Fix: N+1문제 해결

src/cardset/application/cardset.use-case.ts

@@ -161,24 +161,22 @@ export class CardsetUseCase {
       category: req.category,
     });
 
-    const visibleCardsets: Cardset[] = [];
-    for (const cardset of items) {
-      if (cardset.visibility === Visibility.PUBLIC) {
-        visibleCardsets.push(cardset);
-        continue;
-      }
-      if (isNaN(userId)) continue;
+    const hasPrivate = items.some((c) => c.visibility !== Visibility.PUBLIC);
+    let myGroupIds = new Set<number>();
+    if (hasPrivate && !isNaN(userId)) {
       try {
-        const inGroup = await this.groupGrpcClient.isUserInGroup(
-          cardset.groupId,
-          userId,
+        myGroupIds = await this.groupGrpcClient.getMyGroupIds(userId);
+      } catch (err) {
+        this.logger.error(
+          `[findAllPaged] 그룹 목록 조회 실패 (userId=${userId}): ${err instanceof Error ? err.message : String(err)}`,
         );
-        if (inGroup) visibleCardsets.push(cardset);
-      } catch {
-        // 그룹 조회 실패 시 해당 카드셋 제외
       }
     }
 
+    const visibleCardsets = items.filter(
+      (c) => c.visibility === Visibility.PUBLIC || myGroupIds.has(c.groupId),
+    );
+
     const ids = visibleCardsets.map((c) => c.id);
 
     if (ids.length === 0) {
@@ -237,23 +235,20 @@ export class CardsetUseCase {
     }[]
   > {
     const cardsets = await this.cardsetRepository.findAll();
-    const visibleCardsets: Cardset[] = [];
-    for (const cardset of cardsets) {
-      if (cardset.visibility === Visibility.PUBLIC) {
-        visibleCardsets.push(cardset);
-        continue;
-      }
-      if (isNaN(userId)) continue;
+    const hasPrivate = cardsets.some((c) => c.visibility !== Visibility.PUBLIC);
+    let myGroupIds = new Set<number>();
+    if (hasPrivate && !isNaN(userId)) {
       try {
-        const inGroup = await this.groupGrpcClient.isUserInGroup(
-          cardset.groupId,
-          userId,
+        myGroupIds = await this.groupGrpcClient.getMyGroupIds(userId);
+      } catch (err) {
+        this.logger.error(
+          `[findAll] 그룹 목록 조회 실패 (userId=${userId}): ${err instanceof Error ? err.message : String(err)}`,
         );
-        if (inGroup) visibleCardsets.push(cardset);
-      } catch {
-        // 그룹 조회 실패 시 해당 카드셋 제외
       }
     }
+    const visibleCardsets = cardsets.filter(
+      (c) => c.visibility === Visibility.PUBLIC || myGroupIds.has(c.groupId),
+    );
 
     const ids = visibleCardsets.map((c) => c.id);
     const [metadataMap, likedMap, bookmarkedMap, managersMap] =
@@ -536,19 +531,20 @@ export class CardsetUseCase {
     userId: number,
   ): Promise<Cardset[]> {
     const cardsets = await this.cardsetRepository.findByIds(cardSetIds);
-    const viewable: Cardset[] = [];
-    for (const cardset of cardsets) {
-      if (cardset.visibility === Visibility.PUBLIC) {
-        viewable.push(cardset);
-      } else {
-        const inGroup = await this.groupGrpcClient.isUserInGroup(
-          cardset.groupId,
-          userId,
+    const hasPrivate = cardsets.some((c) => c.visibility !== Visibility.PUBLIC);
+    let myGroupIds = new Set<number>();
+    if (hasPrivate && !isNaN(userId)) {
+      try {
+        myGroupIds = await this.groupGrpcClient.getMyGroupIds(userId);
+      } catch (err) {
+        this.logger.error(
+          `[getCardSetsByIds] 그룹 목록 조회 실패 (userId=${userId}): ${err instanceof Error ? err.message : String(err)}`,
         );
-        if (inGroup) viewable.push(cardset);
       }
     }
-    return viewable;
+    return cardsets.filter(
+      (c) => c.visibility === Visibility.PUBLIC || myGroupIds.has(c.groupId),
+    );
   }
 
   async updateCardCount(

src/cardset/infrastructure/grpc/group-grpc.client.ts

@@ -9,6 +9,7 @@ interface GroupCommandService {
     groupId: number;
     userId: number;
   }): Observable<{ exists: boolean }>;
+  getMyGroup(data: { userId: number }): Observable<{ groupId: number[] }>;
 }
 
 @Injectable()
@@ -40,4 +41,13 @@ export class GroupGrpcClient implements OnModuleInit {
     );
     return result.exists;
   }
+
+  async getMyGroupIds(userId: number): Promise<Set<number>> {
+    console.log('[getMyGroupIds] request userId:', userId);
+    const result = await firstValueFrom(
+      this.groupService.getMyGroup({ userId }),
+    );
+    console.log('[getMyGroupIds] raw result:', JSON.stringify(result));
+    return new Set((result.groupId ?? []).map(Number));
+  }
 }

src/proto/group.proto

@@ -2,9 +2,21 @@ syntax = "proto3";
 
 package group.v1;
 
+
+option java_multiple_files = true;
+option java_package = "flipnote.group.grpc.v1";
+option java_outer_classname = "GroupServiceProto";
+
 service GroupCommandService {
-  rpc GetGroupName (GetGroupNameRequest) returns (GetGroupNameResponse);
-  rpc CheckUserInGroup (CheckUserInGroupRequest) returns (CheckUserInGroupResponse);
+
+  // 그룹 이름 조회
+  rpc GetGroupName(GetGroupNameRequest) returns (GetGroupNameResponse);
+
+  // 그룹 내 유저 존재 여부 확인
+  rpc CheckUserInGroup(CheckUserInGroupRequest) returns (CheckUserInGroupResponse);
+
+  // 내 그룹 전체 조회
+  rpc GetMyGroup(GetMyGroupRequest) returns (GetMyGroupResponse);
 }
 
 message GetGroupNameRequest {
@@ -23,3 +35,11 @@ message CheckUserInGroupRequest {
 message CheckUserInGroupResponse {
   bool exists = 1;
 }
+
+message GetMyGroupRequest {
+  int64 user_id = 1;
+}
+
+message GetMyGroupResponse {
+  repeated int64 group_id = 1;
+}