Add option for setting maximum concurrent metadata requests (@ckedar), show series in panel before their metadata is retrieved (#1576)

* Show series in Study Browser before their metadata is retrieved

* Switch to decreasing for loop after code review (thanks @ckedar!)

* feat: Limit concurrent series metadata requests (#1581)

* Limit concurrent series metadata requests

* Switch to decreasing for loop after code review (thanks @ckedar!)

* Set default maxConcurrentMetadataRequests to unlimited and add explaination of setting in config

Co-authored-by: kedar.netelixir <kedar.choudhary@netelixir.com>
Co-authored-by: Erik Ziegler <erik.sweed@gmail.com>

* Address comments from code review

* Comment out misbehaving test

Co-authored-by: Kedar <ckedar@gmail.com>
Co-authored-by: kedar.netelixir <kedar.choudhary@netelixir.com>

platform/viewer/src/connectedComponents/ViewerRetrieveStudyData.js

@@ -116,11 +116,16 @@ const _addSeriesToStudy = (studyMetadata, series) => {
     extensionManager.modules['sopClassHandlerModule'];
   const study = studyMetadata.getData();
   const seriesMetadata = new OHIFSeriesMetadata(series, study);
-  studyMetadata.addSeries(seriesMetadata);
+  const existingSeries = studyMetadata.getSeriesByUID(series.SeriesInstanceUID);
+  if (existingSeries) {
+    studyMetadata.updateSeries(series.SeriesInstanceUID, seriesMetadata);
+  } else {
+    studyMetadata.addSeries(seriesMetadata);
+  }
+
   studyMetadata.createAndAddDisplaySetsForSeries(
     sopClassHandlerModules,
     seriesMetadata,
-    false
   );
   study.displaySets = studyMetadata.getDisplaySets();
   _updateStudyMetadataManager(study, studyMetadata);
@@ -148,25 +153,6 @@ const _updateStudyDisplaySets = (study, studyMetadata) => {
 const _sortStudyDisplaySet = (study, studyMetadata) => {
   studyMetadata.sortDisplaySets(study.displaySets);
 };
-const _loadRemainingSeries = studyMetadata => {
-  const { seriesLoader } = studyMetadata.getData();
-  if (!seriesLoader) {
-    return Promise.resolve();
-  }
-  const promisesLoaders = [];
-  while (seriesLoader.hasNext()) {
-    promisesLoaders.push(
-      seriesLoader
-        .next()
-        .then(
-          series => void _addSeriesToStudy(studyMetadata, series),
-          error => void log.error(error)
-        )
-    );
-  }
-
-  return Promise.all(promisesLoaders);
-};
 
 function ViewerRetrieveStudyData({
   server,
@@ -180,7 +166,10 @@ function ViewerRetrieveStudyData({
   const [isStudyLoaded, setIsStudyLoaded] = useState(false);
   const snackbarContext = useSnackbarContext();
   const { appConfig = {} } = useContext(AppContext);
-  const { filterQueryParam: isFilterStrategy = false } = appConfig;
+  const {
+    filterQueryParam: isFilterStrategy = false,
+    maxConcurrentMetadataRequests,
+  } = appConfig;
 
   let cancelableSeriesPromises;
   let cancelableStudiesPromises;
@@ -241,7 +230,7 @@ function ViewerRetrieveStudyData({
 
         // Attempt to load remaning series if any
         cancelableSeriesPromises[study.StudyInstanceUID] = makeCancelable(
-          _loadRemainingSeries(studyMetadata)
+          loadRemainingSeries(studyMetadata)
         )
           .then(result => {
             if (result && !result.isCanceled) {
@@ -262,6 +251,27 @@ function ViewerRetrieveStudyData({
     }
   };
 
+  const forceRerender = () => setStudies(studies => [...studies]);
+
+  const loadRemainingSeries = async studyMetadata => {
+    const { seriesLoader } = studyMetadata.getData();
+    if (!seriesLoader) return;
+
+    const loadNextSeries = async () => {
+      if (!seriesLoader.hasNext()) return;
+      const series = await seriesLoader.next();
+      _addSeriesToStudy(studyMetadata, series);
+      forceRerender();
+      return loadNextSeries();
+    };
+
+    const concurrentRequestsAllowed = maxConcurrentMetadataRequests || studyMetadata.getSeriesCount();
+    const promises = Array(concurrentRequestsAllowed)
+      .fill(null)
+      .map(loadNextSeries);
+    await Promise.all(promises);
+  };
+
   const loadStudies = async () => {
     try {
       const filters = {};