Fix #223 - Drop vector time when resource is removed

core/src/saros/activities/DeletionAcknowledgmentActivity.java

@@ -0,0 +1,28 @@
+package saros.activities;
+
+import com.thoughtworks.xstream.annotations.XStreamAlias;
+import saros.session.User;
+import saros.session.internal.DeletionAcknowledgmentDispatcher;
+
+/**
+ * Activity for notifying other participants that a file was successfully deleted locally.
+ *
+ * @see DeletionAcknowledgmentDispatcher
+ */
+@XStreamAlias("deletionAcknowledgementActivity")
+public class DeletionAcknowledgmentActivity extends AbstractResourceActivity {
+
+  public DeletionAcknowledgmentActivity(User user, SPath resource) {
+    super(user, resource);
+  }
+
+  @Override
+  public void dispatch(IActivityReceiver receiver) {
+    receiver.receive(this);
+  }
+
+  @Override
+  public String toString() {
+    return this.getClass().getSimpleName() + " : " + getSource() + " - " + getPath();
+  }
+}

core/src/saros/activities/FolderDeletedActivity.java

@@ -1,9 +1,19 @@
 package saros.activities;
 
 import com.thoughtworks.xstream.annotations.XStreamAlias;
+import saros.concurrent.management.ConcurrentDocumentClient;
+import saros.concurrent.management.ConcurrentDocumentServer;
 import saros.session.User;
 
-/** An activity that represents the deletion of a folder made by a user during a session. */
+/**
+ * An activity that represents the deletion of a folder made by a user during a session.
+ *
+ * <p><b>NOTE:</b> Any resource that is contained in the deleted folder should have been processed
+ * separately before dispatching the folder deletion activity. This is important to allow the other
+ * session participants to clean up the state of all deleted child resources. Furthermore, the
+ * explicit handling of deleted child resources is required by the {@link ConcurrentDocumentServer}
+ * and {@link ConcurrentDocumentClient}.
+ */
 @XStreamAlias("folderDeleted")
 public class FolderDeletedActivity extends AbstractResourceActivity
     implements IFileSystemModificationActivity {

core/src/saros/activities/IActivityReceiver.java

@@ -31,6 +31,10 @@ default void receive(ChecksumErrorActivity checksumErrorActivity) {
     /*NOP*/
   }
 
+  default void receive(DeletionAcknowledgmentActivity deletionAcknowledgmentActivity) {
+    /*NOP*/
+  }
+
   default void receive(EditorActivity editorActivity) {
     /*NOP*/
   }

core/src/saros/communication/extensions/ActivitiesExtension.java

@@ -27,6 +27,7 @@
 import saros.activities.ChangeColorActivity;
 import saros.activities.ChecksumActivity;
 import saros.activities.ChecksumErrorActivity;
+import saros.activities.DeletionAcknowledgmentActivity;
 import saros.activities.EditorActivity;
 import saros.activities.FileActivity;
 import saros.activities.FolderCreatedActivity;
@@ -143,6 +144,7 @@ private Provider() {
           ChangeColorActivity.class,
           ChecksumActivity.class,
           ChecksumErrorActivity.class,
+          DeletionAcknowledgmentActivity.class,
           EditorActivity.class,
           FileActivity.class,
           FolderCreatedActivity.class,

core/src/saros/concurrent/jupiter/internal/Jupiter.java

@@ -260,16 +260,20 @@ protected void checkPreconditions(JupiterVectorTime time) throws TransformationE
     if (!this.ackJupiterActivityList.isEmpty()
         && (time.getRemoteOperationCount()
             < this.ackJupiterActivityList.get(0).getLocalOperationCount())) {
+      // TODO improve exception message; what is precondition 1?
       throw new TransformationException("Precondition #1 violated.");
     } else if (time.getRemoteOperationCount() > this.vectorTime.getLocalOperationCount()) {
       throw new TransformationException(
-          "precondition #2 violated (Remote vector time is greater than local vector time).");
+          "precondition #2 violated (Remote vector time is greater than local vector time) - remote time: "
+              + time
+              + " ,local time: "
+              + vectorTime);
     } else if (time.getLocalOperationCount() != this.vectorTime.getRemoteOperationCount()) {
       throw new TransformationException(
-          "Precondition #3 violated (Vector time does not match): "
+          "Precondition #3 violated (Vector time does not match) - remote time :"
               + time
-              + " , "
-              + this.vectorTime);
+              + " ,local time: "
+              + vectorTime);
     }
   }
 

