X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-dom-spi%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fsal%2Fcore%2Fspi%2Fdata%2FDOMStoreReadTransaction.java;h=306891189a6d7f0f5b0745c9de0e63362fff768c;hp=733c10926cce352ccfbe79168a22e92776a7c8ae;hb=206d37a9d8ac56b38e754da6ed3d09a60f1fea56;hpb=11de48616ef1104c24e04e6ca837956651e5f979

diff --git a/opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/DOMStoreReadTransaction.java b/opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/DOMStoreReadTransaction.java
index 733c10926c..306891189a 100644
--- a/opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/DOMStoreReadTransaction.java
+++ b/opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/DOMStoreReadTransaction.java
@@ -7,31 +7,53 @@
  */
 package org.opendaylight.controller.sal.core.spi.data;
 
-import java.util.concurrent.Future;
-
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+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;
 
 public interface DOMStoreReadTransaction extends DOMStoreTransaction {
 
     /**
-     *
      * Reads data from provided logical data store located at provided path
      *
-     *
      * @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 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>
+     */
+    CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(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 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 data at supplied path exists the {@link Future#get()}
-     *         returns Optional object containing data
-     *         <li>If data at supplied path does not exists the
-     *         {@link Future#get()} returns {@link Optional#absent()}.
+     *         <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>
      */
-    ListenableFuture<Optional<NormalizedNode<?,?>>> read(InstanceIdentifier path);
+    CheckedFuture<Boolean, ReadFailedException> exists(YangInstanceIdentifier path);
 }