Ability throw checked exceptions from transactionManager

Author: IlyaMoiseev

services/src/kilda-core/kilda-persistence-api/src/main/java/org/openkilda/persistence/TransactionCallback.java

@@ -21,6 +21,6 @@
  * @param <T> The return type of the callback.
  */
 @FunctionalInterface
-public interface TransactionCallback<T> {
-    T doInTransaction();
+public interface TransactionCallback<T, E extends Exception> {
+    T doInTransaction() throws E;
 }

services/src/kilda-core/kilda-persistence-api/src/main/java/org/openkilda/persistence/TransactionCallbackWithoutResult.java

@@ -19,6 +19,6 @@
  * Callback to be executed inside an managed transaction.
  */
 @FunctionalInterface
-public interface TransactionCallbackWithoutResult {
-    void doInTransaction();
+public interface TransactionCallbackWithoutResult<E extends Exception> {
+    void doInTransaction() throws E;
 }

services/src/kilda-core/kilda-persistence-api/src/main/java/org/openkilda/persistence/TransactionManager.java

@@ -28,7 +28,7 @@ public interface TransactionManager {
      * @param action the transactional action
      * @return a result returned by the callback
      */
-    <T> T doInTransaction(TransactionCallback<T> action);
+    <T, E extends Exception> T doInTransaction(TransactionCallback<T, E> action);
 
     /**
      * Execute the action specified by the given callback within a transaction.
@@ -38,5 +38,5 @@ public interface TransactionManager {
      *
      * @param action the transactional action
      */
-    void doInTransaction(TransactionCallbackWithoutResult action);
+    <E extends Exception> void doInTransaction(TransactionCallbackWithoutResult<E> action);
 }

services/src/kilda-core/kilda-persistence-neo4j/src/main/java/org/openkilda/persistence/Neo4jTransactionManager.java

@@ -18,6 +18,7 @@
 import org.openkilda.persistence.repositories.impl.Neo4jSessionFactory;
 
 import com.google.common.annotations.VisibleForTesting;
+import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
 import org.neo4j.ogm.session.Session;
 import org.neo4j.ogm.session.SessionFactory;
@@ -49,8 +50,9 @@ public Session getSession() {
         return Optional.ofNullable(SESSION_HOLDER.get()).orElseGet(sessionFactory::openSession);
     }
 
+    @SneakyThrows
     @Override
-    public <T> T doInTransaction(TransactionCallback<T> action) {
+    public <T, E extends Exception> T doInTransaction(TransactionCallback<T, E> action) {
         begin();
 
         try {
@@ -63,8 +65,9 @@ public <T> T doInTransaction(TransactionCallback<T> action) {
         }
     }
 
+    @SneakyThrows
     @Override
-    public void doInTransaction(TransactionCallbackWithoutResult action) {
+    public <E extends Exception> void doInTransaction(TransactionCallbackWithoutResult<E> action) {
         begin();
 
         try {

services/src/kilda-core/kilda-persistence-neo4j/src/test/java/org/openkilda/persistence/Neo4jTransactionManagerTest.java

@@ -148,4 +148,27 @@ public void shouldRollbackExtendedAndRootTx() {
         // then
         assertEquals(0, repository.findAll().size());
     }
+
+    @Test(expected = TestCheckedException.class)
+    public void shouldCheckedExceptionThrown() {
+        // when
+        txManager.doInTransaction(() -> {
+            throw new TestCheckedException();
+        });
+
+        fail();
+    }
+
+    @Test(expected = TestCheckedException.class)
+    public void shouldCheckedExceptionThrownWithoutResult() {
+        // when
+        txManager.doInTransaction((TransactionCallbackWithoutResult<TestCheckedException>) () -> {
+            throw new TestCheckedException();
+        });
+
+        fail();
+    }
+
+    private class TestCheckedException extends Exception {
+    }
 }

services/wfm/src/main/java/org/openkilda/wfm/topology/flow/service/FlowService.java

@@ -51,7 +51,6 @@
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 
@@ -228,34 +227,25 @@ public FlowPair updateFlow(Flow updatingFlow, String diverseFlowId, FlowCommandS
             SwitchValidationException {
         flowValidator.validate(updatingFlow);
 
-        if (diverseFlowId != null && !doesFlowExist(diverseFlowId)) {
-            throw new FlowNotFoundException(diverseFlowId);
-        }
-
-        // TODO: the strategy is defined either per flow or system-wide.
-        PathComputer pathComputer = pathComputerFactory.getPathComputer();
-        PathPair pathPair = pathComputer.getPath(updatingFlow, true);
-
         updatingFlow.setStatus(FlowStatus.IN_PROGRESS);
 
         UpdatedFlowPairWithSegments result = transactionManager.doInTransaction(() -> {
-            Optional<FlowPair> foundFlowPair = getFlowPair(updatingFlow.getFlowId());
-            if (!foundFlowPair.isPresent()) {
-                return Optional.<UpdatedFlowPairWithSegments>empty();
-            }
+            FlowPair currentFlow = getFlowPair(updatingFlow.getFlowId())
+                    .orElseThrow(() -> new FlowNotFoundException(updatingFlow.getFlowId()));
 
-            FlowPair currentFlow = foundFlowPair.get();
+            if (diverseFlowId != null && !doesFlowExist(diverseFlowId)) {
+                throw new FlowNotFoundException(diverseFlowId);
+            }
 
-            // group id update
-            updatingFlow.setGroupId(currentFlow.getForward().getGroupId());
-            if (diverseFlowId != null) {
-                if (Objects.equals(updatingFlow.getFlowId(), diverseFlowId)) {
-                    updatingFlow.setGroupId(null);
-                } else {
-                    updatingFlow.setGroupId(getOrCreateFlowGroupId(diverseFlowId));
-                }
+            if (diverseFlowId == null) {
+                updatingFlow.setGroupId(null);
+            } else {
+                updatingFlow.setGroupId(getOrCreateFlowGroupId(diverseFlowId));
             }
 
+            PathComputer pathComputer = pathComputerFactory.getPathComputer();
+            PathPair pathPair = pathComputer.getPath(updatingFlow, true);
+
             List<FlowSegment> forwardSegments = getFlowSegments(currentFlow.getForward());
             List<FlowSegment> reverseSegments = getFlowSegments(currentFlow.getReverse());
             List<FlowSegment> flowSegments = union(forwardSegments, reverseSegments);
@@ -278,11 +268,11 @@ public FlowPair updateFlow(Flow updatingFlow, String diverseFlowId, FlowCommandS
 
             flowResourcesManager.deallocateFlow(currentFlow);
 
-            return Optional.of(UpdatedFlowPairWithSegments.builder()
+            return UpdatedFlowPairWithSegments.builder()
                     .oldFlowPair(currentFlow).oldForwardSegments(forwardSegments).oldReverseSegments(reverseSegments)
                     .flowPair(newFlowWithResources).forwardSegments(newForwardSegments)
-                    .reverseSegments(newReverseSegments).build());
-        }).orElseThrow(() -> new FlowNotFoundException(updatingFlow.getFlowId()));
+                    .reverseSegments(newReverseSegments).build();
+        });
 
         // To avoid race condition in DB updates, we should send commands only after DB transaction commit.
         sender.sendUpdateRulesCommand(result);