Fixup "Leader should always apply modifications as local" regression

[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / persisted / CommitTransactionPayload.java

diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/persisted/CommitTransactionPayload.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/persisted/CommitTransactionPayload.java
index f4ac854a2c6e1ac6d98d6bed7326429a4c7bcb14..65a65ea620120bb0e37f0b29c1969b5af2b400de 100644 (file)
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/persisted/CommitTransactionPayload.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/persisted/CommitTransactionPayload.java
@@ -29,7 +29,7 @@ import java.util.Map.Entry;
 import org.eclipse.jdt.annotation.NonNull;
 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
 import org.opendaylight.controller.cluster.datastore.persisted.DataTreeCandidateInputOutput.DataTreeCandidateWithVersion;
-import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
+import org.opendaylight.controller.cluster.raft.protobuff.client.messages.IdentifiablePayload;
 import org.opendaylight.yangtools.concepts.Variant;
 import org.opendaylight.yangtools.yang.data.api.schema.stream.ReusableStreamReceiver;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
@@ -44,10 +44,13 @@ import org.slf4j.LoggerFactory;
  * @author Robert Varga
  */
 @Beta
-public abstract class CommitTransactionPayload extends Payload implements Serializable {
+public abstract class CommitTransactionPayload extends IdentifiablePayload<TransactionIdentifier>
+        implements Serializable {
     private static final Logger LOG = LoggerFactory.getLogger(CommitTransactionPayload.class);
     private static final long serialVersionUID = 1L;
 
+    private volatile Entry<TransactionIdentifier, DataTreeCandidateWithVersion> candidate = null;
+
     CommitTransactionPayload() {
 
     }
@@ -79,7 +82,16 @@ public abstract class CommitTransactionPayload extends Payload implements Serial
     }
 
     public @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate() throws IOException {
-        return getCandidate(ReusableImmutableNormalizedNodeStreamWriter.create());
+        Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = candidate;
+        if (localCandidate == null) {
+            synchronized (this) {
+                localCandidate = candidate;
+                if (localCandidate == null) {
+                    candidate = localCandidate = getCandidate(ReusableImmutableNormalizedNodeStreamWriter.create());
+                }
+            }
+        }
+        return localCandidate;
     }
 
     public final @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate(
@@ -89,6 +101,26 @@ public abstract class CommitTransactionPayload extends Payload implements Serial
                 DataTreeCandidateInputOutput.readDataTreeCandidate(in, receiver));
     }
 
+    @Override
+    public TransactionIdentifier getIdentifier() {
+        try  {
+            return getCandidate().getKey();
+        } catch (IOException e) {
+            throw new IllegalStateException("Candidate deserialization failed.", e);
+        }
+    }
+
+    /**
+     * The cached candidate needs to be cleared after it is done applying to the DataTree, otherwise it would be keeping
+     * deserialized in memory which are not needed anymore leading to wasted memory. This lets the payload know that
+     * this was the last time the candidate was needed ant it is safe to be cleared.
+     */
+    public Entry<TransactionIdentifier, DataTreeCandidateWithVersion> acquireCandidate() throws IOException {
+        final Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = getCandidate();
+        candidate = null;
+        return localCandidate;
+    }
+
     abstract void writeBytes(ObjectOutput out) throws IOException;
 
     abstract DataInput newDataInput();