refactor: migrate web server to Actix Web

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.toml

@@ -14,29 +14,32 @@ edition = "2021"
 [dependencies]
 badge = { path = "./libs/badge" }
 
+actix-web = "4"
+actix-web-lab = "0.20"
 anyhow = "1"
 cadence = "1"
-crates-index = { version = "2", default-features = false, features = ["git"] }
+crates-index = { version = "3", default-features = false, features = ["git"] }
-derive_more = "0.99"
+derive_more = { version = "1", features = ["display", "error", "from"] }
 dotenvy = "0.15"
+either = "1.12"
 font-awesome-as-a-crate = "0.3"
 futures-util = { version = "0.3", default-features = false, features = ["std"] }
-hyper = { version = "0.14.10", features = ["full"] }
 error_reporter = "1"
 indexmap = { version = "2", features = ["serde"] }
 lru_time_cache = "0.11"
 maud = "0.26"
+mime = "0.3"
 once_cell = "1"
 parking_lot = "0.12"
-pulldown-cmark = "0.11"
+pulldown-cmark = "0.12"
 relative-path = { version = "1", features = ["serde"] }
 reqwest = { version = "0.12", features = ["json"] }
-route-recognizer = "0.3"
 rustsec = "0.29"
-semver = { version = "1.0", features = ["serde"] }
+semver = { version = "1", features = ["serde"] }
 serde = { version = "1", features = ["derive"] }
 serde_urlencoded = "0.7"
-tokio = { version = "1.24.2", features = ["rt-multi-thread", "macros", "sync", "time"] }
+serde_with = "3"
+tokio = { version = "1.24.2", features = ["rt", "macros", "sync", "time"] }
 toml = "0.8"
 tracing = "0.1.30"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

README.md

@@ -19,10 +19,15 @@ To analyze the state of your dependencies you can use the following URLs:
 
 On the analysis page, you will also find the markdown code to include a fancy badge in your project README so visitors (and you) can see at a glance if your dependencies are still up to date!
 
-Badges have a few style options, specified with query parameters, that match the styles from `shields.io`:
+Badges have a few options, specified with query parameters:
+- `style`: which matches the styles from `shields.io`:
   - `?style=flat` (default)
   - `?style=flat-square`
   - `?style=for-the-badge`
+- `subject`: customize the text on the left (which is the same concept as `label` in `shields.io`, and [URL-Encoding](https://developer.mozilla.org/en-US/docs/Glossary/percent-encoding) is needed for spaces or special characters!). e.g.:
+  - `?subject=yourdeps`
+  - `?subject=git%20deps`
+  - `?subject=deps%3Acore`
 
 ## Contributing
 

src/engine/fut/crawl.rs

@@ -1,5 +1,7 @@
 use anyhow::Error;
-use futures_util::{future::BoxFuture, stream::FuturesOrdered, FutureExt as _, StreamExt as _};
+use futures_util::{
+    future::LocalBoxFuture, stream::FuturesOrdered, FutureExt as _, StreamExt as _,
+};
 use relative_path::RelativePathBuf;
 
 use crate::{
@@ -16,8 +18,9 @@ pub async fn crawl_manifest(
     entry_point: RelativePathBuf,
 ) -> anyhow::Result<ManifestCrawlerOutput> {
     let mut crawler = ManifestCrawler::new();
-    let mut futures: FuturesOrdered<BoxFuture<'static, Result<(RelativePathBuf, String), Error>>> =
+    let mut futures: FuturesOrdered<
-        FuturesOrdered::new();
+        LocalBoxFuture<'static, Result<(RelativePathBuf, String), Error>>,
+    > = FuturesOrdered::new();
 
     let engine2 = engine.clone();
     let repo_path2 = repo_path.clone();
@@ -28,7 +31,7 @@ pub async fn crawl_manifest(
             .await?;
         Ok((entry_point, contents))
     }
-    .boxed();
+    .boxed_local();
 
     futures.push_back(fut);
 
@@ -47,7 +50,7 @@ pub async fn crawl_manifest(
                 let contents = engine.retrieve_manifest_at_path(&repo_path, &path).await?;
                 Ok((path, contents))
             }
-            .boxed();
+            .boxed_local();
 
             futures.push_back(fut);
         }

src/engine/mod.rs

@@ -5,14 +5,14 @@ use std::{
     time::{Duration, Instant},
 };
 
+use actix_web::dev::Service;
 use anyhow::{anyhow, Error};
 use cadence::{MetricSink, NopMetricSink, StatsdClient};
 use futures_util::{
     future::try_join_all,
-    stream::{self, BoxStream},
+    stream::{self, LocalBoxStream},
     StreamExt as _,
 };
-use hyper::service::Service;
 use once_cell::sync::Lazy;
 use relative_path::{RelativePath, RelativePathBuf};
 use rustsec::database::Database;
@@ -38,7 +38,7 @@ mod machines;
 
 use self::fut::{analyze_dependencies, crawl_manifest};
 
-#[derive(Clone, Debug)]
+#[derive(Debug, Clone)]
 pub struct Engine {
     metrics: Arc<StatsdClient>,
     query_crate: Cache<QueryCrate, CrateName>,
@@ -255,7 +255,10 @@ impl Engine {
         Ok(latest)
     }
 
-    fn fetch_releases<'a, I>(&'a self, names: I) -> BoxStream<'a, anyhow::Result<Vec<CrateRelease>>>
+    fn fetch_releases<'a, I>(
+        &'a self,
+        names: I,
+    ) -> LocalBoxStream<'a, anyhow::Result<Vec<CrateRelease>>>
     where
         I: IntoIterator<Item = CrateName>,
         <I as IntoIterator>::IntoIter: Send + 'a,
@@ -277,7 +280,7 @@ impl Engine {
     ) -> Result<String, Error> {
         let manifest_path = path.join(RelativePath::new("Cargo.toml"));
 
-        let mut service = self.retrieve_file_at_path.clone();
+        let service = self.retrieve_file_at_path.clone();
         service.call((repo_path.clone(), manifest_path)).await
     }
 

src/interactors/crates.rs

@@ -1,19 +1,16 @@
-use std::{
+use std::{fmt, str};
-    fmt, str,
-    task::{Context, Poll},
-};
 
+use actix_web::dev::Service;
 use anyhow::{anyhow, Error};
 use crates_index::{Crate, DependencyKind};
-use futures_util::FutureExt as _;
+use futures_util::{future::LocalBoxFuture, FutureExt as _};
-use hyper::service::Service;
 use semver::{Version, VersionReq};
 use serde::Deserialize;
 use tokio::task::spawn_blocking;
 
 use crate::{
     models::crates::{CrateDep, CrateDeps, CrateName, CratePath, CrateRelease},
-    BoxFuture, ManagedIndex,
+    ManagedIndex,
 };
 
 const CRATES_API_BASE_URI: &str = "https://crates.io/api/v1";
@@ -86,13 +83,11 @@ impl fmt::Debug for QueryCrate {
 impl Service<CrateName> for QueryCrate {
     type Response = QueryCrateResponse;
     type Error = Error;
-    type Future = BoxFuture<Result<Self::Response, Self::Error>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    actix_web::dev::always_ready!();
-        Poll::Ready(Ok(()))
-    }
 
