Allow enabling autocommit without an active transaction

Resolves: #3473

Author: ScottDugas

fdb-relational-api/src/main/java/com/apple/foundationdb/relational/api/RelationalConnection.java

@@ -157,6 +157,13 @@ default CallableStatement prepareCall(String sql, int resultSetType, int resultS
         throw new SQLFeatureNotSupportedException("Not implemented in the relational layer", ErrorCode.UNSUPPORTED_OPERATION.getErrorCode());
     }
 
+    @Override
+    default void commit() throws SQLException {
+        commit(false);
+    }
+
+    void commit(boolean onlyIfActive) throws SQLException;
+
     @Override
     @ExcludeFromJacocoGeneratedReport
     default String nativeSQL(String sql) throws SQLException {

fdb-relational-core/src/main/java/com/apple/foundationdb/relational/recordlayer/EmbeddedRelationalConnection.java

@@ -191,13 +191,17 @@ boolean canCommit() throws SQLException {
     }
 
     @Override
-    public void commit() throws SQLException {
+    public void commit(boolean onlyIfActive) throws SQLException {
         checkOpen();
         if (getAutoCommit()) {
             throw new RelationalException("commit called when the Connection is in auto-commit mode!", ErrorCode.CANNOT_COMMIT_ROLLBACK_WITH_AUTOCOMMIT).toSqlException();
         }
         if (!inActiveTransaction()) {
-            throw new RelationalException("No transaction to commit", ErrorCode.TRANSACTION_INACTIVE).toSqlException();
+            if (onlyIfActive) {
+                return;
+            } else {
+                throw new RelationalException("No transaction to commit", ErrorCode.TRANSACTION_INACTIVE).toSqlException();
+            }
         }
         commitInternal();
     }

fdb-relational-core/src/test/java/com/apple/foundationdb/relational/memory/InMemoryRelationalConnection.java

@@ -78,7 +78,7 @@ public boolean getAutoCommit() throws SQLException {
     }
 
     @Override
-    public void commit() throws SQLException {
+    public void commit(final boolean onlyIfActive) throws SQLException {
 
     }
 

fdb-relational-core/src/test/java/com/apple/foundationdb/relational/recordlayer/AutoCommitTests.java

@@ -520,7 +520,7 @@ public void changeAutoCommitBetweenTransactions() throws SQLException {
             // since the resultSet is closed but autoCommit is off, transaction will remain open.
             Assertions.assertTrue(conn.inActiveTransaction());
         }
-        Assertions.assertDoesNotThrow(conn::commit);
+        Assertions.assertDoesNotThrow(() -> conn.commit());
     }
 
     @Test
@@ -670,7 +670,7 @@ private static void checkAutoCommitAndCommitIfRequired(@Nonnull EmbeddedRelation
         } else {
             Assertions.assertFalse(connection.getAutoCommit());
             if (transactionType == TransactionType.AUTO_COMMIT_OFF_WITH_EXPLICIT_COMMIT) {
-                Assertions.assertDoesNotThrow(connection::commit);
+                Assertions.assertDoesNotThrow(() -> connection.commit());
             }
         }
     }

fdb-relational-core/src/test/java/com/apple/foundationdb/relational/recordlayer/RelationalConnectionRule.java

@@ -101,6 +101,11 @@ public void commit() throws SQLException {
         connection.commit();
     }
 
+    @Override
+    public void commit(final boolean onlyIfActive) throws SQLException {
+        connection.commit(onlyIfActive);
+    }
+
     @Override
     public void rollback() throws SQLException {
         connection.rollback();

fdb-relational-grpc/src/main/proto/grpc/relational/jdbc/v1/jdbc.proto

@@ -151,6 +151,8 @@ message StatementResponse {
 }
 
 message CommitRequest {
+  // If true, this will only commit if there is an active transaction
+  bool only_if_active = 1;
 }
 
 message CommitResponse {

fdb-relational-jdbc/src/main/java/com/apple/foundationdb/relational/jdbc/JDBCRelationalConnection.java

@@ -257,15 +257,15 @@ public InsertResponse insert(@Nonnull String tableName, @Nonnull List<Relational
     }
 
     @Override
-    @ExcludeFromJacocoGeneratedReport
-    public void commit() throws SQLException {
+    public void commit(final boolean onlyIfActive) throws SQLException {
         try {
             if (getAutoCommit()) {
                 throw new SQLException("Commit cannot be called when auto commit is ON");
             } else {
                 TransactionalRequest.Builder transactionRequest = TransactionalRequest.newBuilder()
-                        .setCommitRequest(CommitRequest.newBuilder().build());
-                // wait here for response
+                        .setCommitRequest(CommitRequest.newBuilder()
+                                .setOnlyIfActive(onlyIfActive).build());
+                // wait here for responsea
                 final TransactionalResponse response = serverConnection.sendRequest(transactionRequest.build());
                 checkForResponseError(response);
                 if (!response.hasCommitResponse()) {
@@ -345,7 +345,7 @@ public void setAutoCommit(boolean autoCommit) throws SQLException {
             this.autoCommit = false;
         } else {
             // commit any remaining work
-            commit();
+            commit(true);
             this.autoCommit = true;
             serverConnection.close();
             serverConnection = null;

fdb-relational-server/src/main/java/com/apple/foundationdb/relational/server/FRL.java

@@ -361,9 +361,11 @@ public int transactionalInsert(TransactionalToken token, String tableName, List<
         }
     }
 
-    public void transactionalCommit(TransactionalToken token) throws SQLException {
-        assertValidToken(token);
-        token.getConnection().commit();
+    public void transactionalCommit(TransactionalToken token, final boolean onlyIfActive) throws SQLException {
+        if (!(onlyIfActive && token == null)) {
+            assertValidToken(token);
+            token.getConnection().commit(onlyIfActive);
+        }
     }
 
     public void transactionalRollback(TransactionalToken token) throws SQLException {

fdb-relational-server/src/main/java/com/apple/foundationdb/relational/server/jdbc/v1/TransactionRequestHandler.java

@@ -103,7 +103,8 @@ public void onNext(final TransactionalRequest transactionRequest) {
             } else if (transactionRequest.hasCommitRequest()) {
                 // handle commit
                 logger.info("Handling commit request");
-                frl.transactionalCommit(transactionalToken);
+                frl.transactionalCommit(transactionalToken,
+                        transactionRequest.getCommitRequest().getOnlyIfActive());
                 responseBuilder.setCommitResponse(CommitResponse.newBuilder().build());
             } else if (transactionRequest.hasRollbackRequest()) {
                 // handle rollback