add comment and clean up a bit

functional-test/src/main/java/org/zanata/page/webtrans/EditorPage.java

@@ -2,13 +2,7 @@
 
 import java.util.Collections;
 import java.util.List;
-import java.util.concurrent.Callable;
 
-import javax.activation.CommandObject;
-import javax.annotation.Nullable;
-
-import org.hamcrest.Description;
-import org.hamcrest.Matcher;
 import org.openqa.selenium.By;
 import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebElement;
@@ -18,7 +12,6 @@
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;
 import com.google.common.base.Predicate;
-import com.google.common.base.Throwables;
 import lombok.extern.slf4j.Slf4j;
 
 /**

functional-test/src/test/java/org/zanata/feature/concurrentedit/ConcurrentEditTest.java

@@ -59,7 +59,6 @@ public void editorReceivesRestServiceResults() {
         restCaller.postSourceDocResource(projectSlug, iterationSlug,
                 sourceResource, false);
 
-        // open editor
         // open editor
         new LoginWorkFlow().signIn("admin", "admin");
         // webTrans

zanata-war/src/main/java/org/zanata/events/TextFlowTargetUpdateContextEvent.java

@@ -9,13 +9,20 @@
 import lombok.RequiredArgsConstructor;
 
 /**
- * @author Patrick Huang
- *         <a href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
+ * This event is raised by text flow target update initiator before making a
+ * change. Hibernate entity listener will be triggered after the change is made
+ * and at that point this context information is retrieved from cache.
+ *
+ * @see org.zanata.webtrans.server.TranslationUpdateListener
+ *
+ * @author Patrick Huang <a
+ *         href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
  */
 @RequiredArgsConstructor
 @Getter
 public class TextFlowTargetUpdateContextEvent {
-    public static final String EVENT_NAME = "org.zanata.event.TextFlowTargetUpdateContextEvent";
+    public static final String EVENT_NAME =
+            "org.zanata.event.TextFlowTargetUpdateContextEvent";
 
     private final TransUnitId transUnitId;
     private final LocaleId localeId;

zanata-war/src/main/java/org/zanata/events/TextFlowTargetUpdatedEvent.java

@@ -6,13 +6,22 @@
 import lombok.RequiredArgsConstructor;
 
 /**
- * @author Patrick Huang
- *         <a href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
+ * This event is raised in Hibernate entity listener after change has been made.
+ *
+ * We then gather all relevant information required for TransUnitUpdated object
+ * creation.
+ *
+ * @see org.zanata.webtrans.server.HibernateIntegrator
+ * @see org.zanata.webtrans.shared.rpc.TransUnitUpdated
+ * @see org.zanata.webtrans.server.rpc.TransUnitUpdateHelper
+ * @author Patrick Huang <a
+ *         href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
  */
 @RequiredArgsConstructor
 @Getter
 public class TextFlowTargetUpdatedEvent {
-    public static final String EVENT_NAME = "org.zanata.events.TextFlowTargetUpdatedEvent";
+    public static final String EVENT_NAME =
+            "org.zanata.events.TextFlowTargetUpdatedEvent";
 
     private final TranslationWorkspace workspace;
     private final Long textFlowTargetId;

zanata-war/src/main/java/org/zanata/webtrans/server/HibernateIntegrator.java

@@ -13,6 +13,8 @@
 import lombok.extern.slf4j.Slf4j;
 
 /**
+ * Hibernate SPI. Register event listener for entity lifecycle events.
+ *
  * @author Patrick Huang <a
  *         href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
  */
@@ -29,6 +31,9 @@ public void integrate(Configuration configuration,
                     (TranslationUpdateListener) Component
                             .getInstance(TranslationUpdateListener.class);
             log.info("register event listener: {}", updateListener);
+            // We have to use POST_UPDATE not POST_UPDATE_COMMIT. Because we
+            // still need to access some other entities to make transunit. After
+            // commit the transaction is closed.
             eventListenerRegistry.appendListeners(EventType.POST_UPDATE,
                     updateListener);
             eventListenerRegistry.appendListeners(EventType.POST_INSERT,

zanata-war/src/main/java/org/zanata/webtrans/server/TranslationUpdateListener.java

@@ -2,25 +2,19 @@
 
 import java.util.concurrent.TimeUnit;
 
-import javax.servlet.http.HttpSession;
-
 import org.hibernate.event.spi.PostInsertEvent;
 import org.hibernate.event.spi.PostInsertEventListener;
 import org.hibernate.event.spi.PostUpdateEvent;
 import org.hibernate.event.spi.PostUpdateEventListener;
-import org.jboss.seam.Component;
 import org.jboss.seam.ScopeType;
 import org.jboss.seam.annotations.AutoCreate;
 import org.jboss.seam.annotations.In;
 import org.jboss.seam.annotations.Name;
 import org.jboss.seam.annotations.Observer;
 import org.jboss.seam.annotations.Scope;
-import org.jboss.seam.contexts.Contexts;
-import org.jboss.seam.contexts.SessionContext;
 import org.jboss.seam.core.Events;
 import org.jboss.seam.util.Work;
 import org.jboss.seam.web.ServletContexts;
-import org.jboss.seam.web.Session;
 import org.zanata.common.ContentState;
 import org.zanata.common.LocaleId;
 import org.zanata.common.ProjectType;
@@ -50,6 +44,8 @@
 import lombok.extern.slf4j.Slf4j;
 