-    fn call(&mut self, crate_name: CrateName) -> Self::Future {
+    fn call(&self, crate_name: CrateName) -> Self::Future {
         let index = self.index.clone();
         Self::query(index, crate_name).boxed()
     }
@@ -150,13 +145,11 @@ impl fmt::Debug for GetPopularCrates {
 impl Service<()> for GetPopularCrates {
     type Response = Vec<CratePath>;
     type Error = Error;
-    type Future = BoxFuture<Result<Self::Response, Self::Error>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    actix_web::dev::always_ready!();
-        Poll::Ready(Ok(()))
-    }
 
-    fn call(&mut self, _req: ()) -> Self::Future {
+    fn call(&self, _req: ()) -> Self::Future {
         let client = self.client.clone();
         Self::query(client).boxed()
     }

src/interactors/github.rs

@@ -1,17 +1,11 @@
-use std::{
+use std::fmt;
-    fmt,
-    task::{Context, Poll},
-};
 
+use actix_web::dev::Service;
 use anyhow::Error;
-use futures_util::FutureExt as _;
+use futures_util::{future::LocalBoxFuture, FutureExt as _};
-use hyper::service::Service;
 use serde::Deserialize;
 
-use crate::{
+use crate::models::repo::{RepoPath, Repository};
-    models::repo::{RepoPath, Repository},
-    BoxFuture,
-};
 
 const GITHUB_API_BASE_URI: &str = "https://api.github.com";
 
@@ -72,13 +66,11 @@ impl fmt::Debug for GetPopularRepos {
 impl Service<()> for GetPopularRepos {
     type Response = Vec<Repository>;
     type Error = Error;
-    type Future = BoxFuture<Result<Self::Response, Self::Error>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    actix_web::dev::always_ready!();
-        Poll::Ready(Ok(()))
-    }
 
-    fn call(&mut self, _req: ()) -> Self::Future {
+    fn call(&self, _req: ()) -> Self::Future {
         let client = self.client.clone();
         Self::query(client).boxed()
     }

src/interactors/mod.rs

@@ -1,14 +1,11 @@
-use std::{
+use std::fmt;
-    fmt,
-    task::{Context, Poll},
-};
 
+use actix_web::dev::Service;
 use anyhow::{anyhow, Error};
-use futures_util::FutureExt as _;
+use futures_util::{future::LocalBoxFuture, FutureExt as _};
-use hyper::service::Service;
 use relative_path::RelativePathBuf;
 
-use crate::{models::repo::RepoPath, BoxFuture};
+use crate::models::repo::RepoPath;
 
 pub mod crates;
 pub mod github;
@@ -43,13 +40,11 @@ impl RetrieveFileAtPath {
 impl Service<(RepoPath, RelativePathBuf)> for RetrieveFileAtPath {
     type Response = String;
     type Error = Error;
-    type Future = BoxFuture<Result<Self::Response, Self::Error>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    actix_web::dev::always_ready!();
-        Poll::Ready(Ok(()))
-    }
 
-    fn call(&mut self, (repo_path, path): (RepoPath, RelativePathBuf)) -> Self::Future {
+    fn call(&self, (repo_path, path): (RepoPath, RelativePathBuf)) -> Self::Future {
         let client = self.client.clone();
         Self::query(client, repo_path, path).boxed()
     }

src/interactors/rustsec.rs

@@ -1,16 +1,10 @@
-use std::{
+use std::{fmt, sync::Arc};
-    fmt,
-    sync::Arc,
-    task::{Context, Poll},
-};
 
+use actix_web::dev::Service;
 use anyhow::Error;
-use futures_util::FutureExt as _;
+use futures_util::{future::LocalBoxFuture, FutureExt as _};
-use hyper::service::Service;
 use rustsec::database::Database;
 
-use crate::BoxFuture;
-
 #[derive(Clone)]
 pub struct FetchAdvisoryDatabase {
     client: reqwest::Client,
@@ -30,20 +24,19 @@ impl FetchAdvisoryDatabase {
 impl Service<()> for FetchAdvisoryDatabase {
     type Response = Arc<Database>;
     type Error = Error;
-    type Future = BoxFuture<Result<Self::Response, Self::Error>>;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
 
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+    actix_web::dev::always_ready!();
-        Poll::Ready(Ok(()))
-    }
 
-    fn call(&mut self, _req: ()) -> Self::Future {
+    fn call(&self, _req: ()) -> Self::Future {
         let client = self.client.clone();
-        Self::fetch(client).boxed()
+        Self::fetch(client).boxed_local()
     }
 }
 
 impl fmt::Debug for FetchAdvisoryDatabase {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str("FetchAdvisoryDatabase")
+        f.debug_struct("FetchAdvisoryDatabase")
+            .finish_non_exhaustive()
     }
 }

src/main.rs

@@ -3,20 +3,14 @@
 
 use std::{
     env,
-    future::Future,
+    net::{Ipv4Addr, UdpSocket},
-    net::{IpAddr, Ipv4Addr, SocketAddr, UdpSocket},
-    pin::Pin,
     time::Duration,
 };
 
+use actix_web::{middleware::Logger, web};
+use actix_web_lab::{extract::ThinData, middleware::NormalizePath};
 use cadence::{QueuingMetricSink, UdpMetricSink};
-use hyper::{
-    server::conn::AddrStream,
-    service::{make_service_fn, service_fn},
-    Server,
-};
 use reqwest::redirect::Policy as RedirectPolicy;
-use tracing::Instrument as _;
 
 mod engine;
 mod interactors;
@@ -25,10 +19,7 @@ mod parsers;
 mod server;
 mod utils;
 
-use self::{engine::Engine, server::App, utils::index::ManagedIndex};
+use self::{engine::Engine, utils::index::ManagedIndex};
-
-/// Future crate's BoxFuture without the explicit lifetime parameter.
-pub type BoxFuture<T> = Pin<Box<dyn Future<Output = T> + Send>>;
 
 const DEPS_RS_UA: &str = "deps.rs";
 
@@ -59,7 +50,7 @@ fn init_tracing_subscriber() {
         .init();
 }
 
-#[tokio::main]
+#[tokio::main(flavor = "current_thread")]
 async fn main() {
     dotenvy::dotenv().ok();
     init_tracing_subscriber();
@@ -77,8 +68,6 @@ async fn main() {
         .parse()
         .expect("could not read port");
 
-    let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), port);
-
     let index = ManagedIndex::new();
 
