Reworked DatabaseService API.
Initial implementation of LockManager.
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/ReadResult.java b/core/api/src/main/java/org/onlab/onos/store/service/ReadResult.java
index 49e9665..3f253f2 100644
--- a/core/api/src/main/java/org/onlab/onos/store/service/ReadResult.java
+++ b/core/api/src/main/java/org/onlab/onos/store/service/ReadResult.java
@@ -11,12 +11,21 @@
     private final String tableName;
     private final String key;
     private final VersionedValue value;
+    private final ReadStatus status;
 
-    public ReadResult(String tableName, String key, VersionedValue value) {
+    public ReadResult(ReadStatus status, String tableName, String key, VersionedValue value) {
+    	this.status = status;
         this.tableName = tableName;
         this.key = key;
         this.value = value;
     }
+    
+    /**
+     * Returns the status of the read operation.
+     */
+    public ReadStatus status() {
+    	return status;
+    }
 
     /**
      * Returns database table name.