From ea65d1e81ccf712c0d33780b87a5ed8abd9cb01c Mon Sep 17 00:00:00 2001
From: anhefti <andreas.hefti@let.ethz.ch>
Date: Wed, 27 Oct 2021 09:11:00 +0200
Subject: [PATCH] code analysis

---
 .../sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java | 1 +
 .../servicelayer/session/impl/ExamSessionServiceImpl.java       | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java
index a258846e..f10e325c 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/ExamDAOImpl.java
@@ -637,6 +637,7 @@ public class ExamDAOImpl implements ExamDAO {
     @Override
     @Transactional(readOnly = true)
     public Result<Boolean> upToDate(final Long examId, final String updateId) {
+        // TODO make this with count on examId and updateId equals --> if count is 1 then it is up to date otherwise not
         return this.recordById(examId)
                 .map(rec -> {
                     if (updateId == null) {
diff --git a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
index 67a62448..8c29fe3c 100644
--- a/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
+++ b/src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamSessionServiceImpl.java
@@ -361,11 +361,13 @@ public class ExamSessionServiceImpl implements ExamSessionService {
 
     @Override
     public Result<Exam> updateExamCache(final Long examId) {
+        // Get from cache (or load to cache if not already present)
         final Exam exam = this.examSessionCacheService.getRunningExam(examId);
         if (exam == null) {
             return Result.ofEmpty();
         }
 
+        // Check if the exam from cache is up to date by checking the last_update on persistent storage
         final Boolean isUpToDate = this.examDAO.upToDate(examId, exam.lastUpdate)
                 .onError(t -> log.error("Failed to verify if cached exam is up to date: {}", exam, t))
                 .getOr(false);