Refactor path splitting in router

src/wiki_lookup.rs

@@ -16,7 +16,7 @@ lazy_static! {
         let mut lookup_map = HashMap::new();
 
         lookup_map.insert(
-            "/_changes".to_string(),
+            "_changes".to_string(),
             Box::new(|state: &State|
                 // TODO Use query arguments to fill in the `before` parameter below
                 Box::new(ChangesResource::new(state.clone(), None)) as BoxResource
@@ -24,31 +24,31 @@ lazy_static! {
         );
 
         lookup_map.insert(
-            "/_sitemap".to_string(),
+            "_sitemap".to_string(),
             Box::new(|state: &State|
                 Box::new(SitemapResource::new(state.clone())) as BoxResource
             ) as ResourceFn
         );
 
         lookup_map.insert(
-            "/_new".to_string(),
+            "_new".to_string(),
             Box::new(|state: &State|
                 Box::new(NewArticleResource::new(state.clone(), None)) as BoxResource
             ) as ResourceFn
         );
 
         lookup_map.insert(
-            format!("/_assets/style-{}.css", StyleCss::checksum()),
+            format!("_assets/style-{}.css", StyleCss::checksum()),
             Box::new(|_: &State| Box::new(StyleCss) as BoxResource) as ResourceFn
         );
 
         lookup_map.insert(
-            format!("/_assets/script-{}.js", ScriptJs::checksum()),
+            format!("_assets/script-{}.js", ScriptJs::checksum()),
             Box::new(|_: &State| Box::new(ScriptJs) as BoxResource) as ResourceFn
         );
 
         lookup_map.insert(
-            format!("/_assets/amatic-sc-v9-latin-regular.woff"),
+            format!("_assets/amatic-sc-v9-latin-regular.woff"),
             Box::new(|_: &State| Box::new(AmaticFont) as BoxResource) as ResourceFn
         );
 
@@ -61,37 +61,33 @@ pub struct WikiLookup {
     state: State
 }
 
+fn split_one(path: &str) -> Result<(::std::borrow::Cow<str>, Option<&str>), ::std::str::Utf8Error> {
+    let mut split = path.splitn(2, '/');
+    let head = split.next().expect("At least one item must be returned");
+    let head = percent_decode(head.as_bytes()).decode_utf8()?;
+    let tail = split.next();
+
+    Ok((head, tail))
+}
+
 impl WikiLookup {
     pub fn new(state: State) -> WikiLookup {
         WikiLookup { state }
     }
-}
 
-impl Lookup for WikiLookup {
-    type Resource = BoxResource;
-    type Error = Box<::std::error::Error + Send + Sync>;
-    type Future = Box<Future<Item = Option<Self::Resource>, Error = Self::Error>>;
-
-    fn lookup(&self, path: &str, query: Option<&str>) -> Self::Future {
-        assert!(path.starts_with("/"));
-
-        if path.starts_with("/_") {
-            // Reserved namespace
-
-            return Box::new(finished(
+    fn reserved_lookup(&self, path: &str, _query: Option<&str>) -> <Self as Lookup>::Future {
+        Box::new(finished(
             LOOKUP_MAP.get(path).map(|x| x(&self.state))
-            ));
+        ))
     }
 
-        let mut split = path[1..].split('/');
-
-        let slug = split.next().expect("Always at least one element");
-        let slug = match percent_decode(slug.as_bytes()).decode_utf8() {
+    fn article_lookup(&self, path: &str, query: Option<&str>) -> <Self as Lookup>::Future {
+        let (slug, tail) = match split_one(path) {
             Ok(x) => x,
-            Err(x) => return Box::new(failed(x.into()))
-        }.to_string();
+            Err(x) => return Box::new(failed(x.into())),
+        };
 
-        if split.next() != None {
+        if tail.is_some() {
             // Currently disallow any URLs of the form /slug/...
             return Box::new(finished(None));
         }
@@ -106,6 +102,7 @@ impl Lookup for WikiLookup {
 
         let state = self.state.clone();
         let edit = query == Some("edit");
+        let slug = slug.into_owned();
 
         use state::SlugLookup;
         Box::new(self.state.lookup_slug(slug.clone())
@@ -120,3 +117,20 @@ impl Lookup for WikiLookup {
         )
     }
 }
+
+impl Lookup for WikiLookup {
+    type Resource = BoxResource;
+    type Error = Box<::std::error::Error + Send + Sync>;
+    type Future = Box<Future<Item = Option<Self::Resource>, Error = Self::Error>>;
+
+    fn lookup(&self, path: &str, query: Option<&str>) -> Self::Future {
+        assert!(path.starts_with("/"));
+        let path = &path[1..];
+
+        if path.starts_with("_") {
+            self.reserved_lookup(path, query)
+        } else {
+            self.article_lookup(path, query)
+        }
+    }
+}