     {
@@ -92,25 +81,24 @@ async fn main() {
     let mut engine = Engine::new(client.clone(), index);
     engine.set_metrics(metrics);
 
-    let make_svc = make_service_fn(move |_socket: &AddrStream| {
+    let server = actix_web::HttpServer::new(move || {
-        let engine = engine.clone();
+        actix_web::App::new()
-
+            .app_data(ThinData(engine.clone()))
-        async move {
+            .service(server::index)
-            let server = App::new(engine.clone());
+            .service(server::crate_redirect)
-            Ok::<_, hyper::Error>(service_fn(move |req| {
+            .service(server::crate_latest_status_svg)
-                let server = server.clone();
+            .service(server::crate_status_svg)
-                async move {
+            .service(server::crate_status_html)
-                    let path = req.uri().path().to_owned();
+            .service(server::repo_status_svg)
-
+            .service(server::repo_status_html)
-                    server
+            .configure(server::static_files)
-                        .handle(req)
+            .default_service(web::to(server::not_found))
-                        .instrument(tracing::info_span!("@", %path))
+            .wrap(NormalizePath::trim())
-                        .await
+            .wrap(Logger::default())
-                }
+    })
-            }))
+    .bind_auto_h2c((Ipv4Addr::UNSPECIFIED, port))
-        }
+    .unwrap()
-    });
+    .run();
-    let server = Server::bind(&addr).serve(make_svc);
 
     tracing::info!("Server running on port {port}");
 

src/models/repo.rs

@@ -100,7 +100,7 @@ impl FromStr for RepoSite {
         if let Some((site, domain)) = input.split_once('/') {
             match site {
                 "gitea" => Ok(RepoSite::Gitea(domain.parse()?)),
-                _ => Err(anyhow!("unknown repo site identifier")),
+                site => Err(anyhow!("unknown repo site identifier: {site}")),
             }
         } else {
             match input {
@@ -109,7 +109,7 @@ impl FromStr for RepoSite {
                 "bitbucket" => Ok(RepoSite::Bitbucket),
                 "sourcehut" => Ok(RepoSite::Sourcehut),
                 "codeberg" => Ok(RepoSite::Codeberg),
-                _ => Err(anyhow!("unknown repo site identifier")),
+                site => Err(anyhow!("unknown repo site identifier: {site}")),
             }
         }
     }

src/server/assets.rs

@@ -4,11 +4,9 @@ pub const STATIC_STYLE_CSS_PATH: &str = concat!(
     include_str!(concat!(env!("OUT_DIR"), "/style.css.sha1")),
     ".css"
 );
-pub const STATIC_STYLE_CSS_ETAG: &str = concat!(
+pub const STATIC_STYLE_CSS_ETAG: &str = include_str!(concat!(env!("OUT_DIR"), "/style.css.sha1"));
-    "\"",
+
-    include_str!(concat!(env!("OUT_DIR"), "/style.css.sha1")),
+pub const STATIC_FAVICON_PATH: &str = "/static/logo.svg";
-    "\""
-);
 pub static STATIC_FAVICON: &[u8] = include_bytes!("../../assets/logo.svg");
 
 pub static STATIC_LINKS_JS: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/links.js"));
@@ -17,8 +15,4 @@ pub const STATIC_LINKS_JS_PATH: &str = concat!(
     include_str!(concat!(env!("OUT_DIR"), "/links.js.sha1")),
     ".js"
 );
-pub const STATIC_LINKS_JS_ETAG: &str = concat!(
+pub const STATIC_LINKS_JS_ETAG: &str = include_str!(concat!(env!("OUT_DIR"), "/links.js.sha1"));
-    "\"",
-    include_str!(concat!(env!("OUT_DIR"), "/links.js.sha1")),
-    "\""
-);

src/server/error.rs

@@ -0,0 +1,79 @@
+use actix_web::{
+    http::{header::ContentType, StatusCode},
+    HttpResponse, ResponseError,
+};
+use derive_more::Display;
+use maud::Markup;
+
+use crate::server::views::html::error::{render, render_404};
+
+#[derive(Debug, Display)]
+pub(crate) enum ServerError {
+    #[display("Could not retrieve popular items")]
+    PopularItemsFailed,
+
+    #[display("Crate not found")]
+    CrateNotFound,
+
+    #[display("Could not parse crate path")]
+    BadCratePath,
+
+    #[display("Could not fetch crate information")]
+    CrateFetchFailed,
+
+    #[display("Could not parse repository path")]
+    BadRepoPath,
+
+    #[display("Crate/repo analysis failed")]
+    AnalysisFailed(Markup),
+}
+
+impl ResponseError for ServerError {
+    fn status_code(&self) -> StatusCode {
+        match self {
+            ServerError::PopularItemsFailed => StatusCode::INTERNAL_SERVER_ERROR,
+            ServerError::CrateNotFound => StatusCode::NOT_FOUND,
+            ServerError::BadCratePath => StatusCode::BAD_REQUEST,
+            ServerError::CrateFetchFailed => StatusCode::NOT_FOUND,
+            ServerError::BadRepoPath => StatusCode::BAD_REQUEST,
+            ServerError::AnalysisFailed(_) => StatusCode::BAD_REQUEST,
+        }
+    }
+
+    fn error_response(&self) -> HttpResponse {
+        let mut res = HttpResponse::build(self.status_code());
+        let res = res.insert_header(ContentType::html());
+
+        match self {
+            ServerError::PopularItemsFailed => res.body(render(self.to_string(), "").0),
+
+            ServerError::CrateNotFound => res.body(render_404().0),
+
+            ServerError::BadCratePath => res.body(
+                render(
+                    self.to_string(),
+                    "Please make sure to provide a valid crate name and version.",
+                )
+                .0,
+            ),
+
+            ServerError::CrateFetchFailed => res.body(
+                render(
+                    self.to_string(),
+                    "Please make sure to provide a valid crate name.",
+                )
+                .0,
+            ),
+
+            ServerError::BadRepoPath => res.body(
+                render(
+                    self.to_string(),
+                    "Please make sure to provide a valid repository path.",
+                )
+                .0,
+            ),
+
+            Self::AnalysisFailed(html) => res.body(html.0.clone()),
+        }
+    }
+}

src/server/mod.rs

@@ -1,21 +1,35 @@
-use std::{env, sync::Arc, time::Instant};
+use std::env;
 
+use actix_web::{
+    get,
+    http::{
+        header::{ContentType, ETag, EntityTag},
+        Uri,
+    },
+    web::{Redirect, ServiceConfig},
+    Either, HttpResponse, Resource, Responder,
+};
+use actix_web_lab::{
+    extract::{Path, ThinData},
+    header::{CacheControl, CacheDirective},
+    respond::Html,
+};
+use assets::STATIC_FAVICON_PATH;
 use badge::BadgeStyle;
 use futures_util::future;
-use hyper::{
-    header::{CACHE_CONTROL, CONTENT_TYPE, ETAG, LOCATION},
-    Body, Error as HyperError, Method, Request, Response, StatusCode,
-};
 use once_cell::sync::Lazy;
-use route_recognizer::{Params, Router};
 use semver::VersionReq;
 use serde::Deserialize;
 
 mod assets;
+mod error;
 mod views;
 
