tweak and document router (actix#2612)

Co-authored-by: Rob Ede <[email protected]>

actix-router/CHANGES.md

@@ -1,8 +1,14 @@
 # Changes
 
 ## Unreleased - 2021-xx-xx
+- Remove unused `ResourceInfo`. [#2612]
+- Add `RouterBuilder::push`. [#2612]
+- Change signature of `ResourceDef::capture_match_info_fn` to remove `user_data` parameter. [#2612]
+- Replace `Option<U>` with `U` in `Router` API. [#2612]
+- Relax bounds on `Router::recognize*` and `ResourceDef::capture_match_info`. [#2612]
 - `Quoter::requote` now returns `Option<Vec<u8>>`. [#2613]
 
+[#2612]: https://github.com/actix/actix-web/pull/2612
 [#2613]: https://github.com/actix/actix-web/pull/2613
 
 

actix-router/src/lib.rs

@@ -22,7 +22,7 @@ pub use self::pattern::{IntoPatterns, Patterns};
 pub use self::quoter::Quoter;
 pub use self::resource::ResourceDef;
 pub use self::resource_path::{Resource, ResourcePath};
-pub use self::router::{ResourceInfo, Router, RouterBuilder};
+pub use self::router::{ResourceId, Router, RouterBuilder};
 
 #[cfg(feature = "http")]
 pub use self::url::Url;

actix-router/src/quoter.rs

@@ -64,14 +64,14 @@ impl Quoter {
         quoter
     }
 
-    /// Re-quotes... ?
+    /// Decodes safe percent-encoded sequences from `val`.
     ///
     /// Returns `None` when no modification to the original byte string was required.
     ///
     /// Non-ASCII bytes are accepted as valid input.
     ///
-    /// Behavior for invalid/incomplete percent-encoding sequences is unspecified and may include removing
-    /// the invalid sequence from the output or passing it as it is.
+    /// Behavior for invalid/incomplete percent-encoding sequences is unspecified and may include
+    /// removing the invalid sequence from the output or passing it as-is.
     pub fn requote(&self, val: &[u8]) -> Option<Vec<u8>> {
         let mut has_pct = 0;
         let mut pct = [b'%', 0, 0];

actix-router/src/resource.rs

@@ -8,10 +8,7 @@ use std::{
 use firestorm::{profile_fn, profile_method, profile_section};
 use regex::{escape, Regex, RegexSet};
 
-use crate::{
-    path::{Path, PathItem},
-    IntoPatterns, Patterns, Resource, ResourcePath,
-};
+use crate::{path::PathItem, IntoPatterns, Patterns, Resource, ResourcePath};
 
 const MAX_DYNAMIC_SEGMENTS: usize = 16;
 
@@ -615,7 +612,7 @@ impl ResourceDef {
         }
     }
 
-    /// Collects dynamic segment values into `path`.
+    /// Collects dynamic segment values into `resource`.
     ///
     /// Returns `true` if `path` matches this resource.
     ///
@@ -635,9 +632,9 @@ impl ResourceDef {
     /// assert_eq!(path.get("path").unwrap(), "HEAD/Cargo.toml");
     /// assert_eq!(path.unprocessed(), "");
     /// ```
-    pub fn capture_match_info<T: ResourcePath>(&self, path: &mut Path<T>) -> bool {
+    pub fn capture_match_info<R: Resource>(&self, resource: &mut R) -> bool {
         profile_method!(capture_match_info);
-        self.capture_match_info_fn(path, |_, _| true, ())
+        self.capture_match_info_fn(resource, |_| true)
     }
 
     /// Collects dynamic segment values into `resource` after matching paths and executing
@@ -655,13 +652,12 @@ impl ResourceDef {
     /// use actix_router::{Path, ResourceDef};
     ///
     /// fn try_match(resource: &ResourceDef, path: &mut Path<&str>) -> bool {
-    ///     let admin_allowed = std::env::var("ADMIN_ALLOWED").ok();
+    ///     let admin_allowed = std::env::var("ADMIN_ALLOWED").is_ok();
     ///
     ///     resource.capture_match_info_fn(
     ///         path,
     ///         // when env var is not set, reject when path contains "admin"
-    ///         |res, admin_allowed| !res.path().contains("admin"),
-    ///         &admin_allowed
+    ///         |res| !(!admin_allowed && res.path().contains("admin")),
     ///     )
     /// }
     ///
@@ -678,15 +674,10 @@ impl ResourceDef {
     /// assert!(!try_match(&resource, &mut path));
     /// assert_eq!(path.unprocessed(), "/user/admin/stars");
     /// ```
-    pub fn capture_match_info_fn<R, F, U>(
-        &self,
-        resource: &mut R,
-        check_fn: F,
-        user_data: U,
-    ) -> bool
+    pub fn capture_match_info_fn<R, F>(&self, resource: &mut R, check_fn: F) -> bool
     where
         R: Resource,
-        F: FnOnce(&R, U) -> bool,
+        F: FnOnce(&R) -> bool,
     {
         profile_method!(capture_match_info_fn);
 
