package org.opendaylight.mdsal.common.api;
import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.FluentFuture;
import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.MoreExecutors;
+import javax.annotation.CheckReturnValue;
+import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.yangtools.concepts.Path;
/**
* operation is complete. A successful commit returns nothing. On failure, the Future
* will fail with a {@link TransactionCommitFailedException} or an exception derived
* from TransactionCommitFailedException.
- *
* @throws IllegalStateException if the transaction is already submitted or was canceled.
+ * @deprecated Use {@link #commit()} instead.
*/
- CheckedFuture<Void,TransactionCommitFailedException> submit();
+ @Deprecated
+ CheckedFuture<Void, TransactionCommitFailedException> submit();
+ /**
+ * Submits this transaction to be asynchronously applied to update the logical data tree. The returned
+ * {@link FluentFuture} conveys the result of applying the data changes.
+ *
+ * <p>
+ * This call logically seals the transaction, which prevents the client from further changing the data tree using
+ * this transaction. Any subsequent calls to <code>put(LogicalDatastoreType, Path, Object)</code>,
+ * <code>merge(LogicalDatastoreType, Path, Object)</code>, <code>delete(LogicalDatastoreType, Path)</code> will fail
+ * with {@link IllegalStateException}. The transaction is marked as submitted and enqueued into the data store
+ * back-end for processing.
+ *
+ * <p>
+ * Whether or not the commit is successful is determined by versioning of the data tree and validation of registered
+ * commit participants if the transaction changes the data tree.
+ *
+ * <p>
+ * The effects of a successful commit of data depends on listeners and commit participants that are registered with
+ * the data broker.
+ *
+ * <p>
+ * <h3>Example usage:</h3>
+ * <pre>
+ * private void doWrite(final int tries) {
+ * WriteTransaction writeTx = dataBroker.newWriteOnlyTransaction();
+ * MyDataObject data = ...;
+ * InstanceIdentifier<MyDataObject> path = ...;
+ * writeTx.put(LogicalDatastoreType.OPERATIONAL, path, data);
+ * Futures.addCallback(writeTx.submit(), new FutureCallback<Void>() {
+ * public void onSuccess(Void result) {
+ * // succeeded
+ * }
+ * public void onFailure(Throwable t) {
+ * if(t instanceof OptimisticLockFailedException) {
+ * if(( tries - 1) > 0 ) {
+ * // do retry
+ * doWrite(tries - 1);
+ * } else {
+ * // out of retries
+ * }
+ * } else {
+ * // failed due to another type of TransactionCommitFailedException.
+ * }
+ * });
+ * }
+ * ...
+ * doWrite(2);
+ * </pre>
+ *
+ * <h2>Failure scenarios</h2>
+ *
+ * <p>
+ * Transaction may fail because of multiple reasons, such as
+ * <ul>
+ * <li>
+ * Another transaction finished earlier and modified the same node in a non-compatible way (see below). In this
+ * case the returned future will fail with an {@link OptimisticLockFailedException}. It is the responsibility
+ * of the caller to create a new transaction and submit the same modification again in order to update data
+ * tree.
+ * <i>
+ * <b>Warning</b>: In most cases, retrying after an OptimisticLockFailedException will result in a high
+ * probability of success. However, there are scenarios, albeit unusual, where any number of retries will
+ * not succeed. Therefore it is strongly recommended to limit the number of retries (2 or 3) to avoid
+ * an endless loop.
+ * </i>
+ * </li>
+ * <li>Data change introduced by this transaction did not pass validation by commit handlers or data was
+ * incorrectly structured. Returned future will fail with a {@link DataValidationFailedException}. User
+ * should not retry to create new transaction with same data, since it probably will fail again.
+ * </li>
+ * </ul>
+ *
+ * <h3>Change compatibility</h3>
+ * There are several sets of changes which could be considered incompatible between two transactions which are
+ * derived from same initial state. Rules for conflict detection applies recursively for each subtree level.
+ *
+ * <h4>Change compatibility of leafs, leaf-list items</h4>
+ * Following table shows state changes and failures between two concurrent transactions, which are based on same
+ * initial state, Tx 1 completes successfully before Tx 2 is submitted.
