Closes #10

- Several classes were refactored to stop working with IDs and starting providing a true object oriented framework.
  Lots of attributes that were defined as a List of Integer or as a Map where the key was Integer, to store
  the ID of entities, were changed to store the object itself not its ID.
  It makes the framework far less error prone, since the Lists and Maps will just accept
  the defined object.
- It makes even clear to understand the framework code and to use it, since
  that when a developer look at some of such Lists or Maps, he/she will immediately know
  what such Lists/Maps are storing.
- Storing actual objects instead of their IDs also improves the framework performance
  since it doesn't have to get the object ID and look for the actual object inside
  another List that in fact stored the objects (as it was common to be done).
- Message passing mechanisms was also improved, storing actual objects into the SimEvent.data attribute
  instead of the object ID. The source and destionation of a message sent is also performed internally
  using just the ID, because changing these behaviour would require far more work.
- The documentation of such Lists/Maps was reviewed and updated.
- Network related classes were those ones that received lots of changes, mainly NetworkPacket implementing classes.

cloudsim-plus-examples/src/main/java/org/cloudbus/cloudsim/examples/network/datacenter/NetworkVmExampleAbstract.java

@@ -217,7 +217,7 @@ protected void createNetwork(NetworkDatacenter datacenter) {
 
         for (NetworkHost host : datacenter.<NetworkHost>getHostList()) {
             int switchNum = host.getId() / edgeSwitches[0].getPorts();
-            edgeSwitches[switchNum].getHostList().put(host.getId(), host);
+            edgeSwitches[switchNum].connectHost(host);
             datacenter.addHostToSwitch(host, edgeSwitches[switchNum]);
             host.setEdgeSwitch(edgeSwitches[switchNum]);
         }

cloudsim-plus-examples/src/main/java/org/cloudbus/cloudsim/examples/network/datacenter/NetworkVmsExample1.java

@@ -165,7 +165,7 @@ private void createNetwork(NetworkDatacenter datacenter) {
 
         for (NetworkHost host : datacenter.<NetworkHost>getHostList()) {
             int switchNum = host.getId() / edgeSwitches[0].getPorts();
-            edgeSwitches[switchNum].getHostList().put(host.getId(), host);
+            edgeSwitches[switchNum].connectHost(host);
             datacenter.addHostToSwitch(host, edgeSwitches[switchNum]);
             host.setEdgeSwitch(edgeSwitches[switchNum]);
         }
@@ -267,7 +267,7 @@ private void addSendTask(
      */
     private void addReceiveTask(NetworkCloudlet cloudlet, NetworkCloudlet sourceCloudlet) {
         CloudletReceiveTask task = new CloudletReceiveTask(
-                cloudlet.getTasks().size(), sourceCloudlet.getVm().getId());
+                cloudlet.getTasks().size(), sourceCloudlet.getVm());
         task.setMemory(TASK_RAM);
         task.setNumberOfExpectedPacketsToReceive(NUMBER_OF_PACKETS_TO_SEND);
         cloudlet.addTask(task);

cloudsim-plus-examples/src/main/java/org/cloudbus/cloudsim/examples/network/datacenter/NetworkVmsExampleBagOfTasksApp.java

@@ -79,7 +79,7 @@ public List<NetworkCloudlet> createNetworkCloudlets(DatacenterBroker broker){
             //NetworkCloudlet 0 wait data from other cloudlets, while the other cloudlets send data
             if (i==0){
                 for(int j=1; j < NETCLOUDLETS_FOR_EACH_APP; j++) {
-                    task = new CloudletReceiveTask(taskStageId++, selectedVms.get(j+1).getId());
+                    task = new CloudletReceiveTask(taskStageId++, selectedVms.get(j+1));
                     task.setMemory(memory);
                     cloudlet.addTask(task);
                 }

cloudsim-plus-examples/src/main/java/org/cloudbus/cloudsim/examples/network/datacenter/NetworkVmsExampleWorkflowApp.java

@@ -102,7 +102,7 @@ private void addSendTask(
      */
     private void addReceiveTask(NetworkCloudlet cloudlet, NetworkCloudlet sourceCloudlet) {
         CloudletReceiveTask task = new CloudletReceiveTask(
-                cloudlet.getTasks().size(), sourceCloudlet.getVm().getId());
+                cloudlet.getTasks().size(), sourceCloudlet.getVm());
         task.setMemory(NETCLOUDLET_RAM);
         task.setNumberOfExpectedPacketsToReceive(NUMBER_OF_PACKETS_TO_SEND);
         cloudlet.addTask(task);

cloudsim-plus-testbeds/src/main/java/org/cloudsimplus/sla/NetworkVmsExampleWithMetrics.java

