X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-dom-api%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fmd%2Fsal%2Fdom%2Fapi%2FDOMDataReadTransaction.java;h=05ca61a3535699273ed4ca0e169a9fcbd9dc88b7;hp=afa2286d53d94d4af669af7ba2c542221961372c;hb=206d37a9d8ac56b38e754da6ed3d09a60f1fea56;hpb=11e9ade9af527aba7faeb633d3c9c7552fd09d2d

diff --git a/opendaylight/md-sal/sal-dom-api/src/main/java/org/opendaylight/controller/md/sal/dom/api/DOMDataReadTransaction.java b/opendaylight/md-sal/sal-dom-api/src/main/java/org/opendaylight/controller/md/sal/dom/api/DOMDataReadTransaction.java
index afa2286d53..05ca61a353 100644
--- a/opendaylight/md-sal/sal-dom-api/src/main/java/org/opendaylight/controller/md/sal/dom/api/DOMDataReadTransaction.java
+++ b/opendaylight/md-sal/sal-dom-api/src/main/java/org/opendaylight/controller/md/sal/dom/api/DOMDataReadTransaction.java
@@ -9,11 +9,12 @@ package org.opendaylight.controller.md.sal.dom.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.data.api.YangInstanceIdentifier;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
 
 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.
@@ -33,14 +34,44 @@ public interface DOMDataReadTransaction extends AsyncReadTransaction<YangInstanc
      * @param path
      *            Path which uniquely identifies subtree which client want to
      *            read
-     * @return Listenable Future which contains read result
+     * @return a CheckFuture containing the result of the read. The Future blocks until the
+     *         commit operation is complete. Once complete:
      *         <ul>
-     *         <li>If data at supplied path exists the
-     *         {@link ListeblaFuture#get()} returns Optional object containing
-     *         data once read is done.
-     *         <li>If data at supplied path does not exists the
-     *         {@link ListenbleFuture#get()} returns {@link Optional#absent()}.
+     *         <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>
      */
-    ListenableFuture<Optional<NormalizedNode<?,?>>> read(LogicalDatastoreType store,YangInstanceIdentifier path);
+    CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(
+            LogicalDatastoreType store, YangInstanceIdentifier path);
+
+    /**
+     /**
+     * Checks if data is available in the logical data store located at provided path.
+     * <p>
+     *
+     * Note: a successful result from this method makes no guarantee that a subsequent call to {@link #read}
+     * will succeed. It is possible that the data resides in a data store on a remote node and, if that
+     * node goes down or a network failure occurs, a subsequent read would fail. Another scenario is if
+     * the data is deleted in between the calls to <code>exists</code> and <code>read</code>
+     *
+     * @param store
+     *            Logical data store from which read should occur.
+     * @param path
+     *            Path which uniquely identifies subtree which client want to
+     *            check existence of
+     * @return a CheckFuture containing the result of the check.
+     *         <ul>
+     *         <li>If the data at the supplied path exists, the Future returns a Boolean
+     *         whose value is true, false otherwise</li>
+     *         <li>If checking for the data fails, the Future will fail with a
+     *         {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
+     *         </ul>
+     */
+    CheckedFuture<Boolean, ReadFailedException> exists(
+        LogicalDatastoreType store, YangInstanceIdentifier path);
+
 }