-use self::assets::{
+use self::{
+    assets::{
         STATIC_LINKS_JS_ETAG, STATIC_LINKS_JS_PATH, STATIC_STYLE_CSS_ETAG, STATIC_STYLE_CSS_PATH,
+    },
+    error::ServerError,
 };
 use crate::{
     engine::{AnalyzeDependenciesOutcome, Engine},
@@ -24,252 +38,120 @@ use crate::{
         repo::RepoPath,
         SubjectPath,
     },
+    utils::common::{safe_truncate, UntaggedEither, WrappedBool},
 };
 
+const MAX_SUBJECT_WIDTH: usize = 100;
+
 #[derive(Debug, Clone, Copy, PartialEq)]
 enum StatusFormat {
     Html,
     Svg,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[get("/")]
-enum StaticFile {
+pub(crate) async fn index(ThinData(engine): ThinData<Engine>) -> actix_web::Result<impl Responder> {
-    StyleCss,
+    let popular = future::try_join(engine.get_popular_repos(), engine.get_popular_crates()).await;
-    FaviconPng,
-    LinksJs,
-}
-
-enum Route {
-    Index,
-    Static(StaticFile),
-    RepoStatus(StatusFormat),
-    CrateRedirect,
-    CrateStatus(StatusFormat),
-    LatestCrateBadge,
-}
-
-#[derive(Clone)]
-pub struct App {
-    engine: Engine,
-    router: Arc<Router<Route>>,
-}
-
-impl App {
-    pub fn new(engine: Engine) -> App {
-        let mut router = Router::new();
-
-        router.add("/", Route::Index);
-
-        router.add(STATIC_STYLE_CSS_PATH, Route::Static(StaticFile::StyleCss));
-        router.add("/static/logo.svg", Route::Static(StaticFile::FaviconPng));
-        router.add(STATIC_LINKS_JS_PATH, Route::Static(StaticFile::LinksJs));
-
-        router.add(
-            "/repo/*site/:qual/:name",
-            Route::RepoStatus(StatusFormat::Html),
-        );
-        router.add(
-            "/repo/*site/:qual/:name/status.svg",
-            Route::RepoStatus(StatusFormat::Svg),
-        );
-
-        router.add("/crate/:name", Route::CrateRedirect);
-        router.add(
-            "/crate/:name/:version",
-            Route::CrateStatus(StatusFormat::Html),
-        );
-        router.add("/crate/:name/latest/status.svg", Route::LatestCrateBadge);
-        router.add(
-            "/crate/:name/:version/status.svg",
-            Route::CrateStatus(StatusFormat::Svg),
-        );
-
-        App {
-            engine,
-            router: Arc::new(router),
-        }
-    }
-
-    pub async fn handle(&self, req: Request<Body>) -> Result<Response<Body>, HyperError> {
-        let start = Instant::now();
-
-        // allows `/path/` to also match `/path`
-        let normalized_path = req.uri().path().trim_end_matches('/');
-
-        let res = if let Ok(route_match) = self.router.recognize(normalized_path) {
-            match (req.method(), route_match.handler()) {
-                (&Method::GET, Route::Index) => self.index(req, route_match.params().clone()).await,
-
-                (&Method::GET, Route::RepoStatus(format)) => {
-                    self.repo_status(req, route_match.params().clone(), *format)
-                        .await
-                }
-
-                (&Method::GET, Route::CrateStatus(format)) => {
-                    self.crate_status(req, route_match.params().clone(), *format)
-                        .await
-                }
-
-                (&Method::GET, Route::LatestCrateBadge) => {
-                    self.crate_status(req, route_match.params().clone(), StatusFormat::Svg)
-                        .await
-                }
-
-                (&Method::GET, Route::CrateRedirect) => {
-                    self.crate_redirect(req, route_match.params().clone()).await
-                }
-
-                (&Method::GET, Route::Static(file)) => Ok(App::static_file(*file)),
-
-                _ => Ok(not_found()),
-            }
-        } else {
-            Ok(not_found())
-        };
-
-        let end = Instant::now();
-        let diff = end - start;
-
-        match &res {
-            Ok(res) => tracing::info!(
-                status = %res.status(),
-                time = %format_args!("{}ms", diff.as_millis()),
-            ),
-            Err(err) => tracing::error!(%err),
-        };
-
-        res
-    }
-}
-
-impl App {
-    async fn index(
-        &self,
-        _req: Request<Body>,
-        _params: Params,
-    ) -> Result<Response<Body>, HyperError> {
-        let engine = self.engine.clone();
-
-        let popular =
-            future::try_join(engine.get_popular_repos(), engine.get_popular_crates()).await;
 
     match popular {
         Err(err) => {
             tracing::error!(%err);
-                let mut response =
+            Err(ServerError::PopularItemsFailed.into())
-                    views::html::error::render("Could not retrieve popular items", "");
-                *response.status_mut() = StatusCode::INTERNAL_SERVER_ERROR;
-                Ok(response)
         }
-            Ok((popular_repos, popular_crates)) => {
+        Ok((popular_repos, popular_crates)) => Ok(Html::new(
-                Ok(views::html::index::render(popular_repos, popular_crates))
+            views::html::index::render(popular_repos, popular_crates).0,
+        )),
     }
 }
+
+#[get("/repo/{site:.+?}/{qual}/{name}/status.svg")]
+pub(crate) async fn repo_status_svg(
+    ThinData(engine): ThinData<Engine>,
+    uri: Uri,
+    Path(params): Path<(String, String, String)>,
+) -> actix_web::Result<impl Responder> {
+    repo_status(engine, uri, params, StatusFormat::Svg).await
+}
+
+#[get("/repo/{site:.+?}/{qual}/{name}")]
+pub(crate) async fn repo_status_html(
+    ThinData(engine): ThinData<Engine>,
+    uri: Uri,
+    Path(params): Path<(String, String, String)>,
+) -> actix_web::Result<impl Responder> {
+    repo_status(engine, uri, params, StatusFormat::Html).await
 }
 
 async fn repo_status(
-        &self,
+    engine: Engine,
-        req: Request<Body>,
+    uri: Uri,
-        params: Params,
+    (site, qual, name): (String, String, String),
     format: StatusFormat,
-    ) -> Result<Response<Body>, HyperError> {
+) -> actix_web::Result<impl Responder> {
-        let server = self.clone();
+    let extra_knobs = ExtraConfig::from_query_string(uri.query());
 
