* Write transactions are isolated from other concurrent write transactions. All * writes are local to the transaction and represent only a proposal of state * change for the data tree and it is not visible to any other concurrently running * transaction. + * + *
+ * Applications make changes to the local data tree in the transaction by via the + * put, merge, and delete operations. + * + *
+ * Performing the following put operations: + * + *
+ * 1) container { list [ a ] }
+ * 2) container { list [ b ] }
+ *
+ *
+ * + * will result in the following data being present: + * + *
+ * container { list [ b ] }
+ *
+ * + * Performing the following merge operations: + * + *
+ * 1) container { list [ a ] }
+ * 2) container { list [ b ] }
+ *
+ *
+ * + * will result in the following data being present: + * + *
+ * container { list [ a, b ] }
+ *
+ *
+ * + * This also means that storing the container will preserve any + * augmentations which have been attached to it. + * + *
- * Applications publish the changes proposed in the transaction by calling {@link #commit} - * on the transaction. This seals the transaction + * After applying changes to the local data tree, applications publish the changes proposed in the + * transaction by calling {@link #submit} on the transaction. This seals the transaction * (preventing any further writes using this transaction) and submits it to be * processed and applied to global conceptual data tree. + * *
* The transaction commit may fail due to a concurrent transaction modifying and committing data in - * an incompatible way. See {@link #commit()} for more concrete commit failure examples. - * + * an incompatible way. See {@link #submit} for more concrete commit failure examples. * *
* Implementation Note: This interface is not intended to be implemented
@@ -45,150 +101,122 @@ import com.google.common.util.concurrent.ListenableFuture;
* @param , D> extends AsyncTransaction
+ * Transactions can only be cancelled if it's state is new or submitted.
*
- * Invoking cancel() on {@link TransactionStatus#FAILED} or
- * {@link TransactionStatus#CANCELED} will have no effect, and transaction
+ *
+ * Invoking cancel() on a failed or cancelled transaction will have no effect, and transaction
* is considered cancelled.
*
- * Invoking cancel() on finished transaction (future returned by {@link #commit()}
- * already completed with {@link TransactionStatus#COMMITED}) will always
+ *
+ * Invoking cancel() on a finished transaction (future returned by {@link #submit()} already completed will always
* fail (return false).
*
- * @return false if the task could not be cancelled,
- * typically because it has already completed normally;
- * true otherwise
+ * @return {@code false} if the task could not be cancelled, typically because it has already completed normally
+ * {@code true} otherwise
*
*/
- public boolean cancel();
+ boolean cancel();
/**
- * Store a piece of data at specified path. This acts as an add / replace
- * operation, which is to say that whole subtree will be replaced by
- * specified path. Performing the following put operations:
- *
- *
- * If you require an explicit replace operation, use
- * {@link #put(LogicalDatastoreType, Path, Object)} instead.
+ * Submits this transaction to be asynchronously applied to update the logical data tree.
+ * The returned CheckedFuture conveys the result of applying the data changes.
*
- * @param store
- * Logical data store which should be modified
- * @param path
- * Data object path
- * @param data
- * Data object to be written to specified path
- * @throws IllegalStateException
- * if the transaction is no longer {@link TransactionStatus#NEW}
- */
- public void merge(LogicalDatastoreType store, P path, D data);
-
- /**
- * Remove a piece of data from specified path. This operation does not fail
- * if the specified path does not exist.
+ *
+ * Note: It is strongly recommended to process the CheckedFuture result in an asynchronous
+ * manner rather than using the blocking get() method. See example usage below.
*
- * @param store
- * Logical data store which should be modified
- * @param path
- * Data object path
- * @throws IllegalStateException
- * if the transaction is no longer {@link TransactionStatus#NEW}
- */
- public void delete(LogicalDatastoreType store, P path);
-
- /**
- * Submits transaction to be applied to update logical data tree.
*
* This call logically seals the transaction, which prevents the client from
* further changing data tree using this transaction. Any subsequent calls to
- * {@link #put(LogicalDatastoreType, Path, Object)},
- * {@link #merge(LogicalDatastoreType, Path, Object)} or
* {@link #delete(LogicalDatastoreType, Path)} will fail with
* {@link IllegalStateException}.
*
- * The transaction is marked as {@link TransactionStatus#SUBMITED} and
- * enqueued into the data store backed for processing.
