From 0574f4f6290ec365c2308e37ae3fc70cae1fa23c Mon Sep 17 00:00:00 2001
From: Klaus <klaus@vividnext.co.kr>
Date: Sun, 14 Sep 2025 17:43:53 +0900
Subject: [PATCH] =?UTF-8?q?feat(cache):=20=EC=9D=B8=EA=B8=B0=20=EC=BA=90?=
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- ChatCharacterService.getPopularCharacters()에 @Cacheable 추가
- 키: popular-chat-character:<windowStartEpoch>:<limit>
- 윈도우(매일 20:00 UTC) 전환 시 자동으로 신규 키 사용 → 전일 순위 캐시와 분리 보장

Why: 동일 윈도우 내 반복 요청의 DB 부하를 줄이고, 경계 전환 시 자연스러운 캐시 갱신을 보장.
---
 .../chat/character/service/ChatCharacterService.kt     |  5 +++++
 .../kr/co/vividnext/sodalive/configs/RedisConfig.kt    | 10 ++++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/main/kotlin/kr/co/vividnext/sodalive/chat/character/service/ChatCharacterService.kt b/src/main/kotlin/kr/co/vividnext/sodalive/chat/character/service/ChatCharacterService.kt
index e48bf21..ea0f5c1 100644
--- a/src/main/kotlin/kr/co/vividnext/sodalive/chat/character/service/ChatCharacterService.kt
+++ b/src/main/kotlin/kr/co/vividnext/sodalive/chat/character/service/ChatCharacterService.kt
@@ -19,6 +19,7 @@ import kr.co.vividnext.sodalive.chat.character.repository.ChatCharacterRepositor
 import kr.co.vividnext.sodalive.chat.character.repository.ChatCharacterTagRepository
 import kr.co.vividnext.sodalive.chat.character.repository.ChatCharacterValueRepository
 import org.springframework.beans.factory.annotation.Value
+import org.springframework.cache.annotation.Cacheable
 import org.springframework.data.domain.PageRequest
 import org.springframework.data.domain.Sort
 import org.springframework.stereotype.Service
@@ -42,6 +43,10 @@ class ChatCharacterService(
      * Spring Cache(@Cacheable) + 동적 키 + 고정 TTL(24h) 사용
      */
     @Transactional(readOnly = true)
+    @Cacheable(
+        cacheNames = ["popularCharacters_24h"],
+        key = "T(kr.co.vividnext.sodalive.chat.character.service.RankingWindowCalculator).now('popular-chat-character').cacheKey"
+    )
     fun getPopularCharacters(limit: Long = 20): List<Character> {
         val window = RankingWindowCalculator.now("popular-chat-character")
         val topIds = popularCharacterQuery.findPopularCharacterIds(window.windowStart, window.nextBoundary, limit)
diff --git a/src/main/kotlin/kr/co/vividnext/sodalive/configs/RedisConfig.kt b/src/main/kotlin/kr/co/vividnext/sodalive/configs/RedisConfig.kt
index 04a6c2c..eea5eab 100644
--- a/src/main/kotlin/kr/co/vividnext/sodalive/configs/RedisConfig.kt
+++ b/src/main/kotlin/kr/co/vividnext/sodalive/configs/RedisConfig.kt
@@ -123,6 +123,16 @@ class RedisConfig(
                 )
             )
 
+        // 24시간 TTL 캐시: 인기 캐릭터 집계용
+        cacheConfigMap["popularCharacters_24h"] = RedisCacheConfiguration.defaultCacheConfig()
+            .entryTtl(Duration.ofHours(24))
+            .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(StringRedisSerializer()))
+            .serializeValuesWith(
+                RedisSerializationContext.SerializationPair.fromSerializer(
+                    GenericJackson2JsonRedisSerializer()
+                )
+            )
+
         return RedisCacheManager.builder(redisConnectionFactory)
             .cacheDefaults(defaultCacheConfig)
             .withInitialCacheConfigurations(cacheConfigMap)