Merge pull request #289 from spring-team-7/feat/event

[refactor] 이벤트 참여 DB 락 로직 수정

Author: 3uomlkh

src/main/java/org/example/tablenow/domain/event/entity/Event.java

@@ -43,6 +43,9 @@ public class Event extends TimeStamped {
     @Column(nullable = false)
     private int limitPeople;
 
+    @Column(nullable = false)
+    private int availableSeats;
+
     @Enumerated(EnumType.STRING)
     @Column(nullable = false)
     private EventStatus status;
@@ -55,13 +58,25 @@ private Event(Store store, String content, LocalDateTime openAt, LocalDateTime e
         this.endAt = endAt;
         this.eventTime = eventTime;
         this.limitPeople = limitPeople;
+        this.availableSeats = limitPeople;
         this.status = EventStatus.READY;
     }
 
     public void update(LocalDateTime openAt, LocalDateTime eventTime, Integer limitPeople) {
         if (openAt != null) this.openAt = openAt;
         if (eventTime != null) this.eventTime = eventTime;
-        if (limitPeople != null) this.limitPeople = limitPeople;
+        if (limitPeople != null) {
+            this.limitPeople = limitPeople;
+            this.availableSeats = limitPeople;
+        }
+    }
+
+    public void decreaseAvailableSeats() {
+        if (this.availableSeats > 0) {
+            this.availableSeats--;
+        } else {
+            throw new HandledException(ErrorCode.EVENT_FULL);
+        }
     }
 
     public boolean isReady() {

src/main/java/org/example/tablenow/domain/event/repository/EventRepository.java

@@ -8,14 +8,16 @@
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Lock;
 import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.time.LocalDateTime;
 import java.util.Optional;
 
 public interface EventRepository extends JpaRepository<Event, Long> {
     boolean existsByStore_IdAndEventTime(Long storeId, LocalDateTime eventTime);
     Page<Event> findByStatus(EventStatus status, Pageable pageable);
+
     @Lock(LockModeType.PESSIMISTIC_WRITE)
     @Query("SELECT e FROM Event e WHERE e.id = :id")
-    Optional<Event> findByIdForUpdate(Long id);
+    Optional<Event> findByIdForUpdate(@Param("id") Long id);
 }

src/main/java/org/example/tablenow/domain/event/service/EventJoinService.java

@@ -62,9 +62,8 @@ public EventJoinResponseDto joinEventWithDBLock(Long eventId, AuthUser authUser)
             throw new HandledException(ErrorCode.EVENT_ALREADY_JOINED);
         }
 
-        if (eventJoinRepository.countByEvent(event) >= event.getLimitPeople()) {
-            throw new HandledException(ErrorCode.EVENT_FULL);
-        }
+        event.decreaseAvailableSeats();
+        eventRepository.save(event);
 
         EventJoin eventJoin = EventJoin.builder()
                 .user(user)