Merge pull request #99 from NMNB-Team/v1/fix/#98-change-invalidate-cache

[refactor] 캐시 만료 시간 제거 및 조건부 재설정으로 변경

Author: 88dldl

nmnb-application/src/main/kotlin/nmnb/application/domain/post/service/PostCacheEvictor.kt

@@ -0,0 +1,15 @@
+package nmnb.application.domain.post.service
+
+import org.springframework.cache.annotation.CacheEvict
+import org.springframework.stereotype.Service
+
+@Service
+class PostCacheEvictor() {
+    @CacheEvict(cacheNames = ["postIds"])
+    fun refreshPostIds() {
+    }
+
+    @CacheEvict(cacheNames = ["shuffledIds"], key = "#seed")
+    fun refreshShuffledIds(seed: Int) {
+    }
+}

nmnb-application/src/main/kotlin/nmnb/application/domain/post/service/PostCacheService.kt

@@ -1,6 +1,9 @@
 package nmnb.application.domain.post.service
 
+import nmnb.application.domain.post.service.dto.request.PostPageServiceRequest
+
 interface PostCacheService {
     fun getAllPostIds(): List<Long>
     fun getShuffledIds(ids: List<Long>, seed: Int): List<Long>
+    fun refreshPostcache(request: PostPageServiceRequest)
 }

nmnb-application/src/main/kotlin/nmnb/application/domain/post/service/PostCacheServiceImpl.kt

@@ -1,5 +1,6 @@
 package nmnb.application.domain.post.service
 
+import nmnb.application.domain.post.service.dto.request.PostPageServiceRequest
 import nmnb.application.domain.post.utils.RandomSelector
 import nmnb.domain.post.repository.PostRepository
 import org.springframework.cache.annotation.Cacheable
@@ -8,6 +9,7 @@ import org.springframework.stereotype.Service
 @Service
 class PostCacheServiceImpl(
     private val postRepository: PostRepository,
+    private val postCacheEvictor: PostCacheEvictor,
 ) : PostCacheService {
     @Cacheable(cacheNames = ["postIds"])
     override fun getAllPostIds(): List<Long> = postRepository.findAllPostId()
@@ -16,4 +18,15 @@ class PostCacheServiceImpl(
     override fun getShuffledIds(ids: List<Long>, seed: Int): List<Long> {
         return RandomSelector.shuffleIds(ids, seed)
     }
+
+    override fun refreshPostcache(request: PostPageServiceRequest) {
+        if (request.cursor == INITIAL_CURSOR) {
+            postCacheEvictor.refreshPostIds()
+            postCacheEvictor.refreshShuffledIds(request.seed)
+        }
+    }
+
+    companion object {
+        private const val INITIAL_CURSOR = -1
+    }
 }

nmnb-application/src/main/kotlin/nmnb/application/domain/post/service/PostServiceImpl.kt

@@ -16,6 +16,7 @@ class PostServiceImpl(
     private val postCacheService: PostCacheService,
 ) : PostService {
     override fun getPostPage(request: PostPageServiceRequest): PostPageResponse {
+        postCacheService.refreshPostcache(request)
         val allPostIds = postCacheService.getAllPostIds()
         val shuffledPostIds = postCacheService.getShuffledIds(allPostIds, request.seed)
 
@@ -32,7 +33,7 @@ class PostServiceImpl(
     ): PostPageResponse {
         val postsInfoResponse = mapPostsToResponse(pageIds)
         val hasNext = shuffledPostIds.size > (startIndex + pageIds.size)
-        val nextCursor = if (!hasNext) -1 else startIndex + pageIds.size - 1
+        val nextCursor = if (!hasNext) INITIAL_CURSOR else startIndex + pageIds.size - 1
 
         return PostPageResponse.of(postsInfoResponse, hasNext, nextCursor)
     }
@@ -48,4 +49,8 @@ class PostServiceImpl(
         val posts = postRepository.findAllByIdIn(pageIds)
         return posts.associateBy { it.id!! }
     }
+
+    companion object {
+        private const val INITIAL_CURSOR = -1
+    }
 }

nmnb-application/src/main/kotlin/nmnb/application/global/config/CacheConfig.kt

@@ -6,7 +6,6 @@ import org.springframework.cache.annotation.EnableCaching
 import org.springframework.cache.caffeine.CaffeineCacheManager
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
-import java.util.concurrent.TimeUnit
 