+ *
+ * <table summary="Change compatibility of leaf values">
+ * <tr>
+ * <th>Initial state</th>
+ * <th>Tx 1</th>
+ * <th>Tx 2</th>
+ * <th>Result</th>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(A,1)</td>
+ * <td>put(A,2)</td>
+ * <td>Tx 2 will fail, state is A=1</td>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(A,1)</td>
+ * <td>merge(A,2)</td>
+ * <td>A=2</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>Empty</td>
+ * <td>merge(A,1)</td>
+ * <td>put(A,2)</td>
+ * <td>Tx 2 will fail, state is A=1</td>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>merge(A,1)</td>
+ * <td>merge(A,2)</td>
+ * <td>A=2</td>
+ * </tr>
+ *
+ *
+ * <tr>
+ * <td>A=0</td>
+ * <td>put(A,1)</td>
+ * <td>put(A,2)</td>
+ * <td>Tx 2 will fail, A=1</td>
+ * </tr>
+ * <tr>
+ * <td>A=0</td>
+ * <td>put(A,1)</td>
+ * <td>merge(A,2)</td>
+ * <td>A=2</td>
+ * </tr>
+ * <tr>
+ * <td>A=0</td>
+ * <td>merge(A,1)</td>
+ * <td>put(A,2)</td>
+ * <td>Tx 2 will fail, A=1</td>
+ * </tr>
+ * <tr>
+ * <td>A=0</td>
+ * <td>merge(A,1)</td>
+ * <td>merge(A,2)</td>
+ * <td>A=2</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>A=0</td>
+ * <td>delete(A)</td>
+ * <td>put(A,2)</td>
+ * <td>Tx 2 will fail, A does not exists</td>
+ * </tr>
+ * <tr>
+ * <td>A=0</td>
+ * <td>delete(A)</td>
+ * <td>merge(A,2)</td>
+ * <td>A=2</td>
+ * </tr>
+ * </table>
+ *
+ * <h4>Change compatibility of subtrees</h4>
+ * Following table shows state changes and failures between two concurrent transactions, which are based on same
+ * initial state, Tx 1 completes successfully before Tx 2 is submitted.
+ *
+ * <table summary="Change compatibility of containers">
+ * <tr>
+ * <th>Initial state</th>
+ * <th>Tx 1</th>
+ * <th>Tx 2</th>
+ * <th>Result</th>
+ * </tr>
+ *
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(TOP,[])</td>
+ * <td>put(TOP,[])</td>
+ * <td>Tx 2 will fail, state is TOP=[]</td>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(TOP,[])</td>
+ * <td>merge(TOP,[])</td>
+ * <td>TOP=[]</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(TOP,[FOO=1])</td>
+ * <td>put(TOP,[BAR=1])</td>
+ * <td>Tx 2 will fail, state is TOP=[FOO=1]</td>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>put(TOP,[FOO=1])</td>
+ * <td>merge(TOP,[BAR=1])</td>
+ * <td>TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>Empty</td>
+ * <td>merge(TOP,[FOO=1])</td>
+ * <td>put(TOP,[BAR=1])</td>
+ * <td>Tx 2 will fail, state is TOP=[FOO=1]</td>
+ * </tr>
+ * <tr>
+ * <td>Empty</td>
+ * <td>merge(TOP,[FOO=1])</td>
+ * <td>merge(TOP,[BAR=1])</td>
+ * <td>TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>put(TOP,[FOO=1])</td>
+ * <td>put(TOP,[BAR=1])</td>
+ * <td>Tx 2 will fail, state is TOP=[FOO=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>put(TOP,[FOO=1])</td>
+ * <td>merge(TOP,[BAR=1])</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>merge(TOP,[FOO=1])</td>
+ * <td>put(TOP,[BAR=1])</td>
+ * <td>Tx 2 will fail, state is TOP=[FOO=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>merge(TOP,[FOO=1])</td>
+ * <td>merge(TOP,[BAR=1])</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>delete(TOP)</td>
+ * <td>put(TOP,[BAR=1])</td>
+ * <td>Tx 2 will fail, state is empty store</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>delete(TOP)</td>
+ * <td>merge(TOP,[BAR=1])</td>
+ * <td>state is TOP=[BAR=1]</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>put(TOP/FOO,1)</td>
+ * <td>put(TOP/BAR,1])</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>put(TOP/FOO,1)</td>
+ * <td>merge(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>merge(TOP/FOO,1)</td>
+ * <td>put(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>merge(TOP/FOO,1)</td>