-        let site = params.find("site").expect("route param 'site' not found");
+    let repo_path_result = RepoPath::from_parts(&site, &qual, &name);
-        let qual = params.find("qual").expect("route param 'qual' not found");
-        let name = params.find("name").expect("route param 'name' not found");
 
-        let extra_knobs = ExtraConfig::from_query_string(req.uri().query());
+    let repo_path = match repo_path_result {
-
+        Ok(repo_path) => repo_path,
-        let repo_path_result = RepoPath::from_parts(site, qual, name);
-
-        match repo_path_result {
         Err(err) => {
             tracing::error!(%err);
-                let mut response = views::html::error::render(
+            return Err(ServerError::BadRepoPath.into());
-                    "Could not parse repository path",
-                    "Please make sure to provide a valid repository path.",
-                );
-                *response.status_mut() = StatusCode::BAD_REQUEST;
-                Ok(response)
         }
+    };
 
-            Ok(repo_path) => {
+    let analyze_result = engine
-                let analyze_result = server
-                    .engine
         .analyze_repo_dependencies(repo_path.clone(), &extra_knobs.path)
         .await;
 
     match analyze_result {
         Err(err) => {
             tracing::error!(%err);
-                        let response = App::status_format_analysis(
+            let response =
-                            None,
+                status_format_analysis(None, format, SubjectPath::Repo(repo_path), extra_knobs);
-                            format,
+
-                            SubjectPath::Repo(repo_path),
-                            extra_knobs,
-                        );
             Ok(response)
         }
+
         Ok(analysis_outcome) => {
-                        let response = App::status_format_analysis(
+            let response = status_format_analysis(
                 Some(analysis_outcome),
                 format,
                 SubjectPath::Repo(repo_path),
                 extra_knobs,
             );
+
             Ok(response)
         }
     }
 }
-        }
-    }
 
+#[get("/crate/:name")]
 async fn crate_redirect(
-        &self,
+    ThinData(engine): ThinData<Engine>,
-        _req: Request<Body>,
+    Path((name,)): Path<(String,)>,
-        params: Params,
+) -> actix_web::Result<impl Responder> {
-    ) -> Result<Response<Body>, HyperError> {
-        let engine = self.engine.clone();
-
-        let name = params.find("name").expect("route param 'name' not found");
     let crate_name_result = name.parse::<CrateName>();
 
-        match crate_name_result {
+    let crate_name = match crate_name_result {
+        Ok(crate_name) => crate_name,
         Err(err) => {
             tracing::error!(%err);
-                let mut response = views::html::error::render(
+            return Err(ServerError::BadCratePath.into());
-                    "Could not parse crate name",
-                    "Please make sure to provide a valid crate name.",
-                );
-                *response.status_mut() = StatusCode::BAD_REQUEST;
-                Ok(response)
         }
+    };
 
-            Ok(crate_name) => {
     let release_result = engine
         .find_latest_stable_crate_release(crate_name, VersionReq::STAR)
-                    .await;
+        .await
-
+        .inspect_err(|err| {
-                match release_result {
-                    Err(err) => {
             tracing::error!(%err);
-                        let mut response = views::html::error::render(
+        });
-                            "Could not fetch crate information",
+
-                            "Please make sure to provide a valid crate name.",
+    let Ok(Some(release)) = release_result else {
-                        );
+        return Err(ServerError::CrateFetchFailed.into());
-                        *response.status_mut() = StatusCode::NOT_FOUND;
+    };
-                        Ok(response)
+
-                    }
-                    Ok(None) => {
-                        let mut response = views::html::error::render(
-                            "Could not fetch crate information",
-                            "Please make sure to provide a valid crate name.",
-                        );
-                        *response.status_mut() = StatusCode::NOT_FOUND;
-                        Ok(response)
-                    }
-                    Ok(Some(release)) => {
     let redirect_url = format!(
         "{}/crate/{}/{}",
         &SELF_BASE_URL as &str,
@@ -277,97 +159,86 @@ impl App {
         release.version
     );
 
-                        let res = Response::builder()
+    Ok(Redirect::to(redirect_url))
-                            .status(StatusCode::TEMPORARY_REDIRECT)
+}
-                            .header(LOCATION, redirect_url)
-                            .body(Body::empty())
-                            .unwrap();
 
-                        Ok(res)
+#[get("/crate/{name}/{version}")]
-                    }
+async fn crate_status_html(
-                }
+    ThinData(engine): ThinData<Engine>,
+    uri: Uri,
+    Path((name, version)): Path<(String, String)>,
+) -> actix_web::Result<impl Responder> {
+    crate_status(engine, uri, (name, Some(version)), StatusFormat::Html).await
 }
+
+#[get("/crate/{name}/latest/status.svg")]
+async fn crate_latest_status_svg(
+    ThinData(engine): ThinData<Engine>,
+    uri: Uri,
+    Path((name,)): Path<(String,)>,
+) -> actix_web::Result<impl Responder> {
+    crate_status(engine, uri, (name, None), StatusFormat::Svg).await
 }
+
+#[get("/crate/{name}/{version}/status.svg")]
+async fn crate_status_svg(
+    ThinData(engine): ThinData<Engine>,
+    uri: Uri,
+    Path((name, version)): Path<(String, String)>,
+) -> actix_web::Result<impl Responder> {
+    crate_status(engine, uri, (name, Some(version)), StatusFormat::Svg).await
 }
 
 async fn crate_status(
-        &self,
+    engine: Engine,
-        req: Request<Body>,
+    uri: Uri,
-        params: Params,
+    (name, version): (String, Option<String>),
     format: StatusFormat,
-    ) -> Result<Response<Body>, HyperError> {
+) -> actix_web::Result<impl Responder> {
-        let server = self.clone();
+    let version = match version {
-
-        let name = params.find("name").expect("route param 'name' not found");
-
-        let version = match params.find("version") {
         Some(ver) => ver.to_owned(),
         None => {
             let crate_name = match name.parse() {
                 Ok(name) => name,
-                    Err(_) => {
+                Err(_) => return Err(ServerError::BadCratePath.into()),
-                        let mut response = views::html::error::render(
-                            "Could not parse crate path",
-                            "Please make sure to provide a valid crate name and version.",
-                        );
-                        *response.status_mut() = StatusCode::BAD_REQUEST;
-                        return Ok(response);
-                    }
             };
 
-                match server
+            match engine
-                    .engine
                 .find_latest_stable_crate_release(crate_name, VersionReq::STAR)
                 .await
             {
                 Ok(Some(latest_rel)) => latest_rel.version.to_string(),
-                    Ok(None) => return Ok(not_found()),
+
+                Ok(None) => return Err(ServerError::CrateNotFound.into()),
+
                 Err(err) => {
                     tracing::error!(%err);
-                        let mut response = views::html::error::render(
+                    return Err(ServerError::CrateFetchFailed.into());
-                            "Could not fetch crate information",
-                            "Please make sure to provide a valid crate name.",
-                        );
-                        *response.status_mut() = StatusCode::NOT_FOUND;
-                        return Ok(response);
                 }
             }
         }
     };
 