@@ -254,7 +254,7 @@ protected void createNetwork(NetworkDatacenter datacenter) {
 
         for (NetworkHost host : datacenter.<NetworkHost>getHostList()) {
             int switchNum = host.getId() / edgeSwitches[0].getPorts();
-            edgeSwitches[switchNum].getHostList().put(host.getId(), host);
+            edgeSwitches[switchNum].connectHost(host);
             datacenter.addHostToSwitch(host, edgeSwitches[switchNum]);
             host.setEdgeSwitch(edgeSwitches[switchNum]);
         }

cloudsim-plus/pom.xml

@@ -84,7 +84,7 @@
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-javadoc-plugin</artifactId>
                         <configuration>
-                            <!-- Switch OFF the doclint in Java 8 -->
+                            <!-- AbstractSwitch OFF the doclint in Java 8 -->
                             <additionalparam>-Xdoclint:none</additionalparam>
                         </configuration>
                     </plugin>
@@ -133,7 +133,7 @@
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-javadoc-plugin</artifactId>
                         <configuration>
-                            <!-- Switch OFF the doclint in Java 8 -->
+                            <!-- AbstractSwitch OFF the doclint in Java 8 -->
                             <additionalparam>-Xdoclint:none</additionalparam>
                         </configuration>
                     </plugin>

cloudsim-plus/src/main/java/org/cloudbus/cloudsim/allocationpolicies/VmAllocationPolicyAbstract.java

@@ -14,7 +14,6 @@
 
 import org.cloudbus.cloudsim.datacenters.Datacenter;
 import org.cloudbus.cloudsim.hosts.Host;
-import org.cloudbus.cloudsim.hosts.power.PowerHost;
 import org.cloudbus.cloudsim.vms.Vm;
 import org.cloudsimplus.listeners.HostToVmEventInfo;
 
@@ -37,7 +36,7 @@ public abstract class VmAllocationPolicyAbstract implements VmAllocationPolicy {
     /**
      * @see #getVmHostMap()
      */
-    private Map<String, Host> vmTable;
+    private Map<Vm, Host> vmTable;
 
     /**
      * @see #getDatacenter()
@@ -50,7 +49,7 @@ public abstract class VmAllocationPolicyAbstract implements VmAllocationPolicy {
     /**
      * @see #getUsedPes()
      */
-    private Map<String, Integer> usedPes;
+    private Map<Vm, Integer> usedPes;
 
     /**
      * Creates a new VmAllocationPolicy object.
@@ -73,7 +72,7 @@ public <T extends Host> List<T> getHostList() {
      *
      * @return the VM map
      */
-    protected Map<String, Host> getVmHostMap() {
+    protected Map<Vm, Host> getVmHostMap() {
         return vmTable;
     }
 
@@ -82,7 +81,7 @@ protected Map<String, Host> getVmHostMap() {
      *
      * @param vmTable the vm table
      */
-    protected final void setVmTable(Map<String, Host> vmTable) {
+    protected final void setVmTable(Map<Vm, Host> vmTable) {
         this.vmTable = vmTable;
     }
 
@@ -98,7 +97,7 @@ protected void mapVmToPm(Vm vm, Host host) {
             return;
         }
 
-        getVmHostMap().put(vm.getUid(), host);
+        getVmHostMap().put(vm, host);
         HostToVmEventInfo info =
             new HostToVmEventInfo(host.getSimulation().clock(), host, vm);
         vm.getOnHostAllocationListener().update(info);
@@ -118,7 +117,7 @@ protected Host unmapVmFromPm(Vm vm) {
             return Host.NULL;
         }
 
-        Host host = getVmHostMap().remove(vm.getUid());
+        Host host = getVmHostMap().remove(vm);
         if(Objects.isNull(host)) {
             return Host.NULL;
         }
@@ -186,11 +185,11 @@ protected final VmAllocationPolicy setHostFreePesMap(Map<Host, Integer> hostFree
 
     /**
      * Gets the map between each VM and the number of PEs used. The map key is a
-     * VM UID and the value is the number of used Pes for that VM.
+     * VM and the value is the number of used Pes for that VM.
      *
      * @return the used PEs map
      */
-    protected Map<String, Integer> getUsedPes() {
+    protected Map<Vm, Integer> getUsedPes() {
         return usedPes;
     }
 
@@ -199,7 +198,7 @@ protected Map<String, Integer> getUsedPes() {
      *
      * @param usedPes the used pes
      */
-    protected final void setUsedPes(Map<String, Integer> usedPes) {
+    protected final void setUsedPes(Map<Vm, Integer> usedPes) {
         this.usedPes = usedPes;
     }
 }

cloudsim-plus/src/main/java/org/cloudbus/cloudsim/allocationpolicies/VmAllocationPolicySimple.java

@@ -9,11 +9,10 @@
 
 import java.util.*;
 
