Implemented instance DAO and first tests

Test cases need to be extended

Author: Johannes Duesing

src/main/scala/de/upb/cs/swt/delphi/instanceregistry/daos/DynamicInstanceDAO.scala

@@ -0,0 +1,79 @@
+package de.upb.cs.swt.delphi.instanceregistry.daos
+
+import akka.actor.ActorSystem
+import de.upb.cs.swt.delphi.instanceregistry.{AppLogging, Server}
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.Instance
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.InstanceEnums.ComponentType
+
+import scala.collection.mutable
+import scala.util.{Failure, Success, Try}
+
+/**
+  * Implementation of the instance data access object that keeps its data in memory
+  * instead of using a persistent storage.
+  */
+class DynamicInstanceDAO extends InstanceDAO with AppLogging {
+
+  private val instances : mutable.Set[Instance] = new mutable.HashSet[Instance]()
+  implicit val system : ActorSystem = Server.system
+
+  override def addInstance(instance: Instance): Try[Unit] = {
+    //Verify ID is present in instance
+    if(instance.id.isEmpty){
+      val msg = s"Cannot add instance ${instance.name}, id is empty!"
+      log.warning(msg)
+      Failure(new RuntimeException(msg))
+    } else {
+      //Verify id is not already present in instances!
+      if(!hasInstance(instance.id.get)){
+        instances.add(instance)
+        Success(log.info(s"Added instance ${instance.name} with id ${instance.id} to database."))
+      } else {
+        val msg = s"Cannot add instance ${instance.name}, id ${instance.id} already present."
+        log.warning(msg)
+        Failure(new RuntimeException(msg))
+      }
+    }
+  }
+
+  override def hasInstance(id: Long): Boolean = {
+    //addInstance verifies that id : Option[Long] is not empty, so can apply .get here!
+    val query = instances filter {i => i.id.get == id}
+    query.nonEmpty
+  }
+
+  override def removeInstance(id: Long): Try[Unit] = {
+    if(hasInstance(id)){
+      //AddInstance verifies that id is always present, hasInstance verifies that find will return an instance
+      instances.remove(instances.find(i => i.id.get == id).get)
+      Success(log.info(s"Successfully removed instance with id $id."))
+    } else {
+      val msg = s"Cannot remove instance with id $id, that id is not present."
+      log.warning(msg)
+      Failure(new RuntimeException(msg))
+    }
+  }
+
+  override def getInstance(id: Long): Option[Instance] = {
+    if(hasInstance(id)) {
+      val query = instances filter {i => i.id.get == id}
+      val instance  = query.iterator.next()
+      Some(instance)
+    } else {
+      None
+    }
+  }
+
+  override def getInstancesOfType(componentType: ComponentType): List[Instance] = {
+    List() ++ instances filter {i => i.componentType == componentType}
+  }
+
+  override def getAllInstances(): List[Instance] = {
+    List() ++ instances
+  }
+
+  override def clearAll() : Unit = {
+    instances.clear()
+  }
+
+}

src/main/scala/de/upb/cs/swt/delphi/instanceregistry/daos/InstanceDAO.scala

@@ -0,0 +1,59 @@
+package de.upb.cs.swt.delphi.instanceregistry.daos
+
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.Instance
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.InstanceEnums.ComponentType
+
+import scala.util.Try
+
+/**
+  * An Data Access Object to access the set of registered instances
+  */
+trait InstanceDAO {
+
+  /***
+    * Add a new instance to the DAO.
+    * @param instance Instance to add (attribute 'id' must not be empty!)
+    * @return Success if id was not already present, Failure otherwise
+    */
+  def addInstance(instance : Instance) : Try[Unit]
+
+  /**
+    * Checks whether the DAO holds an instance with the specified id.
+    * @param id Id to look for
+    * @return True if id is present, false otherwise
+    */
+  def hasInstance(id: Long) : Boolean
+
+  /**
+    * Removes the instance with the given id from the DAO.
+    * @param id Id of the instance that will be removed
+    * @return Success if id was present, Failure otherwise
+    */
+  def removeInstance(id: Long) : Try[Unit]
+
+  /**
+    * Gets the instance with the specified id from the DAO
+    * @param id Id of the instance to retrieve
+    * @return Some(instance) if present, else None
+    */
+  def getInstance(id: Long) : Option[Instance]
+
+  /**
+    * Retrieves all instances of the specified ComponentType from the DAO
+    * @param componentType ComponentType to look for
+    * @return A list of instances with the specified type
+    */
+  def getInstancesOfType(componentType : ComponentType) : List[Instance]
+
+  /**
+    * Retrieves all instances from the DAO
+    * @return A list of all instances in the DAO
+    */
+  def getAllInstances() : List[Instance]
+
+  /**
+    * Removes all instances from the DAO
+    */
+  def clearAll() : Unit
+
+}

src/test/scala/de/upb/cs/swt/delphi/instanceregistry/daos/DynamicInstanceDAOTest.scala

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+package de.upb.cs.swt.delphi.instanceregistry.daos
+
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.Instance
+import de.upb.cs.swt.delphi.instanceregistry.io.swagger.client.model.InstanceEnums.ComponentType
+import org.scalatest.{BeforeAndAfterAll, FlatSpec, Matchers}
+
+class DynamicInstanceDAOTest extends FlatSpec with Matchers with BeforeAndAfterAll{
+
+  val dao : InstanceDAO = new DynamicInstanceDAO()
+
+  private def buildInstance(id : Int) : Instance = {
+    Instance(Some(id), "https://localhost", 12345, "TestInstance", ComponentType.Crawler)
+  }
+
+  override protected def beforeAll() : Unit = {
+    dao.clearAll()
+    for(i <- 1 to 3){
+      dao.addInstance(buildInstance(i))
+    }
+  }
+
+  "The instance DAO" must "be able to add an get an instance with a new id" in {
+    assert(dao.addInstance(buildInstance(4)).isSuccess)
+    assert(dao.getAllInstances().size == 4)
+    assert(dao.hasInstance(4))
+    assert(dao.removeInstance(4).isSuccess)
+  }
+
+}