Merge pull request #19455 from overleaf/jpa-metrics

[misc] add metrics for document processing/broadcasting

GitOrigin-RevId: d81de0dfb7a91863547631580f3c85f569718130

services/web/frontend/js/features/ide-react/editor/document-container.ts

@@ -459,7 +459,7 @@ export class DocumentContainer extends EventEmitter {
         'joinDoc',
         this.doc_id,
         this.doc.getVersion(),
-        { encodeRanges: true },
+        { encodeRanges: true, age: this.doc.getTimeSinceLastServerActivity() },
         (error, docLines, version, updates, ranges) => {
           if (error) {
             callback?.(error)

services/web/frontend/js/features/ide-react/editor/share-js-doc.ts

@@ -257,6 +257,10 @@ export class ShareJsDoc extends EventEmitter {
     return this._doc.version
   }
 
+  getTimeSinceLastServerActivity() {
+    return Math.floor(performance.now() - this._doc.lastServerActivity)
+  }
+
   getType() {
     return this.type
   }