OO-634: hardened publisher update to the cost of a query

src/main/java/org/olat/notifications/NotificationsManagerImpl.java

@@ -594,42 +594,45 @@ public class NotificationsManagerImpl extends NotificationsManager implements Us
 	 */
 	@Override
 	public Publisher getPublisher(SubscriptionContext subsContext) {
-		return getPublisher(subsContext.getResName(), subsContext.getResId(), subsContext.getSubidentifier(), false);
-	}
-	
-	private Publisher getPublisherForUpdate(SubscriptionContext subsContext) {
-		return getPublisher(subsContext.getResName(), subsContext.getResId(), subsContext.getSubidentifier(), true);
-	}
-	
-	@Override
-	public List<Publisher> getAllPublisher() {
-		String q = "select pub from org.olat.notifications.PublisherImpl pub";
-		return DBFactory.getInstance().getCurrentEntityManager().createQuery(q, Publisher.class)
-				.getResultList();
-	}
-	
-	/**
-	 * return the publisher for the given composite primary key ores +
-	 * subidentifier.
-	 */
-	private Publisher getPublisher(String resName, Long resId, String subidentifier, boolean forUpdate) {
 		StringBuilder q = new StringBuilder();
 		q.append("select pub from ").append(PublisherImpl.class.getName()).append(" pub ")
-		 .append(" where pub.resName=:resName and pub.resId = :resId and pub.subidentifier = :subidentifier");
+		 .append(" where pub.resName=:resName and pub.resId = :resId");
+		if(StringHelper.containsNonWhitespace(subsContext.getSubidentifier())) {
+			q.append(" and pub.subidentifier=:subidentifier");
+		} else {
+			q.append(" and (pub.subidentifier='' or pub.subidentifier is null)");
+		}
 		
 		TypedQuery<Publisher> query = DBFactory.getInstance().getCurrentEntityManager()
 				.createQuery(q.toString(), Publisher.class)
-				.setParameter("resName", resName)
-				.setParameter("resId", resId.longValue())
-				.setParameter("subidentifier", subidentifier);
-		if(forUpdate) {
-			query.setLockMode(LockModeType.PESSIMISTIC_WRITE);
+				.setParameter("resName", subsContext.getResName())
+				.setParameter("resId", subsContext.getResId());
+
+		if(StringHelper.containsNonWhitespace(subsContext.getSubidentifier())) {
+			query.setParameter("subidentifier", subsContext.getSubidentifier());
 		}
 		List<Publisher> res = query.getResultList();
 		if (res.isEmpty()) return null;
 		if (res.size() != 1) throw new AssertException("only one subscriber per person and publisher!!");
 		return res.get(0);
 	}
+	
+	private Publisher getPublisherForUpdate(SubscriptionContext subsContext) {
+		Publisher pub = getPublisher(subsContext);
+		if(pub != null && pub.getKey() != null) {
+			//prevent optimistic lock issue
+			DBFactory.getInstance().getCurrentEntityManager().detach(pub);
+			pub = DBFactory.getInstance().getCurrentEntityManager().find(PublisherImpl.class, pub.getKey(), LockModeType.PESSIMISTIC_WRITE);
+		}
+		return pub;
+	}
+	
+	@Override
+	public List<Publisher> getAllPublisher() {
+		String q = "select pub from org.olat.notifications.PublisherImpl pub";
+		return DBFactory.getInstance().getCurrentEntityManager().createQuery(q, Publisher.class)
+				.getResultList();
+	}
 
 	/**
 	 * @param resName
@@ -838,7 +841,7 @@ public class NotificationsManagerImpl extends NotificationsManager implements Us
 		// to make sure: ignore if no subscriptionContext
 		if (subscriptionContext == null) return;
 
-		Publisher toUpdate = getPublisher(subscriptionContext.getResName(), subscriptionContext.getResId(), subscriptionContext.getSubidentifier(), true);
+		Publisher toUpdate = getPublisherForUpdate(subscriptionContext);
 		if(toUpdate == null) {
 			return;
 		}