use lock

src/app.service.ts

@@ -27,22 +27,24 @@ export class AppService extends ConsoleLogger {
     const url = req.originalUrl.startsWith('/')
       ? req.originalUrl.slice(1)
       : req.originalUrl;
-    const siteCache = await this.aragami.get(SiteCache, url);
-    if (siteCache) {
-      this.log(`Cache hit for ${url}`);
-      return siteCache.html;
-    }
-    this.log(`Rendering ${url}`);
-    try {
-      const html = await this.puppeteerService.render(url);
-      await this.aragami.set(SiteCache, { url, html });
-      return html;
-    } catch (e) {
-      this.error(`Error rendering ${url}`, e);
-      throw new BlankReturnMessageDto(
-        404,
-        `Page not found: ${url}`,
-      ).toException();
-    }
+    return this.aragami.lock(url, async () => {
+      const siteCache = await this.aragami.get(SiteCache, url);
+      if (siteCache) {
+        this.log(`Cache hit for ${url}`);
+        return siteCache.html;
+      }
+      this.log(`Rendering ${url}`);
+      try {
+        const html = await this.puppeteerService.render(url);
+        await this.aragami.set(SiteCache, { url, html });
+        return html;
+      } catch (e) {
+        this.error(`Error rendering ${url}`, e);
+        throw new BlankReturnMessageDto(
+          404,
+          `Page not found: ${url}`,
+        ).toException();
+      }
+    });
   }
 }