Search fallback: handle timeout, longer window. (dart-lang#7621)

szakarias · Apr 9, 2024 · 82c6015 · 82c6015
1 parent f70abec
commit 82c6015
Showing 1 changed file with 25 additions and 18 deletions.
diff --git a/app/lib/search/search_client.dart b/app/lib/search/search_client.dart
@@ -37,7 +37,7 @@ class SearchClient {
   /// Before this timestamp we may use the fallback search service URL, which
   /// is the unversioned service URL, potentially getting responses from an
   /// older instance.
-  final _fallbackSearchThreshold = clock.now().add(Duration(minutes: 10));
+  final _fallbackSearchThreshold = clock.now().add(Duration(minutes: 30));
 
   SearchClient([http.Client? client])
       : _httpClient = client ?? httpRetryClient(retries: 3);
@@ -58,34 +58,41 @@ class SearchClient {
 
     final serviceUrlParams = Uri(queryParameters: query.toUriQueryParameters());
 
-    Future<http.Response> doCallHttpServiceEndpoint({String? prefix}) async {
+    // returns null on timeout (after 5 seconds)
+    Future<http.Response?> doCallHttpServiceEndpoint({String? prefix}) async {
       final httpHostPort = prefix ?? activeConfiguration.searchServicePrefix;
       final serviceUrl = '$httpHostPort/search$serviceUrlParams';
-      return await _httpClient
-          .get(Uri.parse(serviceUrl), headers: cloudTraceHeaders())
-          .timeout(Duration(seconds: 5));
+      try {
+        return await _httpClient
+            .get(Uri.parse(serviceUrl), headers: cloudTraceHeaders())
+            .timeout(Duration(seconds: 5));
+      } on TimeoutException {
+        return null;
+      }
     }
 
     Future<PackageSearchResult> searchFn() async {
       // calling versioned endpoint
-      final response = await doCallHttpServiceEndpoint();
+      var response = await doCallHttpServiceEndpoint();
+      // if needed and possible, calling fallback request to unversioned endpoint
+      if (response == null || response.statusCode != 200) {
+        final serviceIsInStartup =
+            clock.now().isBefore(_fallbackSearchThreshold);
+        if (serviceIsInStartup &&
+            activeConfiguration.fallbackSearchServicePrefix != null) {
+          response = await doCallHttpServiceEndpoint(
+              prefix: activeConfiguration.fallbackSearchServicePrefix);
+        }
+      }
+      if (response == null) {
+        return PackageSearchResult.empty(
+            message: 'Search is temporarily unavailable.');
+      }
       if (response.statusCode == 200) {
         return PackageSearchResult.fromJson(
           json.decode(response.body) as Map<String, dynamic>,
         );
       }
-      // calling fallback request to unversioned endpoint
-      final serviceIsInStartup = clock.now().isBefore(_fallbackSearchThreshold);
-      if (serviceIsInStartup &&
-          activeConfiguration.fallbackSearchServicePrefix != null) {
-        final fallbackRs = await doCallHttpServiceEndpoint(
-            prefix: activeConfiguration.fallbackSearchServicePrefix);
-        if (fallbackRs.statusCode == 200) {
-          return PackageSearchResult.fromJson(
-            json.decode(fallbackRs.body) as Map<String, dynamic>,
-          );
-        }
-      }
       // Search request before the service initialization completed.
       if (response.statusCode == searchIndexNotReadyCode) {
         return PackageSearchResult.empty(