 @EnableCaching
 @Configuration
@@ -16,7 +15,6 @@ class CacheConfig {
         val cacheManager = CaffeineCacheManager()
         cacheManager.setCaffeine(
             Caffeine.newBuilder()
-                .expireAfterWrite(10, TimeUnit.MINUTES)
                 .maximumSize(100),
         )
         return cacheManager

nmnb-application/src/test/kotlin/nmnb/application/domain/post/service/PostCacheServiceTest.kt

@@ -1,8 +1,10 @@
 package nmnb.application.domain.post.service
 
 import nmnb.application.IntegrationTestSupport
+import nmnb.application.domain.post.service.dto.request.PostPageServiceRequest
 import nmnb.domain.post.repository.PostRepository
 import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.extension.ExtendWith
@@ -20,11 +22,19 @@ class PostCacheServiceTest(
     @Autowired
     var postCacheService: PostCacheService,
     @Autowired
+    var postCacheEvictor: PostCacheEvictor,
+    @Autowired
     var cacheManager: CacheManager,
 ) : IntegrationTestSupport() {
     @MockBean
     lateinit var postRepository: PostRepository
 
+    @AfterEach
+    fun tearDown() {
+        cacheManager.getCache("postIds")?.clear()
+        cacheManager.getCache("shuffledIds")?.clear()
+    }
+
     @DisplayName("getAllPostIds 메서드는 캐시에 저장되며, 두 번째 호출부터는 캐시된 값이 반환된다")
     @Test
     fun getAllPostIdsWithCache() {
@@ -64,4 +74,27 @@ class PostCacheServiceTest(
         assertThat(result1).isEqualTo(result2)
         assertThat(result1).isNotEqualTo(result3)
     }
+
+    @DisplayName("캐시를 무효화하는데 성공한다.")
+    @Test
+    fun refreshCache() {
+        // given
+        val ids = listOf(1L, 2L, 3L, 4L, 5L)
+        whenever(postRepository.findAllPostId()).thenReturn(ids)
+        val seed = 1234
+        val request = PostPageServiceRequest(seed = seed, cursor = -1, size = 7)
+
+        postCacheService.getAllPostIds()
+        postCacheService.getShuffledIds(ids, seed)
+
+        assertThat(cacheManager.getCache("postIds")?.get(SimpleKey.EMPTY)).isNotNull
+        assertThat(cacheManager.getCache("shuffledIds")?.get(seed)).isNotNull
+
+        // when
+        postCacheService.refreshPostcache(request)
+
+        // then
+        assertThat(cacheManager.getCache("postIds")?.get(SimpleKey.EMPTY)).isNull()
+        assertThat(cacheManager.getCache("shuffledIds")?.get(seed)).isNull()
+    }
 }

nmnb-application/src/test/kotlin/nmnb/application/domain/post/service/PostServiceImplTest.kt

@@ -10,7 +10,11 @@ import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
+import org.mockito.kotlin.never
+import org.mockito.kotlin.times
+import org.mockito.kotlin.verify
 import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.mock.mockito.MockBean
 import org.springframework.cache.CacheManager
 import org.springframework.transaction.annotation.Transactional
 
@@ -22,6 +26,9 @@ class PostServiceImplTest(
     @Autowired private var cacheManager: CacheManager,
 ) : IntegrationTestSupport() {
 
+    @MockBean
+    private lateinit var postCacheEvictor: PostCacheEvictor
+
     @AfterEach
     fun tearDown() {
         postRepository.deleteAllInBatch()
@@ -89,4 +96,32 @@ class PostServiceImplTest(
         // then
         assertThat(result.nextCursor).isEqualTo(-1)
     }
+
+    @DisplayName("조회 커서가 초기 값(-1)일 경우 캐시가 무효화된다.")
+    @Test
+    fun refreshCacheWhenInitialCursor() {
+        // given
+        val seed = 1234
+        val request = PostPageServiceRequest(seed = seed, cursor = -1, size = 7)
+
+        // when
+        postService.getPostPage(request)
+
+        // then
+        verify(postCacheEvictor, times(1)).refreshPostIds()
+    }
+
+    @DisplayName("조회 커서가 초기 값(-1)이 아닐 경우 캐시가 무효화되지 않는다.")
+    @Test
+    fun refreshCacheWhenNotInitialCursor() {
+        // given
+        val seed = 1234
+        val request = PostPageServiceRequest(seed = seed, cursor = 1, size = 7)
+
+        // when
+        postService.getPostPage(request)
+
+        // then
+        verify(postCacheEvictor, never()).refreshPostIds()
+    }
 }