refactor: 다이어리 생성 시 geohash 문자열 저장 기능 추가

- Look-Aside 전략에 따라 생성 시 캐시에는 저장하지 않음

Author: dnzp75

src/main/java/com/example/log4u/domain/diary/facade/DiaryFacade.java

@@ -13,6 +13,7 @@
 import com.example.log4u.domain.diary.dto.PopularDiaryDto;
 import com.example.log4u.domain.diary.entity.Diary;
 import com.example.log4u.domain.diary.service.DiaryService;
+import com.example.log4u.domain.diary.service.DiaryGeohashService;
 import com.example.log4u.domain.hashtag.service.HashtagService;
 import com.example.log4u.domain.like.service.LikeService;
 import com.example.log4u.domain.map.service.MapService;
@@ -33,6 +34,7 @@ public class DiaryFacade {
 	private final LikeService likeService;
 	private final HashtagService hashtagService;
 	private final UserService userService;
+	private final DiaryGeohashService diaryGeohashService;
 
 	/**
 	 * 다이어리 생성 use case
@@ -41,23 +43,30 @@ public class DiaryFacade {
 	 * 2. diaryService: 다이어리 생성<br>
 	 * 2. mediaService: 해당 다이어리의 이미지 저장<br>
 	 * 3. mapService: 해당 구역 카운트 증가
+	 * 4. diaryGeohashService: 해당 다이어리 위치가 포함되어있는 geoHash 문자열 저장
 	 * */
 	@Transactional
 	public void createDiary(Long userId, DiaryRequestDto request) {
 		String thumbnailUrl = mediaService.extractThumbnailUrl(request.mediaList());
 		Diary diary = diaryService.saveDiary(userId, request, thumbnailUrl);
 		mediaService.saveMedia(diary.getDiaryId(), request.mediaList());
 		hashtagService.saveOrUpdateHashtag(diary.getDiaryId(), request.hashtagList());
-		mapService.increaseRegionDiaryCount(request.location().latitude(), request.location().longitude());
+
+		double lat = request.location().latitude();
+		double lon = request.location().longitude();
+		mapService.increaseRegionDiaryCount(lat, lon);
+		diaryGeohashService.saveGeohash(diary.getDiaryId(), lat, lon);
 	}
 
 	/**
 	 * 다이어리 삭제 use case
 	 * <ul><li>호출 과정</li></ul>
 	 * 1. diaryService: 다이어리 검증
 	 * 2. mediaService: 해당 다이어리 이미지 삭제<br>
-	 * 3. diaryService: 다이어리 삭제<br>
-	 * 4. mapService: 해당 구역 카운트 감소
+	 * 3. mapService: 해당 구역 카운트 감소
+	 * 4. diaryGeohashService: 캐싱 되어있는 id, 데이터 삭제
+	 * 5. diaryService: 다이어리 삭제<br>
+	 *
 	 * */
 	@Transactional
 	public void deleteDiary(Long userId, Long diaryId) {
@@ -66,6 +75,7 @@ public void deleteDiary(Long userId, Long diaryId) {
 		hashtagService.deleteHashtagsByDiaryId(diaryId);
 		mapService.decreaseRegionDiaryCount(diary.getLocation().getLatitude(), diary.getLocation().getLongitude());
 
+		diaryGeohashService.deleteGeohashAndCache(diaryId);
 		diaryService.deleteDiary(diary);
 	}
 

src/main/java/com/example/log4u/domain/diary/service/DiaryGeohashService.java

@@ -0,0 +1,46 @@
+package com.example.log4u.domain.diary.service;
+
+import java.util.List;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.example.log4u.domain.diary.entity.DiaryGeoHash;
+import com.example.log4u.domain.diary.repository.DiaryGeoHashRepository;
+import com.example.log4u.domain.map.cache.dao.DiaryCacheDao;
+
+import ch.hsr.geohash.GeoHash;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class DiaryGeohashService {
+
+	private final DiaryGeoHashRepository diaryGeoHashRepository;
+	private final DiaryCacheDao diaryCacheDao;
+
+	@Transactional
+	public void saveGeohash(Long diaryId, double lat, double lon) {
+		String hash = GeoHash.withCharacterPrecision(lat, lon, 5).toBase32();
+		DiaryGeoHash diaryGeoHash = DiaryGeoHash.builder()
+			.diaryId(diaryId)
+			.geohash(hash)
+			.build();
+		diaryGeoHashRepository.save(diaryGeoHash);
+	}
+
+	@Transactional
+	public void deleteGeohashAndCache(Long diaryId) {
+		DiaryGeoHash geoHash = diaryGeoHashRepository.findByDiaryId(diaryId);
+		diaryCacheDao.evictDiaryIdFromCache(geoHash.getGeohash(), diaryId);
+		diaryCacheDao.evictDiaryFromCache(diaryId);
+
+		diaryGeoHashRepository.deleteById(diaryId);
+	}
+
+	public List<Long> getDiaryIdsByGeohash(String geohash) {
+		return diaryGeoHashRepository.findDiaryIdByGeohash(geohash);
+	}
+}