Merge pull request #178 from teamterning/refactor/#177

[♻️ refactor] N+1 문제 해결 및 HomeServiceImpl 성능 개선
teamterning · Dec 11, 2024 · e413bf1 · e413bf1
2 parents 6437e37 + 08bbfe5
commit e413bf1
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Showing 3 changed files with 337 additions and 27 deletions.
diff --git a/...rg/terning/terningserver/repository/internship_announcement/InternshipRepositoryImpl.java b/...rg/terning/terningserver/repository/internship_announcement/InternshipRepositoryImpl.java
@@ -81,27 +81,6 @@ public Page<InternshipAnnouncement> searchInternshipAnnouncement(String keyword,
         return PageableExecutionUtils.getPage(internshipAnnouncements, pageable, count::fetchOne);
     }
 
-    @Override
-    public List<Tuple> findFilteredInternshipsWithScrapInfo(User user, String sortBy, int startYear, int startMonth) {
-        return jpaQueryFactory
-                .select(
-                        internshipAnnouncement,
-                        scrap.id,
-                        scrap.color
-                )
-                .from(internshipAnnouncement)
-                .leftJoin(internshipAnnouncement.scraps, scrap).on(scrap.user.eq(user)) // Fetch Join
-                .where(
-                        getGraduatingFilter(user),
-                        getWorkingPeriodFilter(user),
-                        getStartDateFilter(startYear, startMonth)
-                )
-                .orderBy(
-                        sortAnnouncementsByDeadline().asc(),
-                        getSortOrder(sortBy)
-                )
-                .fetch();
-    }
 
     private boolean isPureEnglish(String summonerName) {
         //공백은 무시
@@ -129,7 +108,24 @@ private OrderSpecifier createOrderSpecifier(String sortBy) {
         };
     }
 
-
+    @Override
+    public List<Tuple> findFilteredInternshipsWithScrapInfo(User user, String sortBy, int startYear, int startMonth){
+        return jpaQueryFactory
+                .select(internshipAnnouncement, scrap.id, scrap.color) // tuple -> Scrap 정보 한번에 불러오기
+                .from(internshipAnnouncement)
+                .leftJoin(internshipAnnouncement.scraps, scrap).on(scrap.user.eq(user))
+                .where(
+                        getGraduatingFilter(user),
+                        getWorkingPeriodFilter(user),
+                        getStartDateFilter(startYear, startMonth)
+                )
+                .orderBy(
+                        sortAnnouncementsByDeadline().asc(),
+                        getSortOrder(sortBy)
+                )
+                .fetch();
+    }
+
     private BooleanExpression getGraduatingFilter(User user){
         if(user.getFilter().getGrade() != Grade.SENIOR){
             return internshipAnnouncement.isGraduating.isFalse();

diff --git a/src/main/java/org/terning/terningserver/service/HomeServiceImpl.java b/src/main/java/org/terning/terningserver/service/HomeServiceImpl.java
@@ -6,6 +6,7 @@
 import org.springframework.transaction.annotation.Transactional;
 import org.terning.terningserver.domain.InternshipAnnouncement;
 import org.terning.terningserver.domain.User;
+import org.terning.terningserver.domain.enums.Color;
 import org.terning.terningserver.dto.user.response.HomeAnnouncementsResponseDto;
 import org.terning.terningserver.dto.user.response.HomeResponseDto;
 import org.terning.terningserver.exception.CustomException;
@@ -32,20 +33,29 @@ public HomeAnnouncementsResponseDto getAnnouncements(Long userId, String sortBy,
                 () -> new CustomException(ErrorMessage.NOT_FOUND_USER_EXCEPTION)
         );
 
+        // 유저의 필터 정보가 없는 경우
         if(user.getFilter() == null){
             return HomeAnnouncementsResponseDto.of(0,List.of());
         }
 
-        List<Tuple> results = internshipRepository.findFilteredInternshipsWithScrapInfo(user, sortBy, startYear, startMonth);
+        List<Tuple> announcements = internshipRepository.findFilteredInternshipsWithScrapInfo(user, sortBy, startYear, startMonth);
 
-        List<HomeResponseDto> responseDtos = results.stream()
+        // 해당하는 공고가 없는 경우
+        if(announcements.isEmpty()){
+            return HomeAnnouncementsResponseDto.of(0, List.of());
+        }
+
+        List<HomeResponseDto> responseDtos = announcements.stream()
                 .map(tuple -> {
                     InternshipAnnouncement announcement = tuple.get(internshipAnnouncement);
                     Long scrapId = tuple.get(scrap.id);
-                    String color = tuple.get(scrap.color.stringValue());
+                    Color color = tuple.get(scrap.color);
+                    boolean isScrapped = (scrapId != null); // 스크랩 여부
+
+                    // scrap 하지 않은 경우 color는 지정되지 않아야 한다.
+                    String colorValue = (isScrapped && color != null) ? color.getColorValue() : null;
 
-                    boolean isScrapped = isScrapped(scrapId);
-                    return HomeResponseDto.of(announcement, isScrapped, color);
+                    return HomeResponseDto.of(announcement, isScrapped, colorValue);
                 })
                 .toList();