Caching (#480)

* add basic caching support

* Use hash of static dir instead of rand

* Add support for ETag

src/main.rs

@@ -189,6 +189,7 @@ Then try to restart Plume.
             routes::session::password_reset_form,
             routes::session::password_reset,
 
+            routes::plume_static_files,
             routes::static_files,
 
             routes::tags::tag,

src/routes/mod.rs

@@ -1,6 +1,9 @@
 use atom_syndication::{ContentBuilder, Entry, EntryBuilder, LinkBuilder, Person, PersonBuilder};
 use rocket::{
-    http::{RawStr, Status, uri::{FromUriParam, Query}},
+    http::{
+        RawStr, Status, uri::{FromUriParam, Query},
+        hyper::header::{CacheControl, CacheDirective}
+    },
     Outcome,
     request::{self, FromFormValue, FromRequest, Request},
     response::NamedFile,
@@ -101,7 +104,24 @@ pub mod user;
 pub mod search;
 pub mod well_known;
 
-#[get("/static/<file..>", rank = 2)]
-pub fn static_files(file: PathBuf) -> Option<NamedFile> {
-    NamedFile::open(Path::new("static/").join(file)).ok()
+#[derive(Responder)]
+#[response()]
+pub struct CachedFile {
+    inner: NamedFile,
+    cache_control: CacheControl
+}
+
+#[get("/static/cached/<_build_id>/<file..>", rank = 2)]
+pub fn plume_static_files(file: PathBuf, _build_id: &RawStr) -> Option<CachedFile> {
+    static_files(file)
+}
+
+#[get("/static/<file..>", rank = 3)]
+pub fn static_files(file: PathBuf) -> Option<CachedFile> {
+    NamedFile::open(Path::new("static/").join(file)).ok()
+        .map(|f|
+             CachedFile {
+                 inner: f,
+                 cache_control: CacheControl(vec![CacheDirective::MaxAge(60*60*24*30)])
+             })
 }

src/template_utils.rs

@@ -1,19 +1,50 @@
 use plume_models::{Connection, notifications::*, users::User};
-use rocket::response::Content;
+
+use rocket::http::{Method, Status};
+use rocket::http::hyper::header::{ETag, EntityTag};
+use rocket::request::Request;
+use rocket::response::{self, Response, Responder, content::Html as HtmlCt};
 use rocket_i18n::Catalog;
+use std::collections::hash_map::DefaultHasher;
+use std::hash::Hasher;
 use templates::Html;
 
 pub use askama_escape::escape;
 
+pub static CACHE_NAME: &str = env!("CACHE_ID");
+
 pub type BaseContext<'a> = &'a(&'a Connection, &'a Catalog, Option<User>);
 
-pub type Ructe = Content<Vec<u8>>;
+#[derive(Debug)]
+pub struct Ructe(pub Vec<u8>);
+
+impl<'r> Responder<'r> for Ructe {
+    fn respond_to(self, r: &Request) -> response::Result<'r> {
+        //if method is not Get or page contain a form, no caching
+        if r.method() != Method::Get || self.0.windows(6).any(|w| w == b"<form ") {
+            return HtmlCt(self.0).respond_to(r);
+        }
+        let mut hasher = DefaultHasher::new();
+        hasher.write(&self.0);
+        let etag = format!("{:x}", hasher.finish());
+        if r.headers().get("If-None-Match").any(|s| &s[1..s.len()-1] == etag) {
+            Response::build()
+                .status(Status::NotModified)
+                .header(ETag(EntityTag::strong(etag)))
+                .ok()
+        } else {
+            Response::build()
+                .merge(HtmlCt(self.0).respond_to(r)?)
+                .header(ETag(EntityTag::strong(etag)))
+                .ok()
+        }
+    }
+}
 
 #[macro_export]
 macro_rules! render {
     ($group:tt :: $page:tt ( $( $param:expr ),* ) ) => {
         {
-            use rocket::{http::ContentType, response::Content};
             use templates;
 
             let mut res = vec![];
@@ -23,7 +54,7 @@ macro_rules! render {
                     $param
                 ),*
             ).unwrap();
-            Content(ContentType::HTML, res)
+            Ructe(res)
         }
     }
 }