Collapse Process tracks with More than 20 threads by default to impro…

…ve load performance.

PiperOrigin-RevId: 660111530

plugin/trace_viewer/tf_trace_viewer/tf-trace-viewer.html

@@ -1249,7 +1249,23 @@
           this._addDataResponseSize(data.length);
         }
         startUpdateModel = performance.now();
-        this._updateModel(data, replaceModel);
+        const jsonData = JSON.parse(data);
+        if (!this._model /* first load */) {
+          let traceViewerTraceModelSettings = JSON.parse(localStorage.getItem('trace-viewertrace_model_settings')) || {"value": {}};
+          for(const traceEvent of jsonData['traceEvents']) {
+            if (traceEvent['name'] !== undefined && traceEvent['name'] == 'process_name') {
+              // Collapse the process if it has more than 20 threads.
+              if (traceEvent['thread_count'] !== undefined && traceEvent['thread_count'] > 20) {
+                // Collapse the process only if preference is not set.
+                if (traceViewerTraceModelSettings['value']["processes."+traceEvent['args']['name']] === undefined) {
+                  traceViewerTraceModelSettings['value']["processes."+traceEvent['args']['name']] = {'expanded': false};
+                }
+              }
+            }
+          }
+          localStorage.setItem('trace-viewertrace_model_settings', JSON.stringify(traceViewerTraceModelSettings));
+        }
+        this._updateModel(jsonData, replaceModel);
         if (!this._isOss) {
           this._addUpdateModelLatency(performance.now() - startUpdateModel);
         }
@@ -1346,7 +1362,6 @@
     // the new data is merged with the old data.
     // Returns a void promise.
     _updateModel: function(data, replaceModel) {
-      data = JSON.parse(data);
       if (!this._model /* first load */ || replaceModel) {
         // Only give no events alert for first load or replace load
         if (!data['returnedEventsSize']) {