Move a transaction block into the task db extension methods.

Author: isoos

app/lib/task/backend.dart

@@ -1382,9 +1382,7 @@ final class _TaskDataAccess {
     return await withRetryTransaction(_db, (tx) async {
       // Reload [state] within a transaction to avoid overwriting changes
       // made by others trying to update state for another package.
-      final s = await tx.lookupOrNull<PackageState>(
-        PackageState.createKey(_db.emptyKey, runtimeVersion, package),
-      );
+      final s = await tx.tasks.lookupOrNull(package);
       if (s == null) {
         // No entry has been created yet, probably because of a new deployment rolling out.
         // We can ignore it for now.
@@ -1404,18 +1402,35 @@ final class _TaskDataAccess {
 
   Future<void> bumpPriority(String packageName) async {
     await withRetryTransaction(_db, (tx) async {
-      final stateKey = PackageState.createKey(
-        _db.emptyKey,
-        runtimeVersion,
-        packageName,
-      );
-      final state = await tx.lookupOrNull<PackageState>(stateKey);
+      final state = await tx.tasks.lookupOrNull(packageName);
       if (state != null) {
         state.pendingAt = initialTimestamp;
         tx.insert(state);
       }
     });
   }
+
+  /// Restores the previous versions map state when starting the tasks on [instanceName] failed.
+  Future<void> restorePreviousVersionsState(
+    String packageName,
+    String instanceName,
+    Map<String, PackageVersionStateInfo> previousVersionsMap,
+  ) async {
+    await withRetryTransaction(_db, (tx) async {
+      final s = await tx.tasks.lookupOrNull(packageName);
+      if (s == null) {
+        return; // Presumably, the package was deleted.
+      }
+
+      s.versions!.addEntries(
+        s.versions!.entries
+            .where((e) => e.value.instance == instanceName)
+            .map((e) => MapEntry(e.key, previousVersionsMap[e.key]!)),
+      );
+      s.derivePendingAt();
+      await tx.tasks.update(s);
+    });
+  }
 }
 
 class _TaskTransactionDataAcccess {

app/lib/task/scheduler.dart

@@ -10,7 +10,6 @@ import 'package:pub_dev/package/backend.dart';
 import 'package:pub_dev/shared/configuration.dart';
 import 'package:pub_dev/shared/datastore.dart';
 import 'package:pub_dev/shared/utils.dart';
-import 'package:pub_dev/shared/versions.dart' show runtimeVersion;
 import 'package:pub_dev/task/backend.dart';
 import 'package:pub_dev/task/clock_control.dart';
 import 'package:pub_dev/task/cloudcompute/cloudcompute.dart';
@@ -237,26 +236,11 @@ Future<void> schedule(
               // suppose to run on the instance we just failed to create.
               // If this doesn't work, we'll eventually retry. Hence, correctness
               // does not hinge on this transaction being successful.
-              await withRetryTransaction(db, (tx) async {
-                final s = await tx.lookupOrNull<PackageState>(
-                  PackageState.createKey(
-                    db.emptyKey,
-                    runtimeVersion,
-                    selected.package,
-                  ),
-                );
-                if (s == null) {
-                  return; // Presumably, the package was deleted.
-                }
-
-                s.versions!.addEntries(
-                  s.versions!.entries
-                      .where((e) => e.value.instance == instanceName)
-                      .map((e) => MapEntry(e.key, oldVersionsMap[e.key]!)),
-                );
-                s.derivePendingAt();
-                tx.insert(s);
-              });
+              await db.tasks.restorePreviousVersionsState(
+                selected.package,
+                instanceName,
+                oldVersionsMap,
+              );
             }
           }
         });
@@ -295,9 +279,7 @@ updatePackageStateWithPendingVersions(
   String instanceName,
 ) async {
   return await withRetryTransaction(db, (tx) async {
-    final s = await tx.lookupOrNull<PackageState>(
-      PackageState.createKey(db.emptyKey, runtimeVersion, package),
-    );
+    final s = await tx.tasks.lookupOrNull(package);
     if (s == null) {
       // presumably the package was deleted.
       return null;
@@ -360,7 +342,7 @@ updatePackageStateWithPendingVersions(
         ),
     });
     s.derivePendingAt();
-    tx.insert(s);
+    await tx.tasks.update(s);
 
     // Create payload
     final payload = Payload(