache: HashMap<K, CacheEntry<V>>,
-    duration: Duration,
-}
-
-impl<K, V> Cache<K, V>
-where
-    K: Eq + Hash,
-{
-    pub(crate) fn new() -> Self {
-        Self {
-            cache: HashMap::new(),
-            duration: REDIRECT_AGE,
-        }
-    }
-
-    pub(crate) fn get(&self, key: &K) -> CacheResult<&V> {
-        if let Some(entry) = self.cache.get(key) {
-            if Self::is_valid(Instant::now(), entry) {
-                CacheResult::Cached(&entry.1)
-            } else {
-                CacheResult::Invalid
-            }
-        } else {
-            CacheResult::Empty
-        }
-    }
-
-    pub(crate) fn invalidate(&mut self, key: &K) -> bool {
-        self.cache.remove(key).is_some()
-    }
-
-    pub(crate) fn store(&mut self, key: K, value: V) -> Option<V> {
-        self.cache
-            .insert(key, CacheEntry::new(value, self.duration))
-            .map(|old| old.1)
-    }
-
-    pub(crate) fn clear(&mut self) {
-        let now = Instant::now();
-        self.cache.retain(|_, v| !Self::is_valid(now, v));
-    }
-
-    fn is_valid(when: Instant, entry: &CacheEntry<V>) -> bool {
-        entry.0 >= when
-    }
-}
-
-pub(crate) enum CacheResult<T> {
-    Cached(T),
-    Invalid,
-    Empty,
-}
-
-struct CacheEntry<T>(Instant, T);
-
-impl<T> CacheEntry<T> {
-    fn new(value: T, duration: Duration) -> Self {
-        CacheEntry(Instant::now() + duration, value)
-    }
-}
-
-#[derive(Eq, PartialEq, Hash, Debug)]
-pub(crate) struct Key(Service, Arc<String>, Arc<String>, Arc<String>);
-
-#[derive(Eq, PartialEq, Hash, Debug)]
-pub(crate) enum Service {
-    GitHub,
-    GitLab,
-    Bitbucket,
-}
-
-impl Key {
-    pub(crate) fn new(
-        service: Service,
-        user: Arc<String>,
-        repo: Arc<String>,
-        branch: Arc<String>,
-    ) -> Self {
-        Key(service, user, repo, branch)
-    }
-}

backend/src/data.rs

@@ -1,8 +1,6 @@
-use crate::{
+use crate::service;
-    cache::{Cache, Key},
-    service::Service,
-};
 use std::sync::{Arc, RwLock};
+use time_cache::Cache;
 
 pub(crate) type State = Arc<RwLock<Cache<Key, String>>>;
 
@@ -19,7 +17,7 @@ impl FilePath {
         format!("{}/{}/{}/{}", self.user, self.repo, self.commit, self.file)
     }
 
-    pub(crate) fn to_key<T: Service>(&self) -> Key {
+    pub(crate) fn to_key<T: service::Service>(&self) -> Key {
         Key::new(
             T::cache_service(),
             self.user.clone(),
@@ -28,3 +26,24 @@ impl FilePath {
         )
     }
 }
+
+#[derive(Eq, PartialEq, Hash, Debug)]
+pub(crate) struct Key(Service, Arc<String>, Arc<String>, Arc<String>);
+
+#[derive(Eq, PartialEq, Hash, Debug)]
+pub(crate) enum Service {
+    GitHub,
+    GitLab,
+    Bitbucket,
+}
+
+impl Key {
+    pub(crate) fn new(
+        service: Service,
+        user: Arc<String>,
+        repo: Arc<String>,
+        branch: Arc<String>,
+    ) -> Self {
+        Key(service, user, repo, branch)
+    }
+}

backend/src/main.rs

@@ -16,7 +16,6 @@ mod service;
 mod statics;
 
 use crate::{
-    cache::{Cache, CacheResult},
     cdn::Cloudflare,
     data::{FilePath, State},
     error::Result,
@@ -31,6 +30,7 @@ use actix_web::{
 use awc::{http::StatusCode, Client};
 use futures::Future;
 use std::sync::{Arc, RwLock};
+use time_cache::{Cache, CacheResult};
 
 fn proxy_file<T: Service>(
     client: web::Data<Client>,
@@ -210,7 +210,7 @@ fn main() -> Result<()> {
     pretty_env_logger::init();
     openssl_probe::init_ssl_cert_env_vars();
 
