+++ /dev/null
-/*
- * Copyright (c) 2017 Pantheon Technologies s.r.o. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * 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.binding.javav2.api;
-
-import com.google.common.annotations.Beta;
-import com.google.common.util.concurrent.FluentFuture;
-import javax.annotation.CheckReturnValue;
-import org.eclipse.jdt.annotation.NonNull;
-import org.opendaylight.mdsal.binding.javav2.spec.base.InstanceIdentifier;
-import org.opendaylight.mdsal.binding.javav2.spec.base.TreeNode;
-import org.opendaylight.mdsal.common.api.CommitInfo;
-import org.opendaylight.mdsal.common.api.DataValidationFailedException;
-import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
-import org.opendaylight.mdsal.common.api.OptimisticLockFailedException;
-import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
-
-/**
- * A transaction that provides mutation capabilities on a data tree.
- *
- * <p>
- * Initial state of write transaction is a stable snapshot of the current data tree. The state is captured when
- * the transaction is created and its state and underlying data tree are not affected by other concurrently running
- * transactions.
- *
- * <p>
- * 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.
- *
- * <p>
- * Applications make changes to the local data tree in the transaction by via the <b>put</b>, <b>merge</b>,
- * and <b>delete</b> operations.
- *
- * <h2>Put operation</h2>
- * Stores a piece of data at a specified path. This acts as an add / replace operation, which is to say that whole
- * subtree will be replaced by the specified data.
- *
- * <p>
- * Performing the following put operations:
- *
- * <pre>
- * 1) container { list [ a ] }
- * 2) container { list [ b ] }
- * </pre>
- * will result in the following data being present:
- *
- * <pre>
- * container { list [ b ] }
- * </pre>
- * <h2>Merge operation</h2>
- * Merges a piece of data with the existing data at a specified path. 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.
- *
- * <p>
- * Performing the following merge operations:
- *
- * <pre>
- * 1) container { list [ a ] }
- * 2) container { list [ b ] }
- * </pre>
- * will result in the following data being present:
- *
- * <pre>
- * container { list [ a, b ] }
- * </pre>
- * This also means that storing the container will preserve any augmentations which have been attached to it.
- *
- * <h2>Delete operation</h2>
- * Removes a piece of data from a specified path.
- *
- * <p>
- * After applying changes to the local data tree, applications publish the changes proposed in the transaction
- * by calling {@link #commit} on the transaction. This seals the transaction (preventing any further writes using this
- * transaction) and commits it to be processed and applied to global conceptual data tree.
- *
- * <p>
- * 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.
- *
- * <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.
- */
-@Beta
-public interface WriteTransaction extends Transaction {
- /**
- * Cancels the transaction. Transactions can only be cancelled if it was not yet committed.
- * Invoking cancel() on failed or already canceled will have no effect, and transaction is considered cancelled.
- * Invoking cancel() on finished transaction (future returned by {@link #commit()} already successfully completed)
- * will always fail (return false).
- *
- * @return <tt>false</tt> if the task could not be cancelled, typically because it has already completed normally;
- * <tt>true</tt> otherwise
- */
- boolean cancel();
-
- /**
- * Commits 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 committed 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.
- *
- * <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.commit(), new FutureCallback<CommitInfo>() {
- * public void onSuccess(CommitInfo 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 commit 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 committed.
- *
- * <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 committed.
- *
- * <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.commit(); // transaction A is sealed and committed
- * ListenebleFuture futureB = txB.commit(); // transaction B is sealed and committed
- * </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 FluentFuture} 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 FluentFuture} object will fail with {@link OptimisticLockFailedException}
- * exception, which indicates to client that concurrent transaction prevented the committed
- * 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 committed or was canceled.
- */
- @CheckReturnValue
- @NonNull FluentFuture<? extends @NonNull CommitInfo> commit();
-
- /**
- * Stores a piece of data at the specified path. This acts as an add / replace
- * operation, which is to say that whole subtree will be replaced by the specified data.
- *
- * <p>
- * This method does not automatically create missing parent nodes. It is equivalent to invoking
- * {@link #put(LogicalDatastoreType, InstanceIdentifier, TreeNode, boolean)}
- * with <code>createMissingParents</code> set to false.
- *
- * <p>
- * If you need to make sure that a parent object exists but you do not want modify
- * its pre-existing state by using put, consider using {@link #merge} instead.
- *
- * @param store
- * the logical data store which should be modified
- * @param path
- * the data object path
- * @param data
- * the data object to be written to the specified path
- * @param <T> data tree type
- * @throws IllegalStateException
- * if the transaction has already been submitted
- */
- <T extends TreeNode> void put(LogicalDatastoreType store, InstanceIdentifier<T> path, T data);
-
- /**
- * Stores a piece of data at the specified path. This acts as an add / replace operation, which is to say that whole
- * subtree will be replaced by the specified data.
- *
- * <p>
- * If you need to make sure that a parent object exists but you do not want modify its pre-existing state by using
- * put, consider using {@link #merge} instead.
- *
- * <p>
- * Note: Using <code>createMissingParents</code> with value true, may
- * introduce garbage in data store, or recreate nodes, which were deleted by
- * previous transaction.
- *
- * @param store
- * the logical data store which should be modified
- * @param path
- * the data object path
- * @param data
- * the data object to be written to the specified path
- * @param createMissingParents
- * if {@link #CREATE_MISSING_PARENTS}, any missing parent nodes will be automatically
- * created using a merge operation.
- * @param <T> data tree type
- * @throws IllegalStateException
- * if the transaction has already been submitted
- */
- <T extends TreeNode> void put(LogicalDatastoreType store, InstanceIdentifier<T> path, T data,
- boolean createMissingParents);
-
- /**
- * Merges a piece of data with the existing data at a specified path. 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.
- *
- * <p>
- * This method does not automatically create missing parent nodes. It is equivalent to invoking
- * {@link #merge(LogicalDatastoreType, InstanceIdentifier, TreeNode, boolean)}
- * with <code>createMissingParents</code> set to false.
- *
- * <p>
- * If you require an explicit replace operation, use {@link #put} instead.
- * @param store the logical data store which should be modified
- * @param path the data object path
- * @param data the data object to be merged to the specified path
- * @param <T> data tree type
- * @throws IllegalStateException if the transaction has already been submitted
- */
- <T extends TreeNode> void merge(LogicalDatastoreType store, InstanceIdentifier<T> path, T data);
-
- /**
- * Merges a piece of data with the existing data at a specified path. 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.
- *
- * <p>
- * If you require an explicit replace operation, use {@link #put} instead.
- *
- * @param store the logical data store which should be modified
- * @param path the data object path
- * @param data the data object to be merged to the specified path
- * @param createMissingParents if {@link #CREATE_MISSING_PARENTS}, any missing parent nodes will be automatically
- * created using a merge operation.
- * @param <T> data tree type
- * @throws IllegalStateException if the transaction has already been submitted
- */
- <T extends TreeNode> void merge(LogicalDatastoreType store, InstanceIdentifier<T> path, T data,
- boolean createMissingParents);
-
- /**
- * 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
- * @throws IllegalStateException if the transaction was committed or canceled.
- */
- void delete(LogicalDatastoreType store, InstanceIdentifier<?> path);
-
- /**
- * Flag value indicating that missing parents should be created.
- */
- boolean CREATE_MISSING_PARENTS = true;
-
- /**
- * Flag value indicating that missing parents should cause an error.
- */
- boolean FAIL_ON_MISSING_PARENTS = false;
-}
Code Review / mdsal.git / blobdiff