- * The initial state of the write transaction is stable snapshot of current data tree - * state captured when transaction was created and it's state and underlying - * data tree are not affected by other concurrently running transactions. - * - *
- * Write transactions are isolated from other concurrent write transactions. All - * writes are local to the transaction and represents only a proposal of state - * change for data tree and it is not visible to any other concurrently running - * transactions. - * - *
- * 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 #submit()} for more concrete commit failure examples. - * - * Implementation Note: This interface is not intended to be implemented - * by users of MD-SAL, but only to be consumed by them. - * - *
- * Let assume initial state of data tree for PATH is A
- * .
- *
- *
- * txWrite = broker.newReadWriteTransaction(); // concurrent write transaction - * - * txWrite.read(OPERATIONAL,PATH).get() // will return Optional containing A - * txWrite.put(OPERATIONAL,PATH,B); // writes B to PATH - * txWrite.read(OPERATIONAL,PATH).get() // will return Optional Containing B - * - * txWrite.commit().get(); // data tree is updated, PATH contains B - * - * tx1afterCommit = broker.newReadOnlyTransaction(); // read Transaction is snapshot of new state - * tx1afterCommit.read(OPERATIONAL,PATH).get(); // returns Optional containing B - *- * - *
- * As you could see read-write transaction provides capabilities as - * {@link AsyncWriteTransaction} but also allows for reading proposed changes as - * if they already happened. - * - *
PATH is A.
- *
- * - * txRead = broker.newReadOnlyTransaction(); // read Transaction is snapshot of data - * txWrite = broker.newReadWriteTransaction(); // concurrent write transaction - * - * txRead.read(OPERATIONAL,PATH).get(); // will return Optional containing A - * txWrite.read(OPERATIONAL,PATH).get() // will return Optional containing A - * - * txWrite.put(OPERATIONAL,PATH,B); // writes B to PATH - * txWrite.read(OPERATIONAL,PATH).get() // will return Optional Containing B - * - * txRead.read(OPERATIONAL,PATH).get(); // concurrent read transaction still returns - * // Optional containing A - * - * txWrite.commit().get(); // data tree is updated, PATH contains B - * txRead.read(OPERATIONAL,PATH).get(); // still returns Optional containing A - * - * tx1afterCommit = broker.newReadOnlyTransaction(); // read Transaction is snapshot of new state - * tx1afterCommit.read(OPERATIONAL,PATH).get(); // returns Optional containing B - *- * - *
PATH is A.
- *
- * - * tx1 = broker.newReadWriteTransaction(); // read Transaction is snapshot of data - * tx2 = broker.newReadWriteTransaction(); // concurrent write transaction - * - * tx1.read(OPERATIONAL,PATH).get(); // will return Optional containing A - * tx2.read(OPERATIONAL,PATH).get() // will return Optional containing A - * - * tx2.put(OPERATIONAL,PATH,B); // writes B to PATH - * tx2.read(OPERATIONAL,PATH).get() // will return Optional Containing B - * - * tx1.read(OPERATIONAL,PATH).get(); // tx1 read-write transaction still sees Optional - * // containing A since is isolated from tx2 - * tx1.put(OPERATIONAL,PATH,C); // writes C to PATH - * tx1.read(OPERATIONAL,PATH).get() // will return Optional Containing C - * - * tx2.read(OPERATIONAL,PATH).get() // tx2 read-write transaction still sees Optional - * // containing B since is isolated from tx1 - * - * tx2.commit().get(); // data tree is updated, PATH contains B - * tx1.read(OPERATIONAL,PATH).get(); // still returns Optional containing C since is isolated from tx2 - * - * tx1afterCommit = broker.newReadOnlyTransaction(); // read Transaction is snapshot of new state - * tx1afterCommit.read(OPERATIONAL,PATH).get(); // returns Optional containing B - * - * tx1.commit() // Will fail with OptimisticLockFailedException - * // which means concurrent transaction changed the same PATH - * - *- * - *
- * Note: examples contains blocking calls on future only to illustrate - * that action happened after other asynchronous action. Use of blocking call - * {@link com.google.common.util.concurrent.ListenableFuture#get()} is discouraged for most uses and you should - * use {@link com.google.common.util.concurrent.Futures#addCallback(com.google.common.util.concurrent.ListenableFuture, - * com.google.common.util.concurrent.FutureCallback, java.util.concurrent.Executor)} - * or other functions from {@link com.google.common.util.concurrent.Futures} to - * register more specific listeners. - * - * @see AsyncReadTransaction - * @see AsyncWriteTransaction - * - * @param
- * Type of path (subtree identifier), which represents location in
- * tree
- * @param , D> extends AsyncReadTransaction