+ *
+ * The transaction is marked as submitted and enqueued into the data store back-end for processing.
*
*
* Whether or not the commit is successful is determined by versioning
- * of data tree and validation of registered commit participants
- * {@link AsyncConfigurationCommitHandler}
- * if transaction changes {@link LogicalDatastoreType#CONFIGURATION} data tree.
- *
- * The effects of successful commit of data depends on
- * other data change listeners {@link AsyncDataChangeListener} and
- * {@link AsyncConfigurationCommitHandler}, which was registered to the
- * same {@link AsyncDataBroker}, to which this transaction belongs.
+ * of the data tree and validation of registered commit participants
+ * ({@link AsyncConfigurationCommitHandler}) if the transaction changes the data tree.
+ *
+ *
+ * The effects of a successful commit of data depends on data tree change listeners and commit participants
+ * ({@link AsyncConfigurationCommitHandler}) that are registered with the data broker.
*
+ *
* Transaction may fail because of multiple reasons, such as
*
* 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
@@ -196,11 +224,13 @@ public interface AsyncWriteTransaction , D> extends AsyncTransa
*
*
* 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.
*
* , D> extends AsyncTransa
*
*
* 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.
*
* , D> extends AsyncTransa
* , D> extends AsyncTransa
*
*
* This example illustrates two concurrent transactions, which derived from
* same initial state of data tree and proposes conflicting modifications.
*
@@ -273,34 +313,79 @@ public interface AsyncWriteTransaction , D> extends AsyncTransa
* txA.put(CONFIGURATION, PATH, A); // writes to PATH value A
* txB.put(CONFIGURATION, PATH, B) // writes to PATH value B
*
- * ListenableFuture futureA = txA.commit(); // transaction A is sealed and committed
- * ListenebleFuture futureB = txB.commit(); // transaction B is sealed and committed
+ * ListenableFuture futureA = txA.submit(); // transaction A is sealed and submitted
+ * ListenebleFuture futureB = txB.submit(); // transaction B is sealed and submitted
*
*
+ *
* Commit of transaction A will be processed asynchronously and data tree
* will be updated to contain value
* 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.
- *
- * @return Result of the Commit, containing success information or list of
- * encountered errors, if commit was not successful. The Future
- * blocks until {@link TransactionStatus#COMMITED} is reached.
- * Future will fail with {@link TransactionCommitFailedException} if
- * Commit of this transaction failed. TODO: Usability: Consider
- * change from ListenableFuture to
- * {@link com.google.common.util.concurrent.CheckedFuture} which
- * will throw {@link TransactionCommitFailedException}.
+ *
+ * This call logically seals the transaction, which prevents the client from further changing the data tree using
+ * this transaction. Any subsequent calls to
+ * 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.
+ *
+ *
+ * The effects of a successful commit of data depends on listeners and commit participants that are registered with
+ * the data broker.
+ *
+ *
+ * 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 committed or was canceled.
*/
- public ListenableFuture
- * 1) container { list [ a ] }
- * 2) container { list [ b ] }
- *
- *
- * will result in the following data being present:
- *
- *
- * container { list [ b ] }
- *
- *
- *
- * If you need to make sure that a parent object exists, but you do not want modify
- * its preexisting state by using put, consider using
- * {@link #merge(LogicalDatastoreType, Path, Object)}
+ * Removes a piece of data from specified path. This operation does not fail
+ * if the specified path does not exist.
*
* @param store
* Logical data store which should be modified
* @param path
* Data object path
- * @param data
- * Data object to be written to specified path
* @throws IllegalStateException
- * if the transaction is no longer {@link TransactionStatus#NEW}
+ * if the transaction as already been submitted or cancelled
*/
- public void put(LogicalDatastoreType store, P path, D data);
+ void delete(LogicalDatastoreType store, P path);
/**
- * Store a piece of data at the specified path. This acts as a merge operation,
- * which is to say that any pre-existing data which is not explicitly
- * overwritten will be preserved. This means that if you store a container,
- * its child lists will be merged. Performing the following merge
- * operations:
- *
- *
- * 1) container { list [ a ] }
- * 2) container { list [ b ] }
- *
- *
- * will result in the following data being present:
- *
- *
- * container { list [ a, b ] }
- *
- *
- * This also means that storing the container will preserve any
- * augmentations which have been attached to it.