@@ -762,7 +753,7 @@ impl ResourceDef {
             }
         };
 
-        if !check_fn(resource, user_data) {
+        if !check_fn(resource) {
             return false;
         }
 
@@ -857,7 +848,7 @@ impl ResourceDef {
         S: BuildHasher,
     {
         profile_method!(resource_path_from_map);
-        self.build_resource_path(path, |name| values.get(name).map(AsRef::<str>::as_ref))
+        self.build_resource_path(path, |name| values.get(name))
     }
 
     /// Returns true if `prefix` acts as a proper prefix (i.e., separated by a slash) in `path`.
@@ -1157,6 +1148,7 @@ pub(crate) fn insert_slash(path: &str) -> Cow<'_, str> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::Path;
 
     #[test]
     fn equivalence() {

actix-router/src/router.rs

@@ -5,134 +5,150 @@ use crate::{IntoPatterns, Resource, ResourceDef};
 #[derive(Debug, Copy, Clone, PartialEq)]
 pub struct ResourceId(pub u16);
 
-/// Information about current resource
-#[derive(Debug, Clone)]
-pub struct ResourceInfo {
-    #[allow(dead_code)]
-    resource: ResourceId,
-}
-
 /// Resource router.
-// T is the resource itself
-// U is any other data needed for routing like method guards
+///
+/// It matches a [routing resource](Resource) to an ordered list of _routes_. Each is defined by a
+/// single [`ResourceDef`] and contains two types of custom data:
+/// 1. The route _value_, of the generic type `T`.
+/// 1. Some _context_ data, of the generic type `U`, which is only provided to the check function in
+///    [`recognize_fn`](Self::recognize_fn). This parameter defaults to `()` and can be omitted if
+///    not required.
 pub struct Router<T, U = ()> {
-    routes: Vec<(ResourceDef, T, Option<U>)>,
+    routes: Vec<(ResourceDef, T, U)>,
 }
 
 impl<T, U> Router<T, U> {
+    /// Constructs new `RouterBuilder` with empty route list.
     pub fn build() -> RouterBuilder<T, U> {
-        RouterBuilder {
-            resources: Vec::new(),
-        }
+        RouterBuilder { routes: Vec::new() }
     }
 
+    /// Finds the value in the router that matches a given [routing resource](Resource).
+    ///
+    /// The match result, including the captured dynamic segments, in the `resource`.
     pub fn recognize<R>(&self, resource: &mut R) -> Option<(&T, ResourceId)>
     where
         R: Resource,
     {
         profile_method!(recognize);
-
-        for item in self.routes.iter() {
-            if item.0.capture_match_info(resource.resource_path()) {
-                return Some((&item.1, ResourceId(item.0.id())));
-            }
-        }
-
-        None
+        self.recognize_fn(resource, |_, _| true)
     }
 
+    /// Same as [`recognize`](Self::recognize) but returns a mutable reference to the matched value.
     pub fn recognize_mut<R>(&mut self, resource: &mut R) -> Option<(&mut T, ResourceId)>
     where
         R: Resource,
     {
         profile_method!(recognize_mut);
-
-        for item in self.routes.iter_mut() {
-            if item.0.capture_match_info(resource.resource_path()) {
-                return Some((&mut item.1, ResourceId(item.0.id())));
-            }
-        }
-
-        None
+        self.recognize_mut_fn(resource, |_, _| true)
     }
 
-    pub fn recognize_fn<R, F>(&self, resource: &mut R, check: F) -> Option<(&T, ResourceId)>
+    /// Finds the value in the router that matches a given [routing resource](Resource) and passes
+    /// an additional predicate check using context data.
+    ///
+    /// Similar to [`recognize`](Self::recognize). However, before accepting the route as matched,
+    /// the `check` closure is executed, passing the resource and each route's context data. If the
+    /// closure returns true then the match result is stored into `resource` and a reference to
+    /// the matched _value_ is returned.
+    pub fn recognize_fn<R, F>(&self, resource: &mut R, mut check: F) -> Option<(&T, ResourceId)>
     where
-        F: Fn(&R, &Option<U>) -> bool,
         R: Resource,
+        F: FnMut(&R, &U) -> bool,
     {
         profile_method!(recognize_checked);
 
