Move AbstractDOMStoreTransaction into SPI
[controller.git] / opendaylight / md-sal / sal-inmemory-datastore / src / main / java / org / opendaylight / controller / md / sal / dom / store / impl / SnapshotBackedReadTransaction.java
index 39d6483c525ed648ea8c7f922ce8c57ee0064af0..8b18be432a4b42aa422526ca432596ecec68911c 100644 (file)
@@ -8,20 +8,19 @@
 package org.opendaylight.controller.md.sal.dom.store.impl;
 
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.base.Preconditions.checkState;
-
-import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.Futures;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.sal.core.spi.data.AbstractDOMStoreTransaction;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
-import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.ListenableFuture;
-
 /**
  *
  * Implementation of read-only transaction backed by {@link DataTreeSnapshot}
@@ -30,13 +29,14 @@ import com.google.common.util.concurrent.ListenableFuture;
  * which delegates most of its calls to similar methods provided by underlying snapshot.
  *
  */
-final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
-DOMStoreReadTransaction {
+final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction<Object>
+                                          implements DOMStoreReadTransaction {
+
     private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedReadTransaction.class);
-    private DataTreeSnapshot stableSnapshot;
+    private volatile DataTreeSnapshot stableSnapshot;
 
-    public SnapshotBackedReadTransaction(final Object identifier, final DataTreeSnapshot snapshot) {
-        super(identifier);
+    public SnapshotBackedReadTransaction(final Object identifier, final boolean debug, final DataTreeSnapshot snapshot) {
+        super(identifier, debug);
         this.stableSnapshot = Preconditions.checkNotNull(snapshot);
         LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot);
     }
@@ -48,9 +48,33 @@ DOMStoreReadTransaction {
     }
 
     @Override
-    public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final YangInstanceIdentifier path) {
+    public CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
+        LOG.debug("Tx: {} Read: {}", getIdentifier(), path);
         checkNotNull(path, "Path must not be null.");
-        checkState(stableSnapshot != null, "Transaction is closed");
-        return Futures.immediateFuture(stableSnapshot.readNode(path));
+
+        final DataTreeSnapshot snapshot = stableSnapshot;
+        if (snapshot == null) {
+            return Futures.immediateFailedCheckedFuture(new ReadFailedException("Transaction is closed"));
+        }
+
+        try {
+            return Futures.immediateCheckedFuture(snapshot.readNode(path));
+        } catch (Exception e) {
+            LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
+            return Futures.immediateFailedCheckedFuture(new ReadFailedException("Read failed",e));
+        }
+    }
+
+    @Override
+    public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
+        LOG.debug("Tx: {} Exists: {}", getIdentifier(), path);
+        checkNotNull(path, "Path must not be null.");
+
+        try {
+            return Futures.immediateCheckedFuture(
+                read(path).checkedGet().isPresent());
+        } catch (ReadFailedException e) {
+            return Futures.immediateFailedCheckedFuture(e);
+        }
     }
-}
\ No newline at end of file
+}