-    let state: State = Arc::new(RwLock::new(Cache::new()));
+    let state: State = Arc::new(RwLock::new(Cache::new(REDIRECT_AGE)));
     Ok(HttpServer::new(move || {
         App::new()
             .data(Client::new())

backend/src/service.rs

@@ -1,6 +1,5 @@
 use crate::{
-    cache,
+    data::{self, FilePath, State},
-    data::{FilePath, State},
     statics::{load_env_var, GITHUB_AUTH_QUERY, OPT, REDIRECT_AGE},
 };
 use actix_web::{
@@ -71,7 +70,7 @@ pub(crate) trait Service: Sized {
 
     fn raw_url(user: &str, repo: &str, commit: &str, file: &str) -> String;
 
-    fn cache_service() -> cache::Service;
+    fn cache_service() -> data::Service;
 
     fn api_url(path: &FilePath) -> String;
 
@@ -141,8 +140,8 @@ impl Github {
 impl Service for Github {
     type Response = GitHubApiResponse;
 
-    fn cache_service() -> cache::Service {
+    fn cache_service() -> data::Service {
-        cache::Service::GitHub
+        data::Service::GitHub
     }
 
     fn path() -> &'static str {
@@ -176,8 +175,8 @@ pub(crate) struct Bitbucket;
 impl Service for Bitbucket {
     type Response = BitbucketApiResponse;
 
-    fn cache_service() -> cache::Service {
+    fn cache_service() -> data::Service {
-        cache::Service::Bitbucket
+        data::Service::Bitbucket
     }
 
     fn path() -> &'static str {
@@ -208,8 +207,8 @@ pub(crate) struct GitLab;
 impl Service for GitLab {
     type Response = GitLabApiResponse;
 
-    fn cache_service() -> cache::Service {
+    fn cache_service() -> data::Service {
-        cache::Service::GitLab
+        data::Service::GitLab
     }
 
     fn path() -> &'static str {

time-cache/.gitignore

@@ -0,0 +1,3 @@
+/target
+**/*.rs.bk
+Cargo.lock

time-cache/Cargo.lock

@@ -0,0 +1,6 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "time-cache"
+version = "0.1.0"
+

time-cache/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "time-cache"
+version = "0.1.0"
+authors = ["Valentin Brandl <vbrandl@riseup.net>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

time-cache/src/lib.rs

@@ -0,0 +1,74 @@
+use std::{
+    collections::HashMap,
+    hash::Hash,
+    time::{Duration, Instant},
+};
+
+pub struct Cache<K, V> {
+    cache: HashMap<K, CacheEntry<V>>,
+    duration: Duration,
+}
+
+impl<K, V> Cache<K, V>
+where
+    K: Eq + Hash,
+{
+    pub fn new(duration: Duration) -> Self {
+        Self {
+            cache: HashMap::new(),
+            duration,
+        }
+    }
+
+    pub fn get(&self, key: &K) -> CacheResult<&V> {
+        if let Some(entry) = self.cache.get(key) {
+            if Self::is_valid(Instant::now(), entry) {
+                CacheResult::Cached(&entry.1)
+            } else {
+                CacheResult::Invalid
+            }
+        } else {
+            CacheResult::Empty
+        }
+    }
+
+    pub fn invalidate(&mut self, key: &K) -> bool {
+        self.cache.remove(key).is_some()
+    }
+
+    pub fn store(&mut self, key: K, value: V) -> Option<V> {
+        self.cache
+            .insert(key, CacheEntry::new(value, self.duration))
+            .map(|old| old.1)
+    }
+
+    pub fn clear(&mut self) {
+        let now = Instant::now();
+        self.cache.retain(|_, v| !Self::is_valid(now, v));
+    }
+
+    fn is_valid(when: Instant, entry: &CacheEntry<V>) -> bool {
+        entry.0 >= when
+    }
+}
+
+pub enum CacheResult<T> {
+    Cached(T),
+    Invalid,
+    Empty,
+}
+
+struct CacheEntry<T>(Instant, T);
+
+impl<T> CacheEntry<T> {
+    fn new(value: T, duration: Duration) -> Self {
+        CacheEntry(Instant::now() + duration, value)
+    }
+}
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}