chore (backend-rs): cache generated icons

packages/backend-rs/index.d.ts

@@ -495,7 +495,7 @@ export declare function genId(): string
 /** Generate an ID using a specific datetime */
 export declare function genIdAt(date: Date): string
 
-export declare function genIdenticon(id: string): Buffer
+export declare function genIdenticon(id: string): Promise<Buffer>
 
 export declare function getFullApAccount(username: string, host?: string | undefined | null): string
 

packages/backend-rs/src/database/cache.rs

@@ -10,6 +10,7 @@ pub enum Category {
     Block,
     Follow,
     CatLang,
+    RandomIcon,
     #[cfg(test)]
     Test,
 }
@@ -35,6 +36,7 @@ fn categorize(category: Category, key: &str) -> String {
         Category::Block => "blocking",
         Category::Follow => "following",
         Category::CatLang => "catlang",
+        Category::RandomIcon => "randomIcon",
         #[cfg(test)]
         Category::Test => "usedOnlyForTesting",
     };

packages/backend-rs/src/misc/random_icon.rs

@@ -1,13 +1,29 @@
 use identicon_rs::{error::IdenticonError, Identicon};
+use crate::database::cache;
 
-pub fn generate(id: &str) -> Result<Vec<u8>, IdenticonError> {
-    Identicon::new(id).set_border(35).export_png_data()
+#[macros::errors]
+pub enum Error {
+    #[doc = "failed to generate identicon"]
+    #[error(transparent)]
+    Identicon(#[from] IdenticonError),
+    #[error("Redis cache operation has failed")]
+    Cache(#[from] cache::Error),
+}
+
+pub async fn generate(id: &str) -> Result<Vec<u8>, Error> {
+    if let Some(icon) = cache::get_one::<Vec<u8>>(cache::Category::RandomIcon, id).await? {
+        Ok(icon)
+    } else {
+        let icon = Identicon::new(id).set_border(35).export_png_data()?;
+        cache::set_one(cache::Category::RandomIcon, id, &icon, 10 * 60).await?;
+        Ok(icon)
+    }
 }
 
 #[cfg(feature = "napi")]
 #[napi_derive::napi(js_name = "genIdenticon")]
-pub fn generate_js(id: String) -> napi::Result<napi::bindgen_prelude::Buffer> {
-    match generate(&id) {
+pub async fn generate_js(id: String) -> napi::Result<napi::bindgen_prelude::Buffer> {
+    match generate(&id).await {
         Ok(icon) => Ok(icon.into()),
         Err(err) => Err(napi::Error::from_reason(format!(
             "\n{}\n",

packages/backend/src/server/index.ts

@@ -118,7 +118,7 @@ router.get("/avatar/@:acct", async (ctx) => {
 router.get("/identicon/:x", async (ctx) => {
 	const instanceMeta = await fetchMeta();
 	if (instanceMeta.enableIdenticonGeneration) {
-		const identicon = genIdenticon(ctx.params.x);
+		const identicon = await genIdenticon(ctx.params.x);
 		const [temp, cleanup] = await createTemp();
 		fs.createWriteStream(temp).write(identicon);
 		ctx.set("Content-Type", "image/png");