CLOUDSTACK-8066: There is not way to know the size of the snapshot created.

(cherry picked from commit 9153b8bede)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

api/src/org/apache/cloudstack/api/ApiConstants.java

@@ -613,6 +613,7 @@ public class ApiConstants {
     public static final String REGION_LEVEL_VPC = "regionlevelvpc";
     public static final String STRECHED_L2_SUBNET = "strechedl2subnet";
     public static final String NETWORK_SPANNED_ZONES = "zonesnetworkspans";
+    public static final String PHYSICAL_SIZE = "physicalsize";
 
     public enum HostDetails {
         all, capacity, events, stats, min;

api/src/org/apache/cloudstack/api/response/SnapshotResponse.java

@@ -86,6 +86,10 @@ public class SnapshotResponse extends BaseResponse implements ControlledEntityRe
     @Param(description = "the state of the snapshot. BackedUp means that snapshot is ready to be used; Creating - the snapshot is being allocated on the primary storage; BackingUp - the snapshot is being backed up on secondary storage")
     private Snapshot.State state;
 
+    @SerializedName(ApiConstants.PHYSICAL_SIZE)
+    @Param(description = "physical size of backedup snapshot on image store")
+    private long physicalSize;
+
     @SerializedName(ApiConstants.ZONE_ID)
     @Param(description = "id of the availability zone")
     private String zoneId;
@@ -166,6 +170,10 @@ public class SnapshotResponse extends BaseResponse implements ControlledEntityRe
         this.state = state;
     }
 
+    public void setPhysicaSize(long physicalSize) {
+        this.physicalSize = physicalSize;
+    }
+
     @Override
     public void setProjectId(String projectId) {
         this.projectId = projectId;

engine/api/src/org/apache/cloudstack/engine/subsystem/api/storage/SnapshotInfo.java

@@ -36,4 +36,6 @@ public interface SnapshotInfo extends DataObject, Snapshot {
     ObjectInDataStoreStateMachine.State getStatus();
 
     boolean isRevertable();
+
+    long getPhysicalSize();
 }

engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/SnapshotObject.java

@@ -138,6 +138,16 @@ public class SnapshotObject implements SnapshotInfo {
         return false;
     }
 
+    @Override
+    public long getPhysicalSize() {
+        long physicalSize = 0;
+        SnapshotDataStoreVO snapshotStore = snapshotStoreDao.findBySnapshot(snapshot.getId(), DataStoreRole.Image);
+        if (snapshotStore != null) {
+            physicalSize = snapshotStore.getPhysicalSize();
+        }
+        return physicalSize;
+    }
+
     @Override
     public VolumeInfo getBaseVolume() {
         return volFactory.getVolume(snapshot.getVolumeId());

server/src/com/cloud/api/ApiResponseHelper.java

@@ -470,6 +470,7 @@ public class ApiResponseHelper implements ResponseGenerator {
             snapshotResponse.setRevertable(false);
         } else {
         snapshotResponse.setRevertable(snapshotInfo.isRevertable());
+        snapshotResponse.setPhysicaSize(snapshotInfo.getPhysicalSize());
         }
 
         // set tag information