cache and installation

README.md

@@ -23,8 +23,12 @@ $ curl -G https://example.com/svg \
     -d 'transparent=1' \
 ```
 
+the server sets the `cache-control` header to `max-age=3600, stale-while-revalidate=21600` so clients cache the response(s) for an hour and revalidate within 6.
+
 ## installation
 
+### docker
+
 ```bash
 # Pull the Docker image
 $ docker pull ghcr.io/ari-party/umami-views:latest
@@ -35,3 +39,18 @@ $ docker run -d --name umami-views -p 8080:8080 ghcr.io/ari-party/umami-views:la
 # `-p 8080:8080`, replace the lefthand 8080 with a port that you prefer,
 #                 the server will be available on that port for you
 ```
+
+### manual
+
+```bash
+# Clone the repository
+$ git clone https://github.com/ari-party/umami-views.git
+
+# Install the dependencies with pnpm (install with `npm i -g pnpm`)
+$ pnpm install
+
+# Copy the `.env.example` file as `.env` and edit the port to your wish
+
+# Start the server
+$ pnpm start
+```

src/index.ts

@@ -94,9 +94,9 @@ app.get('/svg', async (req, res) => {
 
     res
       .setHeader('content-type', 'image/svg+xml;charset=utf-8')
-      .setHeader('cache-control', 'max-age=60, must-revalidate')
+      .setHeader('cache-control', 'max-age=3600, stale-while-revalidate=21600')
       .setHeader('date', String(new Date()))
-      .setHeader('expires', String(new Date(Date.now() + 60_000)))
+      .setHeader('expires', String(new Date(Date.now() + 3_600 * 1_000)))
       .send(optimized);
   } catch (error) {
     console.warn(error);