* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
-
package org.opendaylight.mdsal.dom.api;
-import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionChainFactory;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
-import org.opendaylight.controller.sal.core.api.BrokerService;
-import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.opendaylight.yangtools.concepts.Registration;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
/**
- * Data Broker which provides data transaction and data change listener functionality
- * using {@link NormalizedNode} data format.
+ * Data Broker which provides data transaction and data change listener functionality using {@link NormalizedNode}.
+ *
+ * <p>
+ * All operations on the data tree are performed via one of the transactions:
+ * <ul>
+ * <li>Read-Only - allocated using {@link #newReadOnlyTransaction()}
+ * <li>Write-Only - allocated using {@link #newWriteOnlyTransaction()}
+ * </ul>
+ *
+ * <p>
+ * These transactions provide a stable isolated view of data tree, which is guaranteed to be not
+ * affected by other concurrent transactions, until transaction is committed.
*
- * This interface is type capture of generic interfaces and returns type captures
- * of results for client-code convenience.
+ * <p>
+ * For a detailed explanation of how transaction are isolated and how transaction-local changes are
+ * committed to global data tree, see {@link DOMDataTreeReadTransaction}, {@link DOMDataTreeWriteTransaction}
+ * and {@link DOMDataTreeWriteTransaction#commit()}.
*
+ *
+ * <p>
+ * It is strongly recommended to use the type of transaction, which provides only the minimal
+ * capabilities you need. This allows for optimizations at the data broker / data store level. For
+ * example, implementations may optimize the transaction for reading if they know ahead of time that
+ * you only need to read data - such as not keeping additional meta-data, which may be required for
+ * write transactions.
+ *
+ * <p>
+ * <b>Implementation Note:</b> This interface is not intended to be implemented by users of MD-SAL,
+ * but only to be consumed by them.
*/
-public interface DOMDataBroker extends
- AsyncDataBroker<YangInstanceIdentifier, NormalizedNode<?, ?>, DOMDataChangeListener>,
- TransactionChainFactory<YangInstanceIdentifier, NormalizedNode<?, ?>>, BrokerService, DOMExtensibleService<DOMDataBroker, DOMDataBrokerExtension> {
-
+@NonNullByDefault
+public interface DOMDataBroker extends DOMService<DOMDataBroker, DOMDataBroker.Extension>, DOMTransactionFactory {
/**
- * {@inheritDoc}
+ * Type capture of a {@link DOMService.Extension} applicable to {@link DOMDataBroker} implementations.
*/
- @Override
- DOMDataReadOnlyTransaction newReadOnlyTransaction();
+ interface Extension extends DOMService.Extension<DOMDataBroker, Extension> {
+ // Marker interface
+ }
/**
- * {@inheritDoc}
+ * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
+ * no outstanding transaction.
+ *
+ * @return A new transaction chain.
*/
- @Override
- DOMDataReadWriteTransaction newReadWriteTransaction();
+ DOMTransactionChain createTransactionChain();
/**
- * {@inheritDoc}
+ * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
+ * no outstanding transaction.
+ *
+ * <p>
+ * Unlike {@link #createTransactionChain()}, the transaction chain returned by this method is allowed to merge
+ * individual transactions into larger chunks. When transactions are merged, the results must be indistinguishable
+ * from the result of all operations having been performed on a single transaction.
+ *
+ * <p>
+ * When transactions are merged, {@link DOMTransactionChain#newReadOnlyTransaction()} may actually be backed by
+ * a read-write transaction, hence an additional restriction on API use is that multiple read-only transactions
+ * may not be open at the same time.
+ *
+ * @return A new transaction chain.
*/
- @Override
- DOMDataWriteTransaction newWriteOnlyTransaction();
+ DOMTransactionChain createMergingTransactionChain();
/**
- * {@inheritDoc}
+ * Optional support for allowing a {@link DOMDataTreeCommitCohort} to participate in the process of committing
+ * {@link DOMDataTreeWriteTransaction}s.
*/
- @Override
- DOMTransactionChain createTransactionChain(TransactionChainListener listener);
+ interface CommitCohortExtension extends Extension {
+ /**
+ * Register commit cohort which will participate in three-phase commit protocols of
+ * {@link DOMDataTreeWriteTransaction} in data broker associated with this instance of extension.
+ *
+ * @param path Subtree path on which commit cohort operates.
+ * @param cohort A {@link DOMDataTreeCommitCohort}
+ * @return A {@link Registration}
+ * @throws NullPointerException if any argument is {@code null}
+ */
+ Registration registerCommitCohort(DOMDataTreeIdentifier path, DOMDataTreeCommitCohort cohort);
+ }
}
Code Review / mdsal.git / blobdiff