feat(swagger-ui): cache swagger zip

README.md

@@ -113,6 +113,7 @@ and the `ipa` is _api_ reversed. Aaand... `ipa` is also an awesome type of beer
 - **`rc_schema`**: Add `ToSchema` support for `Arc<T>` and `Rc<T>` types. **Note!** serde `rc` feature flag must be enabled separately to allow
   serialization and deserialization of `Arc<T>` and `Rc<T>` types. See more about [serde feature flags](https://serde.rs/feature-flags.html).
 - **`config`** Enables [`utoipa-config`](./utoipa-config/README.md) for the project which allows defining global configuration options for `utoipa`.
+- **`cache`** Enables caching of the Swagger UI download in `utoipa-swagger-ui` during the build process.
 
 ### Default Library Support
 

utoipa-swagger-ui/CHANGELOG.md

@@ -4,6 +4,10 @@
 
 ### Added
 
+* Add `cache` feature to cache swagger ui zip in build script (https://github.com/juhaku/utoipa/pull/1214)
+
+### Added
+
 * Allow disabling syntax highlighting (https://github.com/juhaku/utoipa/pull/1188)
 
 ## 8.0.3 - Oct 23 2024

utoipa-swagger-ui/Cargo.toml

@@ -18,6 +18,8 @@ debug-embed = ["rust-embed/debug-embed"]
 reqwest = ["dep:reqwest"]
 url = ["dep:url"]
 vendored = ["dep:utoipa-swagger-ui-vendored"]
+# cache swagger ui zip
+cache = ["dep:dirs", "dep:sha2"]
 
 [dependencies]
 rust-embed = { version = "8" }
@@ -40,14 +42,18 @@ tokio = { version = "1", features = ["macros"] }
 utoipa-swagger-ui = { path = ".", features = ["actix-web", "axum", "rocket"] }
 
 [package.metadata.docs.rs]
-features = ["actix-web", "axum", "rocket", "vendored"]
+features = ["actix-web", "axum", "rocket", "vendored", "cache"]
 no-default-features = true
 rustdoc-args = ["--cfg", "doc_cfg"]
 
 [build-dependencies]
 zip = { version = "2", default-features = false, features = ["deflate"] }
 regex = "1.7"
 
+# used by cache feature
+dirs = { version = "5.0.1", optional = true }
+sha2 = { version = "0.10.8", optional = true }
+
 # enabled optionally to allow rust only build with expense of bigger dependency tree and platform
 # independent build. By default `curl` system package is tried for downloading the Swagger UI.
 reqwest = { version = "0.12", features = [

utoipa-swagger-ui/build.rs

@@ -24,6 +24,20 @@ const SWAGGER_UI_DOWNLOAD_URL_DEFAULT: &str =
 const SWAGGER_UI_DOWNLOAD_URL: &str = "SWAGGER_UI_DOWNLOAD_URL";
 const SWAGGER_UI_OVERWRITE_FOLDER: &str = "SWAGGER_UI_OVERWRITE_FOLDER";
 
+#[cfg(feature = "cache")]
+fn sha256(data: &[u8]) -> String {
+    use sha2::{Digest, Sha256};
+    let mut hasher = Sha256::new();
+    hasher.update(data);
+    let hash = hasher.finalize();
+    format!("{:x}", hash).to_uppercase()
+}
+
+#[cfg(feature = "cache")]
+fn get_cache_dir() -> Option<PathBuf> {
+    dirs::cache_dir().map(|p| p.join("utoipa-swagger-ui"))
+}
+
 fn main() {
     let target_dir = env::var("OUT_DIR").unwrap();
     println!("OUT_DIR: {target_dir}");
@@ -137,7 +151,8 @@ impl SwaggerZip {
 
 fn get_zip_archive(url: &str, target_dir: &str) -> SwaggerZip {
     let zip_filename = url.split('/').last().unwrap().to_string();
-    let zip_path = [target_dir, &zip_filename].iter().collect::<PathBuf>();
+    #[allow(unused_mut)]
+    let mut zip_path = [target_dir, &zip_filename].iter().collect::<PathBuf>();
 
     if env::var("CARGO_FEATURE_VENDORED").is_ok() {
         #[cfg(not(feature = "vendored"))]
@@ -173,15 +188,37 @@ fn get_zip_archive(url: &str, target_dir: &str) -> SwaggerZip {
             .expect("failed to open file protocol copied Swagger UI");
         SwaggerZip::File(zip)
     } else if url.starts_with("http://") || url.starts_with("https://") {
-        println!("start download to : {:?}", zip_path);
-
         // with http protocol we update when the 'SWAGGER_UI_DOWNLOAD_URL' changes
         println!("cargo:rerun-if-env-changed={SWAGGER_UI_DOWNLOAD_URL}");
 
-        download_file(url, zip_path.clone())
-            .unwrap_or_else(|error| panic!("failed to download Swagger UI: {error}"));
-        let swagger_ui_zip =
-            File::open([target_dir, &zip_filename].iter().collect::<PathBuf>()).unwrap();
+        // Update zip_path to point to the resolved cache directory
+        #[cfg(feature = "cache")]
+        {
+            // Compute cache key based hashed URL + crate version
+            let mut cache_key = String::new();
+            cache_key.push_str(url);
+            cache_key.push_str(&env::var("CARGO_PKG_VERSION").unwrap_or_default());
+            let cache_key = sha256(cache_key.as_bytes());
+            // Store the cache in the cache_key directory inside the OS's default cache folder
+            let mut cache_dir = if let Some(dir) = get_cache_dir() {
+                dir.join("swagger-ui").join(&cache_key)
+            } else {
+                println!("cargo:warning=Could not determine cache directory, using OUT_DIR");
+                PathBuf::from(env::var("OUT_DIR").unwrap())
+            };
+            if fs::create_dir_all(&cache_dir).is_err() {
+                cache_dir = env::var("OUT_DIR").unwrap().into();
+            }
+            zip_path = cache_dir.join(&zip_filename);
+        }
+
+        if zip_path.exists() {
+            println!("using cached zip path from : {:?}", zip_path);
+        } else {
+            println!("start download to : {:?}", zip_path);
+            download_file(url, zip_path.clone()).expect("failed to download Swagger UI");
+        }
+        let swagger_ui_zip = File::open(zip_path).unwrap();
         let zip = ZipArchive::new(swagger_ui_zip).expect("failed to open downloaded Swagger UI");
         SwaggerZip::File(zip)
     } else {