less commitSnapshots created

dhfs-parent/objects/src/main/java/com/usatiuk/objects/stores/WritebackObjectPersistentStore.java

@@ -307,6 +307,15 @@ public class WritebackObjectPersistentStore {
         return r -> asyncFence(bundleId, r);
     }
 
+    /**
+     * Get the last committed transaction ID.
+     *
+     * @return the last committed transaction ID
+     */
+    public long getLastCommitId() {
+        return _lastCommittedId.get();
+    }
+
     /**
      * Get a snapshot of the persistent store, including the pending writes.
      *

dhfs-parent/objects/src/main/java/com/usatiuk/objects/transaction/TransactionService.java

@@ -165,7 +165,6 @@ public class TransactionService {
                     toUnlock.add(lock);
                 }
 
-                commitSnapshot = writebackObjectPersistentStore.getSnapshot();
             } else {
                 Log.trace("Committing transaction - no changes");
 
@@ -201,7 +200,10 @@ public class TransactionService {
             Log.trace("Committing transaction start");
             var snapshotId = tx.snapshot().id();
 
-            if (snapshotId != commitSnapshot.id()) {
+            // All dependencies are locked and could not be changed concurrently now
+            if (snapshotId != writebackObjectPersistentStore.getLastCommitId()) {
+                commitSnapshot = writebackObjectPersistentStore.getSnapshot();
+
                 for (var read : readSet.entrySet()) {
                     var current = commitSnapshot.readObject(read.getKey());