Improve log compaction efficiency in AtomixConsistentMap.

Change-Id: I0d78df3e00e8253c9015504be77f026512bb4d08
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapCommands.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapCommands.java
index b83aa52..e64bbbf 100644
--- a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapCommands.java
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapCommands.java
@@ -250,6 +250,11 @@
         public TransactionPrepareAndCommit(MapTransaction<String, byte[]> mapTransaction) {
             super(mapTransaction);
         }
+
+        @Override
+        public CompactionMode compaction() {
+            return CompactionMode.QUORUM;
+        }
     }
 
     /**
@@ -287,6 +292,11 @@
         }
 
         @Override
+        public CompactionMode compaction() {
+            return CompactionMode.TOMBSTONE;
+        }
+
+        @Override
         public String toString() {
             return MoreObjects.toStringHelper(getClass())
                     .add("transactionId", transactionId)
@@ -329,6 +339,11 @@
         }
 
         @Override
+        public CompactionMode compaction() {
+            return CompactionMode.TOMBSTONE;
+        }
+
+        @Override
         public String toString() {
             return MoreObjects.toStringHelper(getClass())
                     .add("transactionId", transactionId)
@@ -393,7 +408,7 @@
 
         @Override
         public CompactionMode compaction() {
-          return value == null ? CompactionMode.FULL : CompactionMode.QUORUM;
+          return value == null ? CompactionMode.TOMBSTONE : CompactionMode.QUORUM;
         }
 
         @Override
@@ -478,10 +493,9 @@
      */
     @SuppressWarnings("serial")
     public static class Clear extends MapCommand<MapEntryUpdateResult.Status> {
-
         @Override
         public CompactionMode compaction() {
-          return CompactionMode.FULL;
+          return CompactionMode.TOMBSTONE;
         }
     }
 
@@ -497,6 +511,11 @@
         @Override
         public void readObject(BufferInput<?> buffer, Serializer serializer) {
         }
+
+        @Override
+        public CompactionMode compaction() {
+            return CompactionMode.QUORUM;
+        }
     }
 
     /**
@@ -511,6 +530,11 @@
         @Override
         public void readObject(BufferInput<?> buffer, Serializer serializer) {
         }
+
+        @Override
+        public CompactionMode compaction() {
+            return CompactionMode.TOMBSTONE;
+        }
     }
 
     /**
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapState.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapState.java
index 50db768..84cd53a 100644
--- a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapState.java
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapState.java
@@ -401,7 +401,7 @@
                     }
                 }
             }
-            // No violations detected. Add to pendingTranctions and mark
+            // No violations detected. Add to pendingTransactions and mark
             // modified keys as locked for updates.
             pendingTransactions.put(transaction.transactionId(), commit);
             transaction.updates().forEach(u -> preparedKeys.add(u.key()));