core/src/saros/concurrent/management/ConcurrentDocumentClient.java

@@ -4,14 +4,13 @@
 import java.util.List;
 import org.apache.log4j.Logger;
 import saros.activities.ChecksumActivity;
-import saros.activities.FileActivity;
 import saros.activities.IActivity;
-import saros.activities.IActivityReceiver;
 import saros.activities.JupiterActivity;
 import saros.activities.SPath;
 import saros.activities.TextEditActivity;
 import saros.concurrent.jupiter.Operation;
 import saros.concurrent.jupiter.TransformationException;
+import saros.repackaged.picocontainer.Startable;
 import saros.session.ISarosSession;
 
 /**
@@ -24,18 +23,31 @@
  * <p>When JupiterActivities are received from the server they are transformed by the
  * ConcurrentDocumentClient to TextEditActivities which can then be executed locally.
  */
-public class ConcurrentDocumentClient {
+public class ConcurrentDocumentClient implements Startable {
 
   private static Logger log = Logger.getLogger(ConcurrentDocumentClient.class);
 
   private final ISarosSession sarosSession;
 
   private final JupiterClient jupiterClient;
 
-  public ConcurrentDocumentClient(ISarosSession sarosSession) {
+  private final ResourceActivityFilter resourceActivityFilter;
 
+  public ConcurrentDocumentClient(ISarosSession sarosSession) {
     this.sarosSession = sarosSession;
     this.jupiterClient = new JupiterClient(sarosSession);
+
+    this.resourceActivityFilter = new ResourceActivityFilter(sarosSession, this::reset);
+  }
+
+  @Override
+  public void start() {
+    resourceActivityFilter.initialize();
+  }
+
+  @Override
+  public void stop() {
+    resourceActivityFilter.dispose();
   }
 
   /**
@@ -68,6 +80,9 @@ public IActivity transformToJupiter(IActivity activity) {
       return jupiterClient.withTimestamp(checksumActivity);
 
     } else {
+      resourceActivityFilter.handleFileDeletion(activity);
+      resourceActivityFilter.handleFileCreation(activity);
+
       return activity;
     }
   }
@@ -78,6 +93,9 @@ public IActivity transformToJupiter(IActivity activity) {
    * <p>This method will transform them back from Jupiter-specific activities to locally executable
    * activities. @GUI Must be called on the GUI Thread to ensure proper synchronization
    *
+   * <p>Drops activities that are reported as filtered out by {@link
+   * ResourceActivityFilter#isFiltered(IActivity)}.
+   *
    * @host and @client This is called whenever activities are received from REMOTELY both on the
    *     client and on the host
    * @param activity The activity to be transformed
@@ -91,7 +109,13 @@ public List<IActivity> transformFromJupiter(IActivity activity) {
     List<IActivity> activities = new ArrayList<IActivity>();
 
     try {
-      activity.dispatch(clientReceiver);
+      resourceActivityFilter.handleFileCreation(activity);
+
+      if (resourceActivityFilter.isFiltered(activity)) {
+        log.debug("Ignored activity for already deleted resource: " + activity);
+
+        return activities;
+      }
 
       if (activity instanceof JupiterActivity) {
         activities.addAll(receiveActivity((JupiterActivity) activity));
@@ -102,6 +126,8 @@ public List<IActivity> transformFromJupiter(IActivity activity) {
         activities.add(activity);
       }
 
+      resourceActivityFilter.handleFileDeletion(activity);
+
     } catch (Exception e) {
       log.error("Error while transforming activity: " + activity, e);
     }
@@ -123,17 +149,6 @@ private IActivity receiveChecksum(ChecksumActivity activity) {
     return activity;
   }
 