- *Example usage:
+ *
+ * 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 );
+ *
* Failure scenarios
+ *
*
- *
*
* Change compatibility
*
+ * Change compatibility of leafs, leaf-list items
*
+ *
+ *
Initial state Tx 1 Tx 2 Result Empty put(A,1) put(A,2) Tx 2 will fail, state is A=1 Empty put(A,1) merge(A,2) A=2 Change compatibility of subtrees
*
+ *
+ *
@@ -263,6 +302,7 @@ public interface AsyncWriteTransactionInitial state Tx 1 Tx 2 Result Empty put(TOP,[]) put(TOP,[]) Tx 2 will fail, state is TOP=[] Empty put(TOP,[]) merge(TOP,[]) TOP=[] Empty put(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1] Empty put(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1]
+ * Empty put(TOP,[FOO=1]) merge(TOP,[BAR=1]) TOP=[FOO=1,BAR=1] Empty merge(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1] Empty merge(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1]
+ * Empty merge(TOP,[FOO=1]) merge(TOP,[BAR=1]) TOP=[FOO=1,BAR=1] TOP=[] put(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1] TOP=[] put(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1]
+ * TOP=[] put(TOP,[FOO=1]) merge(TOP,[BAR=1]) state is TOP=[FOO=1,BAR=1] TOP=[] merge(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1] TOP=[] merge(TOP,[FOO=1]) put(TOP,[BAR=1]) Tx 2 will fail, state is TOP=[FOO=1]
+ * TOP=[] merge(TOP,[FOO=1]) merge(TOP,[BAR=1]) state is TOP=[FOO=1,BAR=1] TOP=[] delete(TOP) put(TOP,[BAR=1]) Tx 2 will fail, state is empty store TOP=[] delete(TOP) put(TOP,[BAR=1]) Tx 2 will fail, state is empty store
+ * TOP=[] delete(TOP) merge(TOP,[BAR=1]) state is TOP=[BAR=1] TOP=[] put(TOP/FOO,1) put(TOP/BAR,1]) state is TOP=[FOO=1,BAR=1] TOP=[] merge(TOP/FOO,1) put(TOP/BAR,1) state is TOP=[FOO=1,BAR=1] TOP=[] merge(TOP/FOO,1) merge(TOP/BAR,1) state is TOP=[FOO=1,BAR=1] TOP=[] delete(TOP) put(TOP/BAR,1) Tx 2 will fail, state is empty store TOP=[] delete(TOP) merge(TOP/BAR,1] Tx 2 will fail, state is empty store TOP=[] delete(TOP) merge(TOP/BAR,1] Tx 2 will fail, state is empty store
+ * TOP=[FOO=1] put(TOP/FOO,2) put(TOP/BAR,1) state is TOP=[FOO=2,BAR=1] TOP=[FOO=1] put(TOP/FOO,2) merge(TOP/BAR,1) state is TOP=[FOO=2,BAR=1] TOP=[FOO=1] merge(TOP/FOO,2) put(TOP/BAR,1) state is TOP=[FOO=2,BAR=1] TOP=[FOO=1] merge(TOP/FOO,2) merge(TOP/BAR,1) state is TOP=[FOO=2,BAR=1] TOP=[FOO=1] merge(TOP/FOO,2) merge(TOP/BAR,1) state is TOP=[FOO=2,BAR=1]
+ * TOP=[FOO=1] delete(TOP/FOO) put(TOP/BAR,1) state is TOP=[BAR=1] TOP=[FOO=1] delete(TOP/FOO) merge(TOP/BAR,1] state is TOP=[BAR=1] Conflict of two transactions
*
+ * A for PATH.
* Returned {@link ListenableFuture} will successfully complete once
* state is applied to data tree.
*
+ *
+ * @return a CheckFuture containing the result of the commit. 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 not {@link TransactionStatus#NEW}
+ * if the transaction is not new
+ * @deprecated Use {@link #commit()} instead.
+ */
+ @Deprecated
+ default CheckedFutureput(LogicalDatastoreType, Path, Object),
+ * merge(LogicalDatastoreType, Path, Object), delete(LogicalDatastoreType, Path) will fail
+ * with {@link IllegalStateException}. The transaction is marked as submitted and enqueued into the data store
+ * back-end for processing.
+ *
+ *