Yet another fix for javadoc

[mdsal.git] / binding / mdsal-binding-api / src / main / java / org / opendaylight / mdsal / binding / api / TransactionFactory.java

diff --git a/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/TransactionFactory.java b/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/TransactionFactory.java
index b41e7be9e68319490cdf2f153e73e57bd93ee4be..be2eeb0943a2a80458e4e88d467dc09f9d7c8c8c 100644 (file)
--- a/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/TransactionFactory.java
+++ b/binding/mdsal-binding-api/src/main/java/org/opendaylight/mdsal/binding/api/TransactionFactory.java
@@ -7,17 +7,88 @@
  */
 package org.opendaylight.mdsal.binding.api;
 
-import org.opendaylight.mdsal.common.api.AsyncDataTransactionFactory;
-import org.opendaylight.yangtools.yang.binding.DataObject;
-import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.eclipse.jdt.annotation.NonNull;
 
-public interface TransactionFactory extends AsyncDataTransactionFactory<InstanceIdentifier<?>, DataObject> {
-    @Override
-    ReadTransaction newReadOnlyTransaction();
+/**
+ * A factory which allocates new transactions to operate on the data tree.
+ *
+ * <p>
+ * <b>Note:</b> This interface is not intended to be used directly, but rather via subinterfaces
+ * which introduces additional semantics to allocated transactions.
+ * <ul>
+ * <li> {@link DataBroker}
+ * <li> {@link TransactionChain}
+ * </ul>
+ *
+ * <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 provides a stable isolated view of the data tree, which is guaranteed to be
+ * not affected by other concurrent transactions, until transaction is committed.
+ *
+ * <p>
+ * For a detailed explanation of how transaction are isolated and how transaction-local changes are
+ * committed to global data tree, see {@link ReadTransaction}, {@link WriteTransaction}
+ * and {@link WriteTransaction#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.
+ *
+ * @see DataBroker
+*/
+public interface TransactionFactory {
+    /**
+     * Allocates a new read-only transaction which provides an immutable snapshot of the data tree. The view of data
+     * tree is an immutable snapshot of current data tree state when transaction was allocated.
+     *
+     * @return A new read-only transaction
+     */
+    @NonNull ReadTransaction newReadOnlyTransaction();
 
-    @Override
-    ReadWriteTransaction newReadWriteTransaction();
+    /**
+     * Allocates new read-write transaction which provides a mutable view of the data tree.
+     *
+     * <p>
+     * Preconditions for mutation of data tree are captured from the snapshot of data tree state, when the transaction
+     * is allocated. If data was changed during transaction in an incompatible way then the commit of this transaction
+     * will fail. See {@link ReadWriteTransaction#commit()} for more details about conflicting and non-conflicting
+     * changes and failure scenarios.
+     *
+     * @return new read-write transaction
+     */
+    @NonNull ReadWriteTransaction newReadWriteTransaction();
 
-    @Override
-    WriteTransaction newWriteOnlyTransaction();
+    /**
+     * Allocates new write-only transaction based on latest state of data tree.
+     *
+     * <p>
+     * Preconditions for mutation of data tree are captured from the snapshot of data tree state, when the transaction
+     * is allocated. If data was changed during transaction in an incompatible way then the commit of this transaction
+     * will fail. See {@link WriteTransaction#commit()} for more details about conflicting and not-conflicting changes
+     * and failure scenarios.
+     *
+     * <p>
+     * Since this transaction does not provide a view of the data it SHOULD BE used only by callers who are exclusive
+     * writers (exporters of data) to the subtree they modify. This prevents optimistic lock failures as described in
+     * {@link WriteTransaction#commit()}.
+     *
+     * <p>
+     * Exclusivity of writers to particular subtree SHOULD BE enforced by external locking mechanism.
+     *
+     * @return new write-only transaction
+     */
+    @NonNull WriteTransaction newWriteOnlyTransaction();
 }