Deprecate DCL in favor of DTCL

[controller.git] / opendaylight / md-sal / sal-binding-api / src / main / java / org / opendaylight / controller / md / sal / binding / api / ReadTransaction.java

diff --git a/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/md/sal/binding/api/ReadTransaction.java b/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/md/sal/binding/api/ReadTransaction.java
index a7b5f3295778c4f758e1c23785f3ef9fef9426bd..b0c93734e09dba7f964701f4875f10a6f69d297f 100644 (file)
--- a/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/md/sal/binding/api/ReadTransaction.java
+++ b/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/md/sal/binding/api/ReadTransaction.java
@@ -9,13 +9,42 @@ package org.opendaylight.controller.md.sal.binding.api;
 
 import org.opendaylight.controller.md.sal.common.api.data.AsyncReadTransaction;
 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
 import org.opendaylight.yangtools.yang.binding.DataObject;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
 import com.google.common.base.Optional;
-import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.CheckedFuture;
 
+/**
+ * A transaction that provides read access to a logical data store.
+ * <p>
+ * For more information on usage and examples, please see the documentation in {@link AsyncReadTransaction}.
+ */
 public interface ReadTransaction extends AsyncReadTransaction<InstanceIdentifier<?>, DataObject> {
-    @Override
-    ListenableFuture<Optional<DataObject>> read(LogicalDatastoreType store, InstanceIdentifier<?> path);
+
+    /**
+     * Reads data from the provided logical data store located at the provided path.
+     *<p>
+     * If the target is a subtree, then the whole subtree is read (and will be
+     * accessible from the returned data object).
+     *
+     * @param store
+     *            Logical data store from which read should occur.
+     * @param path
+     *            Path which uniquely identifies subtree which client want to
+     *            read
+     * @return a CheckFuture containing the result of the read. The Future blocks until the
+     *         commit operation is complete. Once complete:
+     *         <ul>
+     *         <li>If the data at the supplied path exists, the Future returns an Optional object
+     *         containing the data.</li>
+     *         <li>If the data at the supplied path does not exist, the Future returns
+     *         Optional#absent().</li>
+     *         <li>If the read of the data fails, the Future will fail with a
+     *         {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
+     *         </ul>
+     */
+    <T extends DataObject> CheckedFuture<Optional<T>,ReadFailedException> read(
+            LogicalDatastoreType store, InstanceIdentifier<T> path);
 }