-  /** Used to remove JupiterClientDocuments for deleted files */
-  private final IActivityReceiver clientReceiver =
-      new IActivityReceiver() {
-        @Override
-        public void receive(FileActivity fileActivity) {
-          if (fileActivity.getType() == FileActivity.Type.REMOVED) {
-            jupiterClient.reset(fileActivity.getPath());
-          }
-        }
-      };
-
   /**
    * Transforms the JupiterActivity back into textEditActivities.
    *
@@ -174,7 +189,7 @@ private List<IActivity> receiveActivity(JupiterActivity jupiterActivity) {
    *     authoritative one and thus does not need to be reset).
    */
   public synchronized void reset(SPath path) {
-    log.debug("Resetting jupiter client: " + path.toString());
+    log.debug("Resetting jupiter client for " + path);
     jupiterClient.reset(path);
   }
 

core/src/saros/concurrent/management/ConcurrentDocumentServer.java

@@ -4,11 +4,10 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.function.Consumer;
 import org.apache.log4j.Logger;
 import saros.activities.ChecksumActivity;
-import saros.activities.FileActivity;
 import saros.activities.IActivity;
-import saros.activities.IActivityReceiver;
 import saros.activities.JupiterActivity;
 import saros.activities.QueueItem;
 import saros.activities.SPath;
@@ -35,6 +34,8 @@ public class ConcurrentDocumentServer implements Startable {
 
   private final JupiterServer server;
 
+  private final ResourceActivityFilter resourceActivityFilter;
+
   /** {@link ISessionListener} for updating Jupiter documents on the host. */
   private final ISessionListener sessionListener =
       new ISessionListener() {
@@ -53,42 +54,46 @@ public void userLeft(final User user) {
   public ConcurrentDocumentServer(final ISarosSession sarosSession) {
     this.sarosSession = sarosSession;
     this.server = new JupiterServer(sarosSession);
+
+    Consumer<SPath> deletedFileHandler =
+        resource -> {
+          LOG.debug("Resetting jupiter server for " + resource);
+          server.removePath(resource);
+        };
+
+    this.resourceActivityFilter = new ResourceActivityFilter(sarosSession, deletedFileHandler);
   }
 
   @Override
   public void start() {
     sarosSession.addListener(sessionListener);
+    resourceActivityFilter.initialize();
   }
 
   @Override
   public void stop() {
     sarosSession.removeListener(sessionListener);
+    resourceActivityFilter.dispose();
   }
 
   /**
-   * Dispatched the activity to the internal ActivityReceiver. The ActivityReceiver will remove
-   * FileDocuments when the file has been deleted.
+   * Calls {@link ResourceActivityFilter#handleFileDeletion(IActivity)} and {@link
+   * ResourceActivityFilter#handleFileCreation(IActivity)} with the given activity.
    *
-   * @param activity Activity to be dispatched
+   * @param activity the activity to handle
    */
-  public void checkFileDeleted(final IActivity activity) {
-    activity.dispatch(hostReceiver);
+  public void handleResourceChange(IActivity activity) {
+    resourceActivityFilter.handleFileDeletion(activity);
+    resourceActivityFilter.handleFileCreation(activity);
   }
 
-  private final IActivityReceiver hostReceiver =
-      new IActivityReceiver() {
-        @Override
-        public void receive(final FileActivity activity) {
-          if (activity.getType() == FileActivity.Type.REMOVED) {
-            server.removePath(activity.getPath());
-          }
-        }
-      };
-
   /**
    * Transforms the given activities on the server side and returns a list of QueueItems containing
    * the transformed activities and there receivers.
    *
+   * <p>Drops activities that are reported as filtered out by {@link
+   * ResourceActivityFilter#isFiltered(IActivity)}.
+   *
    * @host
    * @sarosThread Must be executed in the Saros dispatch thread.
    * @notGUI This method may not be called from SWT, otherwise a deadlock might occur!!
@@ -104,9 +109,13 @@ public List<QueueItem> transformIncoming(final IActivity activity) {
 
     final List<QueueItem> result = new ArrayList<QueueItem>();
 
-    try {
-      activity.dispatch(hostReceiver);
+    if (resourceActivityFilter.isFiltered(activity)) {
+      LOG.debug("Ignored activity for already deleted resource: " + activity);
+
+      return result;
+    }
 
+    try {
       if (activity instanceof JupiterActivity) {
         result.addAll(receive((JupiterActivity) activity));