+import org.cloudbus.cloudsim.core.UniquelyIdentificable;
 import org.cloudbus.cloudsim.hosts.Host;
-import org.cloudbus.cloudsim.hosts.power.PowerHost;
 import org.cloudbus.cloudsim.util.Log;
 import org.cloudbus.cloudsim.vms.Vm;
-import org.cloudbus.cloudsim.vms.VmSimple;
 
 /**
  * A VmAllocationPolicy implementation that chooses, as
@@ -57,7 +56,7 @@ public boolean allocateHostForVm(Vm vm) {
         }
 
         // if this vm was already created
-        if (getVmHostMap().containsKey(vm.getUid())) {
+        if (getVmHostMap().containsKey(vm)) {
             return false;
         }
 
@@ -69,7 +68,7 @@ public boolean allocateHostForVm(Vm vm) {
             final int hostFreePes = entry.getValue();
             if (host.vmCreate(vm)) {
                 mapVmToPm(vm, host);
-                getUsedPes().put(vm.getUid(), vm.getNumberOfPes());
+                getUsedPes().put(vm, vm.getNumberOfPes());
                 getHostFreePesMap().put(host, hostFreePes - vm.getNumberOfPes());
                 if(!hostsWhereVmCreationFailed.isEmpty()){
                     Log.printFormattedLine("[VmAllocationPolicy] VM #%d was successfully allocated to Host #%d", vm.getId(), host.getId());
@@ -104,7 +103,7 @@ private Map.Entry<Host, Integer> getHostWithLessUsedPes(List<Host> ignoredHosts)
     @Override
     public void deallocateHostForVm(Vm vm) {
         Host host = unmapVmFromPm(vm);
-        int pes = getUsedPes().remove(vm.getUid());
+        int pes = getUsedPes().remove(vm);
         if (host != Host.NULL) {
             host.destroyVm(vm);
             getHostFreePesMap().put(host, getHostFreePesMap().get(host) + pes);
@@ -113,12 +112,12 @@ public void deallocateHostForVm(Vm vm) {
 
     @Override
     public Host getHost(Vm vm) {
-        return getVmHostMap().get(vm.getUid());
+        return getVmHostMap().get(vm);
     }
 
     @Override
     public Host getHost(int vmId, int userId) {
-        return getVmHostMap().get(VmSimple.getUid(userId, vmId));
+        return getVmHostMap().get(UniquelyIdentificable.getUid(userId, vmId));
     }
 
     /**
@@ -141,7 +140,7 @@ public boolean allocateHostForVm(Vm vm, Host host) {
 
         mapVmToPm(vm, host);
         final int requiredPes = vm.getNumberOfPes();
-        getUsedPes().put(vm.getUid(), requiredPes);
+        getUsedPes().put(vm, requiredPes);
         getHostFreePesMap().put(host, getHostFreePesMap().get(host) - requiredPes);
 
         Log.printFormattedLine(

cloudsim-plus/src/main/java/org/cloudbus/cloudsim/allocationpolicies/power/PowerVmAllocationPolicyAbstract.java

@@ -12,13 +12,12 @@
 import java.util.Map;
 import java.util.Objects;
 
+import org.cloudbus.cloudsim.core.UniquelyIdentificable;
 import org.cloudbus.cloudsim.hosts.Host;
 import org.cloudbus.cloudsim.hosts.power.PowerHost;
 import org.cloudbus.cloudsim.util.Log;
-import org.cloudbus.cloudsim.hosts.power.PowerHostSimple;
 import org.cloudbus.cloudsim.vms.Vm;
 import org.cloudbus.cloudsim.allocationpolicies.VmAllocationPolicyAbstract;
-import org.cloudbus.cloudsim.vms.VmSimple;
 import org.cloudbus.cloudsim.core.Simulation;
 
 /**
@@ -42,7 +41,7 @@ public abstract class PowerVmAllocationPolicyAbstract extends VmAllocationPolicy
     /**
      * @see #getVmHostMap()
      */
-    private final Map<String, Host> vmHostMap = new HashMap<>();
+    private final Map<Vm, Host> vmHostMap = new HashMap<>();
 
     /**
      * Creates a PowerVmAllocationPolicy.
@@ -65,7 +64,7 @@ public boolean allocateHostForVm(Vm vm, Host host) {
         }
 
         if (host.vmCreate(vm)) { // if vm has been successfully created in the host
-            getVmHostMap().put(vm.getUid(), host);
+            getVmHostMap().put(vm, host);
             Log.printFormattedLine(
                 "%.2f: VM #" + vm.getId() + " has been allocated to the host #" + host.getId(),
                 simulation.clock());
@@ -86,20 +85,20 @@ public PowerHost findHostForVm(Vm vm) {
 