 /**
+ * Entity event listener for HTextFlowTarget.
+ *
  * @author Patrick Huang <a
  *         href="mailto:pahuang@redhat.com">pahuang@redhat.com</a>
  */
@@ -61,16 +57,24 @@ public class TranslationUpdateListener implements PostUpdateEventListener,
         PostInsertEventListener {
 
     private static final long serialVersionUID = 1L;
+
     private static final Cache<CacheKey, CacheValue> updateContext =
             CacheBuilder.newBuilder().softValues()
-                    .expireAfterAccess(1, TimeUnit.SECONDS).build();
+                    .expireAfterAccess(1, TimeUnit.SECONDS).maximumSize(1000)
+                    .build();
 
     @In(create = true)
     private TranslationWorkspaceManager translationWorkspaceManager;
 
     @In
     private TransUnitTransformer transUnitTransformer;
 
+    /**
+     * Event raised by Text flow target update initiator containing update
+     * context.
+     *
+     * @param event
+     */
     @Observer(TextFlowTargetUpdateContextEvent.EVENT_NAME)
     public static void updateContext(TextFlowTargetUpdateContextEvent event) {
         updateContext
@@ -97,7 +101,7 @@ protected Void work() throws Exception {
 
                     HTextFlowTarget target =
                             HTextFlowTarget.class.cast(event.getEntity());
-                    publishTransUnitUpdatedEvent(target.getVersionNum() - 1,
+                    prepareTransUnitUpdatedEvent(target.getVersionNum() - 1,
                             oldContentState, target);
                     return null;
                 }
@@ -108,7 +112,7 @@ protected Void work() throws Exception {
 
     }
 
-    private void publishTransUnitUpdatedEvent(int previousVersionNum,
+    private void prepareTransUnitUpdatedEvent(int previousVersionNum,
             ContentState previousState, HTextFlowTarget target) {
         LocaleId localeId = target.getLocaleId();
         HTextFlow textFlow = target.getTextFlow();
@@ -144,25 +148,30 @@ private void publishTransUnitUpdatedEvent(int previousVersionNum,
                         transUnit.getLocaleId()));
         TransUnitUpdated updated;
         if (context != null) {
-            EditorClientId editorClientId = context.editorClientId;
-            TransUnitUpdated.UpdateType updateType = context.updateType;
             updated =
-                    new TransUnitUpdated(updateInfo, editorClientId, updateType);
+                    new TransUnitUpdated(updateInfo, context.editorClientId,
+                            context.updateType);
             log.debug("about to publish trans unit updated event {}", updated);
         } else if (ServletContexts.instance().getRequest() != null) {
 
-            String sessionId = ServletContexts.instance().getRequest().getSession()
-                    .getId();
+            String sessionId =
+                    ServletContexts.instance().getRequest().getSession()
+                            .getId();
             EditorClientId editorClientId = new EditorClientId(sessionId, -1);
-            updated = new TransUnitUpdated(updateInfo, editorClientId,
+            updated =
+                    new TransUnitUpdated(updateInfo, editorClientId,
                             TransUnitUpdated.UpdateType.NonEditorSave);
         } else {
-            updated = new TransUnitUpdated(updateInfo, new EditorClientId("unknown", -1),
-                    TransUnitUpdated.UpdateType.NonEditorSave);
+            updated =
+                    new TransUnitUpdated(updateInfo, new EditorClientId(
+                            "unknown", -1),
+                            TransUnitUpdated.UpdateType.NonEditorSave);
         }
         if (Events.exists()) {
             Events.instance().raiseTransactionSuccessEvent(
-                    TextFlowTargetUpdatedEvent.EVENT_NAME, new TextFlowTargetUpdatedEvent(workspaceOptional.get(), target.getId(), updated));
+                    TextFlowTargetUpdatedEvent.EVENT_NAME,
+                    new TextFlowTargetUpdatedEvent(workspaceOptional.get(),
+                            target.getId(), updated));
         }
     }
 
@@ -186,7 +195,7 @@ public void onPostInsert(final PostInsertEvent event) {
                 protected Void work() throws Exception {
                     HTextFlowTarget target =
                             HTextFlowTarget.class.cast(event.getEntity());
-                    publishTransUnitUpdatedEvent(0, ContentState.New, target);
+                    prepareTransUnitUpdatedEvent(0, ContentState.New, target);
                     return null;
                 }
             }.workInTransaction();