-        for item in self.routes.iter() {
-            if item.0.capture_match_info_fn(resource, &check, &item.2) {
-                return Some((&item.1, ResourceId(item.0.id())));
+        for (rdef, val, ctx) in self.routes.iter() {
+            if rdef.capture_match_info_fn(resource, |res| check(res, ctx)) {
+                return Some((val, ResourceId(rdef.id())));
             }
         }
 
         None
     }
 
+    /// Same as [`recognize_fn`](Self::recognize_fn) but returns a mutable reference to the matched
+    /// value.
     pub fn recognize_mut_fn<R, F>(
         &mut self,
         resource: &mut R,
-        check: F,
+        mut check: F,
     ) -> Option<(&mut T, ResourceId)>
     where
-        F: Fn(&R, &Option<U>) -> bool,
         R: Resource,
+        F: FnMut(&R, &U) -> bool,
     {
         profile_method!(recognize_mut_checked);
 
-        for item in self.routes.iter_mut() {
-            if item.0.capture_match_info_fn(resource, &check, &item.2) {
-                return Some((&mut item.1, ResourceId(item.0.id())));
+        for (rdef, val, ctx) in self.routes.iter_mut() {
+            if rdef.capture_match_info_fn(resource, |res| check(res, ctx)) {
+                return Some((val, ResourceId(rdef.id())));
             }
         }
 
         None
     }
 }
 
+/// Builder for an ordered [routing](Router) list.
 pub struct RouterBuilder<T, U = ()> {
-    resources: Vec<(ResourceDef, T, Option<U>)>,
+    routes: Vec<(ResourceDef, T, U)>,
 }
 
 impl<T, U> RouterBuilder<T, U> {
-    /// Register resource for specified path.
-    pub fn path<P: IntoPatterns>(
+    /// Adds a new route to the end of the routing list.
+    ///
+    /// Returns mutable references to elements of the new route.
+    pub fn push(
         &mut self,
-        path: P,
-        resource: T,
-    ) -> &mut (ResourceDef, T, Option<U>) {
-        profile_method!(path);
-
-        self.resources
-            .push((ResourceDef::new(path), resource, None));
-        self.resources.last_mut().unwrap()
+        rdef: ResourceDef,
+        val: T,
+        ctx: U,
+    ) -> (&mut ResourceDef, &mut T, &mut U) {
+        profile_method!(push);
+        self.routes.push((rdef, val, ctx));
+        self.routes
+            .last_mut()
+            .map(|(rdef, val, ctx)| (rdef, val, ctx))
+            .unwrap()
     }
 
-    /// Register resource for specified path prefix.
-    pub fn prefix(&mut self, prefix: &str, resource: T) -> &mut (ResourceDef, T, Option<U>) {
-        profile_method!(prefix);
-
-        self.resources
-            .push((ResourceDef::prefix(prefix), resource, None));
-        self.resources.last_mut().unwrap()
+    /// Finish configuration and create router instance.
+    pub fn finish(self) -> Router<T, U> {
+        Router {
+            routes: self.routes,
+        }
     }
+}
 
-    /// Register resource for ResourceDef
-    pub fn rdef(&mut self, rdef: ResourceDef, resource: T) -> &mut (ResourceDef, T, Option<U>) {
-        profile_method!(rdef);
+/// Convenience methods provided when context data impls [`Default`]
+impl<T, U> RouterBuilder<T, U>
+where
+    U: Default,
+{
+    /// Registers resource for specified path.
+    pub fn path(
+        &mut self,
+        path: impl IntoPatterns,
+        val: T,
+    ) -> (&mut ResourceDef, &mut T, &mut U) {
+        profile_method!(path);
+        self.push(ResourceDef::new(path), val, U::default())
+    }
 
-        self.resources.push((rdef, resource, None));
-        self.resources.last_mut().unwrap()
+    /// Registers resource for specified path prefix.
+    pub fn prefix(
+        &mut self,
+        prefix: impl IntoPatterns,
+        val: T,
+    ) -> (&mut ResourceDef, &mut T, &mut U) {
+        profile_method!(prefix);
+        self.push(ResourceDef::prefix(prefix), val, U::default())
     }
 
-    /// Finish configuration and create router instance.
-    pub fn finish(self) -> Router<T, U> {
-        Router {
-            routes: self.resources,
-        }
+    /// Registers resource for [`ResourceDef`].
+    pub fn rdef(&mut self, rdef: ResourceDef, val: T) -> (&mut ResourceDef, &mut T, &mut U) {
+        profile_method!(rdef);
+        self.push(rdef, val, U::default())
     }
 }