-        let crate_path_result = CratePath::from_parts(name, &version);
+    let crate_path_result = CratePath::from_parts(&name, &version);
-        let badge_knobs = ExtraConfig::from_query_string(req.uri().query());
+    let badge_knobs = ExtraConfig::from_query_string(uri.query());
 
     match crate_path_result {
         Err(err) => {
             tracing::error!(%err);
-                let mut response = views::html::error::render(
+            Err(ServerError::BadCratePath.into())
-                    "Could not parse crate path",
-                    "Please make sure to provide a valid crate name and version.",
-                );
-                *response.status_mut() = StatusCode::BAD_REQUEST;
-                Ok(response)
         }
+
         Ok(crate_path) => {
-                let analyze_result = server
+            let analysis_outcome = engine
-                    .engine
                 .analyze_crate_dependencies(crate_path.clone())
-                    .await;
+                .await
-
+                .inspect_err(|err| {
-                match analyze_result {
-                    Err(err) => {
                     tracing::error!(%err);
-                        let response = App::status_format_analysis(
+                })
-                            None,
+                .ok();
-                            format,
+
-                            SubjectPath::Crate(crate_path),
+            let response = status_format_analysis(
-                            badge_knobs,
+                analysis_outcome,
-                        );
-                        Ok(response)
-                    }
-                    Ok(analysis_outcome) => {
-                        let response = App::status_format_analysis(
-                            Some(analysis_outcome),
                 format,
                 SubjectPath::Crate(crate_path),
                 badge_knobs,
@@ -377,47 +248,61 @@ impl App {
         }
     }
 }
-        }
-    }
 
 fn status_format_analysis(
     analysis_outcome: Option<AnalyzeDependenciesOutcome>,
     format: StatusFormat,
     subject_path: SubjectPath,
     badge_knobs: ExtraConfig,
-    ) -> Response<Body> {
+) -> impl Responder {
     match format {
-            StatusFormat::Svg => views::badge::response(analysis_outcome.as_ref(), badge_knobs),
+        StatusFormat::Svg => Either::Left(views::badge::response(
-            StatusFormat::Html => {
+            analysis_outcome.as_ref(),
-                views::html::status::render(analysis_outcome, subject_path, badge_knobs)
+            badge_knobs,
-            }
+        )),
+
+        StatusFormat::Html => Either::Right(views::html::status::response(
+            analysis_outcome,
+            subject_path,
+            badge_knobs,
+        )),
     }
 }
 
-    fn static_file(file: StaticFile) -> Response<Body> {
+pub(crate) fn static_files(cfg: &mut ServiceConfig) {
-        match file {
+    cfg.service(Resource::new(STATIC_STYLE_CSS_PATH).get(|| async {
-            StaticFile::StyleCss => Response::builder()
+        HttpResponse::Ok()
-                .header(CONTENT_TYPE, "text/css; charset=utf-8")
+            .insert_header(ContentType(mime::TEXT_CSS_UTF_8))
-                .header(ETAG, STATIC_STYLE_CSS_ETAG)
+            .insert_header(ETag(EntityTag::new_strong(
-                .header(CACHE_CONTROL, "public, max-age=365000000, immutable")
+                STATIC_STYLE_CSS_ETAG.to_owned(),
-                .body(Body::from(assets::STATIC_STYLE_CSS))
+            )))
-                .unwrap(),
+            .insert_header(CacheControl(vec![
-            StaticFile::FaviconPng => Response::builder()
+                CacheDirective::Public,
-                .header(CONTENT_TYPE, "image/svg+xml")
+                CacheDirective::MaxAge(365000000),
-                .body(Body::from(assets::STATIC_FAVICON))
+                CacheDirective::Immutable,
-                .unwrap(),
+            ]))
-            StaticFile::LinksJs => Response::builder()
+            .body(assets::STATIC_STYLE_CSS)
-                .header(CONTENT_TYPE, "text/javascript; charset=utf-8")
+    }))
-                .header(ETAG, STATIC_LINKS_JS_ETAG)
+    .service(Resource::new(STATIC_FAVICON_PATH).get(|| async {
-                .header(CACHE_CONTROL, "public, max-age=365000000, immutable")
+        HttpResponse::Ok()
-                .body(Body::from(assets::STATIC_LINKS_JS))
+            .insert_header(ContentType(mime::IMAGE_SVG))
-                .unwrap(),
+            .body(assets::STATIC_FAVICON)
-        }
+    }))
-    }
+    .service(Resource::new(STATIC_LINKS_JS_PATH).get(|| async {
+        HttpResponse::Ok()
+            .insert_header(ContentType(mime::APPLICATION_JAVASCRIPT_UTF_8))
+            .insert_header(ETag(EntityTag::new_strong(STATIC_LINKS_JS_ETAG.to_owned())))
+            .insert_header(CacheControl(vec![
+                CacheDirective::Public,
+                CacheDirective::MaxAge(365000000),
+                CacheDirective::Immutable,
+            ]))
+            .body(assets::STATIC_LINKS_JS)
+    }));
 }
 
-fn not_found() -> Response<Body> {
+pub(crate) async fn not_found() -> impl Responder {
-    views::html::error::render_404()
+    Html::new(views::html::error::render_404().0)
 }
 
 static SELF_BASE_URL: Lazy<String> =
@@ -428,18 +313,35 @@ static SELF_BASE_URL: Lazy<String> =
 pub struct ExtraConfig {
     /// Badge style to show
     style: BadgeStyle,
+
     /// Whether the inscription _"dependencies"_ should be abbreviated as _"deps"_ in the badge.
     compact: bool,
+
+    /// Custom text on the left (it's the same concept as `label` in shields.io).
+    subject: Option<String>,
+
     /// Path in which the crate resides within the repository
     path: Option<String>,
 }
 
 impl ExtraConfig {
     fn from_query_string(qs: Option<&str>) -> Self {
+        /// This wrapper can make the deserialization process infallible.
+        #[derive(Debug, Clone, Deserialize)]
+        #[serde(transparent)]
+        struct QueryParam<T>(UntaggedEither<T, String>);
+
+        impl<T> QueryParam<T> {
+            fn opt(self) -> Option<T> {
+                either::Either::from(self.0).left()
+            }
+        }
+
         #[derive(Debug, Clone, Default, Deserialize)]
         struct ExtraConfigPartial {
-            style: Option<BadgeStyle>,
+            style: Option<QueryParam<BadgeStyle>>,
-            compact: Option<bool>,
+            compact: Option<QueryParam<WrappedBool>>,
+            subject: Option<String>,
             path: Option<String>,
         }
 
@@ -448,9 +350,33 @@ impl ExtraConfig {
             .unwrap_or_default();
 
