Retry storage list operations using retried pagination.

app/lib/package/api_export/exported_api.dart

@@ -149,7 +149,8 @@ final class ExportedApi {
   Future<void> _gcOldPrefixes() async {
     // List all top-level prefixes, and delete the ones we don't need
     final topLevelprefixes = await _pool.withResource(
-      () async => await _bucket.list(prefix: '', delimiter: '/').toList(),
+      () async =>
+          await _bucket.listAllItemsWithRetry(prefix: '', delimiter: '/'),
     );
     await Future.wait(topLevelprefixes.map((entry) async {
       if (entry.isObject) {

app/lib/package/tarball_storage.dart

@@ -67,12 +67,10 @@ class TarballStorage {
     String package,
   ) async {
     final prefix = _tarballObjectNamePackagePrefix(package);
-    final items = await _canonicalBucket
-        .list(
-          prefix: prefix,
-          delimiter: '',
-        )
-        .toList();
+    final items = await _canonicalBucket.listAllItemsWithRetry(
+      prefix: prefix,
+      delimiter: '',
+    );
     return Map.fromEntries(items.whereType<BucketObjectEntry>().map((item) {
       final version = item.name.without(prefix: prefix, suffix: '.tar.gz');
       return MapEntry(
@@ -255,32 +253,33 @@ class TarballStorage {
     final filterForNamePrefix = package == null
         ? 'packages/'
         : _tarballObjectNamePackagePrefix(package);
-    await for (final entry in _publicBucket.list(prefix: filterForNamePrefix)) {
+    await _publicBucket.listWithRetry(prefix: filterForNamePrefix,
+        (entry) async {
       // Skip non-objects.
       if (!entry.isObject) {
-        continue;
+        return;
       }
       // Skip objects that were matched in the previous step.
       if (objectNamesInPublicBucket.contains(entry.name)) {
-        continue;
+        return;
       }
       if (deleteObjects.contains(entry.name)) {
-        continue;
+        return;
       }
 
       final publicInfo = await _publicBucket.tryInfo(entry.name);
       if (publicInfo == null) {
         _logger.warning(
             'Failed to get info for public bucket object "${entry.name}".');
-        continue;
+        return;
       }
 
       await updateContentDispositionToAttachment(publicInfo, _publicBucket);
 
       // Skip recently updated objects.
       if (publicInfo.age < ageCheckThreshold) {
         // Ignore recent files.
-        continue;
+        return;
       }
 
       final canonicalInfo = await _canonicalBucket.tryInfo(entry.name);
@@ -289,11 +288,11 @@ class TarballStorage {
         // but it wasn't matched through the [PackageVersion] query above.
         if (canonicalInfo.age < ageCheckThreshold) {
           // Ignore recent files.
-          continue;
+          return;
         }
         _logger.severe(
             'Object without matching PackageVersion in canonical and public buckets: "${entry.name}".');
-        continue;
+        return;
       } else {
         // The object in the public bucket has no matching file in the canonical bucket.
         // We can assume it is stale and can delete it.
@@ -305,7 +304,7 @@ class TarballStorage {
           deleteObjects.add(entry.name);
         }
       }
-    }
+    });
 
     for (final objectName in deleteObjects) {
       _logger.shout('Deleting object from public bucket: "$objectName".');

app/lib/service/download_counts/sync_download_counts.dart

@@ -64,7 +64,8 @@ Future<Set<String>> processDownloadCounts(DateTime date) async {
 
   final failedFiles = <String>{};
 
-  final bucketEntries = await bucket.list(prefix: fileNamePrefix).toList();
+  final bucketEntries =
+      await bucket.listAllItemsWithRetry(prefix: fileNamePrefix);
 
   if (bucketEntries.isEmpty) {
     _logger.info('Failed to read any files with prefix "$fileNamePrefix"./n');

app/lib/shared/storage.dart

@@ -188,6 +188,36 @@ extension BucketExt on Bucket {
     return await _retry(() async => fn(read(objectName)));
   }
 
