Add initialize() and clearAllData() APIs for MetaStore

cassandra/src/main/scala/filodb.cassandra/metastore/CassandraMetaStore.scala

@@ -8,10 +8,19 @@ import filodb.core.metadata.{Column, Dataset, MetaStore}
 
 class CassandraMetaStore(config: Config)
                         (implicit val ec: ExecutionContext) extends MetaStore {
-
   val datasetTable = DatasetTable
   val columnTable = ColumnTable
 
+  def initialize(): Future[Response] =
+    for { dtResp <- datasetTable.initialize()
+          ctResp <- columnTable.initialize() }
+    yield { ctResp }
+
+  def clearAllData(): Future[Response] =
+    for { dtResp <- datasetTable.clearAll()
+          ctResp <- columnTable.clearAll() }
+    yield { ctResp }
+
   def newDataset(dataset: Dataset): Future[Response] =
     datasetTable.createNewDataset(dataset)
 

cassandra/src/main/scala/filodb.cassandra/metastore/ColumnTable.scala

@@ -45,6 +45,10 @@ object ColumnTable extends ColumnTable with SimpleCassandraConnector {
   import filodb.cassandra.Util._
   import filodb.core._
 
+  def initialize(): Future[Response] = create.ifNotExists.future().toResponse()
+
+  def clearAll(): Future[Response] = truncate.future().toResponse()
+
   def getSchema(dataset: String, version: Int): Future[Column.Schema] = {
     val enum = select.where(_.dataset eqs dataset).and(_.version lte version)
                      .fetchEnumerator()

cassandra/src/main/scala/filodb.cassandra/metastore/DatasetTable.scala

@@ -42,6 +42,10 @@ object DatasetTable extends DatasetTable with SimpleCassandraConnector {
   import filodb.core._
   import filodb.core.Types._
 
+  def initialize(): Future[Response] = create.ifNotExists.future().toResponse()
+
+  def clearAll(): Future[Response] = truncate.future().toResponse()
+
   def insertProjection(projection: Projection): Future[Response] =
     insert.value(_.name, projection.dataset)
           .value(_.projectionId, projection.id)

cassandra/src/test/scala/filodb.cassandra/AllTablesTest.scala

@@ -37,20 +37,6 @@ trait AllTablesTest extends SimpleCassandraTest {
 
   lazy val metaStore = new CassandraMetaStore(config)
 
-  def createAllTables(): Unit = {
-    val f = for { _ <- DatasetTable.create.ifNotExists.future()
-                  _ <- ColumnTable.create.ifNotExists.future() }
-            yield { 0 }
-    Await.result(f, 10 seconds)
-  }
-
-  def truncateAllTables(): Unit = {
-    val f = for { _ <- DatasetTable.truncate.future()
-                  _ <- ColumnTable.truncate.future() }
-            yield { 0 }
-    Await.result(f, 10 seconds)
-  }
-
   import Column.ColumnType._
 
   val dsName = "gdelt"

cassandra/src/test/scala/filodb.cassandra/metastore/CassandraMetaStoreSpec.scala

@@ -17,10 +17,10 @@ class CassandraMetaStoreSpec extends FunSpec with BeforeAndAfter with AllTablesT
 
   override def beforeAll() {
     super.beforeAll()
-    createAllTables()
+    metastore.initialize().futureValue
   }
 
-  before { truncateAllTables() }
+  before { metastore.clearAllData().futureValue }
 
   describe("column API") {
     it("should return IllegalColumnChange if an invalid column addition submitted") {

core/src/main/scala/filodb.core/metadata/MetaStore.scala

@@ -17,6 +17,16 @@ trait MetaStore {
 
   implicit val ec: ExecutionContext
 
+  /**
+   * Initializes the MetaStore so it is ready for further commands.
+   */
+  def initialize(): Future[Response]
+
+  /**
+   * Clears all dataset and column metadata from the MetaStore.
+   */
+  def clearAllData(): Future[Response]
+
   /**
    * ** Dataset API ***
    */