         Self {
-            style: extra_config.style.unwrap_or_default(),
+            style: extra_config
-            compact: extra_config.compact.unwrap_or_default(),
+                .style
+                .and_then(|qp| qp.opt())
+                .unwrap_or_default(),
+            compact: extra_config
+                .compact
+                .and_then(|qp| qp.opt())
+                .unwrap_or_default()
+                .0,
+            subject: extra_config
+                .subject
+                .filter(|t| !t.is_empty())
+                .map(|subject| safe_truncate(&subject, MAX_SUBJECT_WIDTH).to_owned()),
             path: extra_config.path,
         }
     }
+
+    /// Returns subject for badge.
+    ///
+    /// Returns `subject` if set, or "dependencies" / "deps" depending on value of `compact`.
+    pub(crate) fn subject(&self) -> &str {
+        if let Some(subject) = &self.subject {
+            subject
+        } else if self.compact {
+            "deps"
+        } else {
+            "dependencies"
+        }
+    }
 }

src/server/views/badge.rs

@@ -1,5 +1,5 @@
+use actix_web::{http::header::ContentType, HttpResponse};
 use badge::{Badge, BadgeOptions};
-use hyper::{header::CONTENT_TYPE, Body, Response};
 
 use crate::{engine::AnalyzeDependenciesOutcome, server::ExtraConfig};
 
@@ -7,12 +7,7 @@ pub fn badge(
     analysis_outcome: Option<&AnalyzeDependenciesOutcome>,
     badge_knobs: ExtraConfig,
 ) -> Badge {
-    let subject = if badge_knobs.compact {
+    let subject = badge_knobs.subject().to_owned();
-        "deps"
-    } else {
-        "dependencies"
-    }
-    .to_owned();
 
     let opts = match analysis_outcome {
         Some(outcome) => {
@@ -73,11 +68,10 @@ pub fn badge(
 pub fn response(
     analysis_outcome: Option<&AnalyzeDependenciesOutcome>,
     badge_knobs: ExtraConfig,
-) -> Response<Body> {
+) -> HttpResponse {
     let badge = badge(analysis_outcome, badge_knobs).to_svg();
 
-    Response::builder()
+    HttpResponse::Ok()
-        .header(CONTENT_TYPE, "image/svg+xml; charset=utf-8")
+        .insert_header(ContentType(mime::IMAGE_SVG))
-        .body(Body::from(badge))
+        .body(badge)
-        .unwrap()
 }

src/server/views/html/error.rs

@@ -1,14 +1,12 @@
-use hyper::{
+use maud::{html, Markup};
-    header::{CACHE_CONTROL, CONTENT_TYPE},
-    Body, Response, StatusCode,
-};
-use maud::html;
 
 use crate::server::assets::STATIC_STYLE_CSS_PATH;
 
-pub fn render(title: &str, descr: &str) -> Response<Body> {
+pub fn render(title: impl Into<String>, desc: &str) -> Markup {
+    let title = title.into();
+
     super::render_html(
-        title,
+        title.clone(),
         html! {
             section class="hero is-light" {
                 div class="hero-head" { (super::render_navbar()) }
@@ -17,7 +15,7 @@ pub fn render(title: &str, descr: &str) -> Response<Body> {
                 div class="container" {
                     div class="notification is-danger" {
                         p class="title is-3" { (title) }
-                        p { (descr) }
+                        p { (desc) }
                     }
                 }
             }
@@ -26,8 +24,8 @@ pub fn render(title: &str, descr: &str) -> Response<Body> {
     )
 }
 
-pub fn render_404() -> Response<Body> {
+pub fn render_404() -> Markup {
-    let rendered = html! {
+    html! {
         html {
             head {
                 meta charset="utf-8";
@@ -53,12 +51,5 @@ pub fn render_404() -> Response<Body> {
                 (super::render_footer(None))
             }
         }
-    };
+    }
-
-    Response::builder()
-        .status(StatusCode::NOT_FOUND)
-        .header(CONTENT_TYPE, "text/html; charset=utf-8")
-        .header(CACHE_CONTROL, "public, max-age=300, immutable")
-        .body(Body::from(rendered.0))
-        .unwrap()
 }

src/server/views/html/index.rs

@@ -1,4 +1,3 @@
-use hyper::{Body, Response};
 use maud::{html, Markup};
 
 use crate::{
@@ -161,7 +160,7 @@ fn popular_table(popular_repos: Vec<Repository>, popular_crates: Vec<CratePath>)
     }
 }
 
-pub fn render(popular_repos: Vec<Repository>, popular_crates: Vec<CratePath>) -> Response<Body> {
+pub fn render(popular_repos: Vec<Repository>, popular_crates: Vec<CratePath>) -> Markup {
     super::render_html(
         "Keep your dependencies up-to-date",
         html! {

src/server/views/html/mod.rs

@@ -1,6 +1,5 @@
 use std::time::Duration;
 
-use hyper::{header::CONTENT_TYPE, Body, Response};
 use maud::{html, Markup, Render, DOCTYPE};
 
 pub mod error;
@@ -9,8 +8,10 @@ pub mod status;
 
 use crate::server::{assets::STATIC_STYLE_CSS_PATH, SELF_BASE_URL};
 
-fn render_html<B: Render>(title: &str, body: B) -> Response<Body> {
+fn render_html<B: Render>(title: impl Into<String>, body: B) -> Markup {
-    let rendered = html! {
+    let title = title.into();
+
+    html! {
         (DOCTYPE)
         html {
             head {
@@ -24,12 +25,7 @@ fn render_html<B: Render>(title: &str, body: B) -> Response<Body> {
             }
             body { (body) }
         }
-    };
+    }
-
-    Response::builder()
-        .header(CONTENT_TYPE, "text/html; charset=utf-8")
-        .body(Body::from(rendered.0))
-        .unwrap()
 }
 
 fn render_navbar() -> Markup {

src/server/views/html/status.rs

@@ -1,5 +1,6 @@
+use actix_web::Responder;
+use actix_web_lab::respond::Html;
 use font_awesome_as_a_crate::{svg as fa, Type as FaType};
-use hyper::{Body, Response};
 use indexmap::IndexMap;
 use maud::{html, Markup, PreEscaped};
 use pulldown_cmark::{html, Parser};
@@ -13,9 +14,11 @@ use crate::{
         repo::RepoSite,
         SubjectPath,
     },
-    server::{views::badge, ExtraConfig},
+    server::{error::ServerError, views::badge, ExtraConfig},
 };
 
+use super::render_html;
+
 fn get_crates_url(name: impl AsRef<str>) -> String {
     format!("https://crates.io/crates/{}", name.as_ref())
 }
@@ -453,11 +456,11 @@ fn render_success(
     }
 }
 