+  /// List objects in the bucket with default retry with pagination.
+  Future<void> listWithRetry(
+    FutureOr<void> Function(BucketEntry input) fn, {
+    String? prefix,
+    String? delimiter,
+  }) async {
+    for (;;) {
+      var p = await pageWithRetry(prefix: prefix, delimiter: delimiter);
+      for (final item in p.items) {
+        await fn(item);
+      }
+      if (p.isLast) break;
+      p = await p.nextWithRetry();
+    }
+  }
+
+  /// Lists all entries with default retry pagination, returns them as List.
+  Future<List<BucketEntry>> listAllItemsWithRetry({
+    String? prefix,
+    String? delimiter,
+  }) async {
+    final entries = <BucketEntry>[];
+    await listWithRetry(
+      prefix: prefix,
+      delimiter: delimiter,
+      entries.add,
+    );
+    return entries;
+  }
+
   /// The HTTP URL of a publicly accessable GCS object.
   String objectUrl(String objectName) {
     return '${activeConfiguration.storageBaseUrl}/$bucketName/$objectName';
@@ -324,8 +354,9 @@ Future<int> deleteBucketFolderRecursively(
     page = await retry(
       () async {
         return page == null
-            ? await bucket.page(prefix: folder, delimiter: '', pageSize: 100)
-            : await page.next(pageSize: 100);
+            ? await bucket.pageWithRetry(
+                prefix: folder, delimiter: '', pageSize: 100)
+            : await page.nextWithRetry(pageSize: 100);
       },
       delayFactor: Duration(seconds: 10),
       maxAttempts: 3,
@@ -430,8 +461,7 @@ class VersionedJsonStorage {
     }
     // fallback to earlier runtimes
     final currentPath = _objectName();
-    final list = await _bucket
-        .list(prefix: _prefix)
+    final list = (await _bucket.listAllItemsWithRetry(prefix: _prefix))
         .map((entry) => entry.name)
         .where((name) => name.endsWith(_extension))
         .where((name) => name.compareTo(currentPath) <= 0)
@@ -456,19 +486,19 @@ class VersionedJsonStorage {
   Future<DeleteCounts> deleteOldData({Duration? minAgeThreshold}) async {
     var found = 0;
     var deleted = 0;
-    await for (final entry in _bucket.list(prefix: _prefix)) {
+    await _bucket.listWithRetry(prefix: _prefix, (entry) async {
       if (entry.isDirectory) {
-        continue;
+        return;
       }
       final name = p.basename(entry.name);
       if (!name.endsWith(_extension)) {
-        continue;
+        return;
       }
       final version = name.substring(0, name.length - _extension.length);
       final matchesPattern = version.length == 10 &&
           versions.runtimeVersionPattern.hasMatch(version);
       if (!matchesPattern) {
-        continue;
+        return;
       }
       found++;
       if (versions.shouldGCVersion(version)) {
@@ -479,7 +509,7 @@ class VersionedJsonStorage {
           await deleteFromBucket(_bucket, entry.name);
         }
       }
-    }
+    });
     return DeleteCounts(found, deleted);
   }
 

app/lib/task/backend.dart

@@ -516,10 +516,10 @@ class TaskBackend {
     // Objects in the bucket are stored under the following pattern:
     //   `<runtimeVersion>/<package>/<version>/...`
     // Thus, we list with `/` as delimiter and get a list of runtimeVersions
-    await for (final d in _bucket.list(prefix: '', delimiter: '/')) {
+    await _bucket.listWithRetry(prefix: '', delimiter: '/', (d) async {
       if (!d.isDirectory) {
         _log.warning('bucket should not contain any top-level object');
-        continue;
+        return;
       }
 
       // Remove trailing slash from object prefix, to get a runtimeVersion
@@ -529,7 +529,7 @@ class TaskBackend {
       // Check if the runtimeVersion should be GC'ed
       if (shouldGCVersion(rtVersion)) {
         // List all objects under the `<rtVersion>/`
-        await for (final obj in _bucket.list(prefix: d.name, delimiter: '')) {
+        await _bucket.listWithRetry(prefix: d.name, delimiter: '', (obj) async {
           // Limit concurrency
           final r = await pool.request();
 
@@ -545,9 +545,9 @@ class TaskBackend {
               r.release(); // always release to avoid deadlock
             }
           });
-        }
+        });
       }
-    }
+    });
 
     // Close the pool, and wait for all pending deletion request to complete.
     await pool.close();

pkg/fake_gcloud/lib/retry_enforcer_storage.dart

@@ -141,6 +141,7 @@ class _RetryEnforcerBucket implements Bucket {
   @override
   Stream<BucketEntry> list({String? prefix, String? delimiter}) {
     // TODO: verify retry wrapper here
+    _verifyRetryOnStack();
     return _bucket.list(
       prefix: prefix,
       delimiter: delimiter,