+ * <td>merge(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=1,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>delete(TOP)</td>
+ * <td>put(TOP/BAR,1)</td>
+ * <td>Tx 2 will fail, state is empty store</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[]</td>
+ * <td>delete(TOP)</td>
+ * <td>merge(TOP/BAR,1]</td>
+ * <td>Tx 2 will fail, state is empty store</td>
+ * </tr>
+ *
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>put(TOP/FOO,2)</td>
+ * <td>put(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=2,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>put(TOP/FOO,2)</td>
+ * <td>merge(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=2,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>merge(TOP/FOO,2)</td>
+ * <td>put(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=2,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>merge(TOP/FOO,2)</td>
+ * <td>merge(TOP/BAR,1)</td>
+ * <td>state is TOP=[FOO=2,BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>delete(TOP/FOO)</td>
+ * <td>put(TOP/BAR,1)</td>
+ * <td>state is TOP=[BAR=1]</td>
+ * </tr>
+ * <tr>
+ * <td>TOP=[FOO=1]</td>
+ * <td>delete(TOP/FOO)</td>
+ * <td>merge(TOP/BAR,1]</td>
+ * <td>state is TOP=[BAR=1]</td>
+ * </tr>
+ * </table>
+ *
+ *
+ * <h3>Examples of failure scenarios</h3>
+ *
+ * <h4>Conflict of two transactions</h4>
+ * This example illustrates two concurrent transactions, which derived from same initial state
+ * of data tree and proposes conflicting modifications.
+ *
+ * <pre>
+ * txA = broker.newWriteTransaction(); // allocates new transaction, data tree is empty
+ * txB = broker.newWriteTransaction(); // allocates new transaction, data tree is empty
+ * txA.put(CONFIGURATION, PATH, A); // writes to PATH value A
+ * txB.put(CONFIGURATION, PATH, B) // writes to PATH value B
+ * ListenableFuture futureA = txA.submit(); // transaction A is sealed and submitted
+ * ListenebleFuture futureB = txB.submit(); // transaction B is sealed and submitted
+ * </pre>
+ * Commit of transaction A will be processed asynchronously and data tree will be updated to
+ * contain value <code>A</code> for <code>PATH</code>. Returned {@link ListenableFuture} will
+ * successfully complete once state is applied to data tree.
+ * Commit of Transaction B will fail, because previous transaction also modified path in a
+ * concurrent way. The state introduced by transaction B will not be applied. Returned
+ * {@link ListenableFuture} object will fail with {@link OptimisticLockFailedException}
+ * exception, which indicates to client that concurrent transaction prevented the submitted
+ * transaction from being applied. <br>
+ *
+ * <p>
+ * A successful commit produces implementation-specific {@link CommitInfo} structure, which is used to communicate
+ * post-condition information to the caller. Such information can contain commit-id, timing information or any
+ * other information the implementation wishes to share.
+ *
+ * @return a FluentFuture containing the result of the commit information. The Future blocks until the commit
+ * operation is complete. A successful commit returns nothing. On failure, the Future will fail with a
+ * {@link TransactionCommitFailedException} or an exception derived from TransactionCommitFailedException.
+ * @throws IllegalStateException if the transaction is already submitted or was canceled.
+ */
+ @CheckReturnValue
+ default @NonNull FluentFuture<? extends @NonNull CommitInfo> commit() {
+ return FluentFuture.from(submit()).transformAsync((ignored) -> CommitInfo.emptyFluentFuture(),
+ MoreExecutors.directExecutor());
+ }
}
Code Review / mdsal.git / commitdiff