-pub fn render(
+pub fn response(
     analysis_outcome: Option<AnalyzeDependenciesOutcome>,
     subject_path: SubjectPath,
     extra_config: ExtraConfig,
-) -> Response<Body> {
+) -> actix_web::Result<impl Responder> {
     let title = match subject_path {
         SubjectPath::Repo(ref repo_path) => {
             format!("{} / {}", repo_path.qual.as_ref(), repo_path.name.as_ref())
@@ -468,8 +471,12 @@ pub fn render(
     };
 
     if let Some(outcome) = analysis_outcome {
-        super::render_html(&title, render_success(outcome, subject_path, extra_config))
+        Ok(Html::new(render_html(
+            &title,
+            render_success(outcome, subject_path, extra_config),
+        )))
     } else {
-        super::render_html(&title, render_failure(subject_path))
+        let html = render_html(&title, render_failure(subject_path));
+        Err(ServerError::AnalysisFailed(html).into())
     }
 }

src/utils/cache.rs

@@ -1,7 +1,7 @@
 use std::{fmt, sync::Arc, time::Duration};
 
+use actix_web::dev::Service;
 use derive_more::{Display, Error, From};
-use hyper::service::Service;
 use lru_time_cache::LruCache;
 use tokio::sync::Mutex;
 
@@ -65,7 +65,7 @@ where
             cache = "miss",
         );
 
-        let mut service = self.inner.clone();
+        let service = self.inner.clone();
         let fresh = service.call(req.clone()).await?;
 
         {

src/utils/common.rs

@@ -0,0 +1,150 @@
+use either::Either;
+use serde::{Deserialize, Serialize};
+use serde_with::{DeserializeFromStr, SerializeDisplay};
+use std::{
+    fmt::{self, Debug, Display, Formatter},
+    str::FromStr,
+};
+
+/// An `untagged` version of `Either`.
+///
+/// The reason this structure is needed is that `either::Either` is
+/// by default an `Externally Tagged` enum, and it is possible to
+/// implement `untagged` via `#[serde(with = "either::serde_untagged_optional")]`
+/// as well. But this approach can cause problems with deserialization,
+/// resulting in having to manually add the `#[serde(default)]` tag,
+/// and this leads to less readable as well as less flexible code.
+/// So it would be better if we manually implement this `UntaggedEither` here,
+/// while providing a two-way conversion to `either::Either`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum UntaggedEither<L, R> {
+    Left(L),
+    Right(R),
+}
+
+impl<L, R> From<UntaggedEither<L, R>> for Either<L, R> {
+    fn from(value: UntaggedEither<L, R>) -> Self {
+        match value {
+            UntaggedEither::Left(l) => Self::Left(l),
+            UntaggedEither::Right(r) => Self::Right(r),
+        }
+    }
+}
+
+impl<L, R> From<Either<L, R>> for UntaggedEither<L, R> {
+    fn from(value: Either<L, R>) -> Self {
+        match value {
+            Either::Left(l) => UntaggedEither::Left(l),
+            Either::Right(r) => UntaggedEither::Right(r),
+        }
+    }
+}
+
+/// A generic newtype which serialized using `Display` and deserialized using `FromStr`.
+#[derive(Default, Clone, DeserializeFromStr, SerializeDisplay)]
+pub struct SerdeDisplayFromStr<T>(pub T);
+
+impl<T: Debug> Debug for SerdeDisplayFromStr<T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        Debug::fmt(&self.0, f)
+    }
+}
+
+impl<T: Display> Display for SerdeDisplayFromStr<T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        Display::fmt(&self.0, f)
+    }
+}
+
+impl<T: FromStr> FromStr for SerdeDisplayFromStr<T> {
+    type Err = T::Err;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        s.parse::<T>().map(Self)
+    }
+}
+
+/// The reason it's needed here is that using `Deserialize` generated
+/// by default by `serde` will cause deserialization to fail if
+/// both untyped formats (such as `urlencoded`) and `untagged enum`
+/// are used. The Wrap type here forces the deserialization process to
+/// be delegated to `FromStr`.
+pub type WrappedBool = SerdeDisplayFromStr<bool>;
+
+/// Returns truncated string accounting for multi-byte characters.
+pub(crate) fn safe_truncate(s: &str, len: usize) -> &str {
+    if len == 0 {
+        return "";
+    }
+
+    if s.len() <= len {
+        return s;
+    }
+
+    if s.is_char_boundary(len) {
+        return &s[0..len];
+    }
+
+    // Only 3 cases possible: 1, 2, or 3 bytes need to be removed for a new,
+    // valid UTF-8 string to appear when truncated, just enumerate them,
+    // Underflow is not possible since position 0 is always a valid boundary.
+
+    if let Some((slice, _rest)) = s.split_at_checked(len - 1) {
+        return slice;
+    }
+
+    if let Some((slice, _rest)) = s.split_at_checked(len - 2) {
+        return slice;
+    }
+
+    if let Some((slice, _rest)) = s.split_at_checked(len - 3) {
+        return slice;
+    }
+
+    unreachable!("all branches covered");
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn safe_truncation() {
+        assert_eq!(safe_truncate("", 0), "");
+        assert_eq!(safe_truncate("", 1), "");
+        assert_eq!(safe_truncate("", 9), "");
+
+        assert_eq!(safe_truncate("a", 0), "");
+        assert_eq!(safe_truncate("a", 1), "a");
+        assert_eq!(safe_truncate("a", 9), "a");
+
+        assert_eq!(safe_truncate("lorem\nipsum", 0), "");
+        assert_eq!(safe_truncate("lorem\nipsum", 5), "lorem");
+        assert_eq!(safe_truncate("lorem\nipsum", usize::MAX), "lorem\nipsum");
+
+        assert_eq!(safe_truncate("café", 1), "c");
+        assert_eq!(safe_truncate("café", 2), "ca");
+        assert_eq!(safe_truncate("café", 3), "caf");
+        assert_eq!(safe_truncate("café", 4), "caf");
+        assert_eq!(safe_truncate("café", 5), "café");
+
+        // 2-byte char
+        assert_eq!(safe_truncate("é", 0), "");
+        assert_eq!(safe_truncate("é", 1), "");
+        assert_eq!(safe_truncate("é", 2), "é");
+
+        // 3-byte char
+        assert_eq!(safe_truncate("⊕", 0), "");
+        assert_eq!(safe_truncate("⊕", 1), "");
+        assert_eq!(safe_truncate("⊕", 2), "");
+        assert_eq!(safe_truncate("⊕", 3), "⊕");
+
+        // 4-byte char
+        assert_eq!(safe_truncate("🦊", 0), "");
+        assert_eq!(safe_truncate("🦊", 1), "");
+        assert_eq!(safe_truncate("🦊", 2), "");
+        assert_eq!(safe_truncate("🦊", 3), "");
+        assert_eq!(safe_truncate("🦊", 4), "🦊");
+    }
+}

src/utils/mod.rs

@@ -1,2 +1,3 @@
 pub mod cache;
+pub mod common;
 pub mod index;