     @Override
     public void deallocateHostForVm(Vm vm) {
-        Host host = getVmHostMap().remove(vm.getUid());
+        Host host = getVmHostMap().remove(vm);
         if (!Objects.isNull(host)) {
             host.destroyVm(vm);
         }
     }
 
     @Override
     public Host getHost(Vm vm) {
-        return getVmHostMap().get(vm.getUid());
+        return getVmHostMap().get(vm);
     }
 
     @Override
     public Host getHost(int vmId, int userId) {
-        return getVmHostMap().get(VmSimple.getUid(userId, vmId));
+        return getVmHostMap().get(UniquelyIdentificable.getUid(userId, vmId));
     }
 
     /**
@@ -108,7 +107,7 @@ public Host getHost(int vmId, int userId) {
      *
      * @return
      */
-    public Map<String, Host> getVmHostMap() {
+    public Map<Vm, Host> getVmHostMap() {
         return vmHostMap;
     }
 

cloudsim-plus/src/main/java/org/cloudbus/cloudsim/allocationpolicies/power/PowerVmAllocationPolicyMigrationAbstract.java

@@ -60,9 +60,9 @@ public abstract class PowerVmAllocationPolicyMigrationAbstract extends PowerVmAl
 
     /**
      * A map of CPU utilization history (in percentage) for each host, where
-     * each key is a host id and each value is the CPU utilization percentage history.
+     * each key is a hos and each value is the CPU utilization percentage history.
      */
-    private final Map<Integer, List<Double>> utilizationHistory = new HashMap<>();
+    private final Map<Host, List<Double>> utilizationHistory = new HashMap<>();
 
     /**
      * The metric history.
@@ -71,13 +71,13 @@ public abstract class PowerVmAllocationPolicyMigrationAbstract extends PowerVmAl
      * threshold, other it stores utilization threshold or predicted
      * utilization, that is very confusing.
      */
-    private final Map<Integer, List<Double>> metricHistory = new HashMap<>();
+    private final Map<Host, List<Double>> metricHistory = new HashMap<>();
 
     /**
      * The time when entries in each history list was added. All history lists
      * are updated at the same time.
      */
-    private final Map<Integer, List<Double>> timeHistory = new HashMap<>();
+    private final Map<Host, List<Double>> timeHistory = new HashMap<>();
 
     /**
      * The history of time spent in VM selection every time the optimization of
@@ -505,7 +505,7 @@ protected void restoreAllocation() {
                         "Couldn't restore VM #%d on host #%d",
                         vm.getId(), host.getId()));
             }
-            getVmHostMap().put(vm.getUid(), host);
+            getVmHostMap().put(vm, host);
         }
     }
 
@@ -576,15 +576,14 @@ protected double getUtilizationOfCpuMips(PowerHost host) {
      */
     protected void addHistoryEntryIfAbsent(PowerHost host, double metric) {
         Simulation simulation = host.getSimulation();
-        final int hostId = host.getId();
-        getTimeHistory().putIfAbsent(hostId, new LinkedList<>());
-        getUtilizationHistory().putIfAbsent(hostId, new LinkedList<>());
-        getMetricHistory().putIfAbsent(hostId, new LinkedList<>());
-
-        if (!getTimeHistory().get(hostId).contains(simulation.clock())) {
-            getTimeHistory().get(hostId).add(simulation.clock());
-            getUtilizationHistory().get(hostId).add(host.getUtilizationOfCpu());
-            getMetricHistory().get(hostId).add(metric);
+        getTimeHistory().putIfAbsent(host, new LinkedList<>());
+        getUtilizationHistory().putIfAbsent(host, new LinkedList<>());
+        getMetricHistory().putIfAbsent(host, new LinkedList<>());
+
+        if (!getTimeHistory().get(host).contains(simulation.clock())) {
+            getTimeHistory().get(host).add(simulation.clock());
+            getUtilizationHistory().get(host).add(host.getUtilizationOfCpu());
+            getMetricHistory().get(host).add(metric);
         }
     }
 
@@ -620,7 +619,7 @@ protected PowerVmSelectionPolicy getVmSelectionPolicy() {
      *
      * @return the utilization history
      */
-    public Map<Integer, List<Double>> getUtilizationHistory() {
+    public Map<Host, List<Double>> getUtilizationHistory() {
         return utilizationHistory;
     }
 
@@ -629,7 +628,7 @@ public Map<Integer, List<Double>> getUtilizationHistory() {
      *
      * @return the metric history
      */
-    public Map<Integer, List<Double>> getMetricHistory() {
+    public Map<Host, List<Double>> getMetricHistory() {
         return metricHistory;
     }
 
@@ -638,7 +637,7 @@ public Map<Integer, List<Double>> getMetricHistory() {
      *
      * @return the time history
      */
-    public Map<Integer, List<Double>> getTimeHistory() {
+    public Map<Host, List<Double>> getTimeHistory() {
         return timeHistory;
     }