add redis cache to results

go.sum

@@ -138,13 +138,8 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-<<<<<<< HEAD
 github.com/redis/go-redis/v9 v9.16.0 h1:OotgqgLSRCmzfqChbQyG1PHC3tLNR89DG4jdOERSEP4=
 github.com/redis/go-redis/v9 v9.16.0/go.mod h1:u410H11HMLoB+TP67dz8rL9s6QW2j76l0//kSOd3370=
-=======
-github.com/redis/go-redis/v9 v9.17.2 h1:P2EGsA4qVIM3Pp+aPocCJ7DguDHhqrXNhVcEp4ViluI=
-github.com/redis/go-redis/v9 v9.17.2/go.mod h1:u410H11HMLoB+TP67dz8rL9s6QW2j76l0//kSOd3370=
->>>>>>> origin/feature/task
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

internal/results/config/config.go

@@ -20,9 +20,11 @@ type Config struct {
 	DBUser                string
 	DBPassword            string
 	DBName                string
+	RedisAddr             string
 	UserServiceAddr       string
 	SubmissionServiceAddr string
 	TaskServiceAddr       string
+	CacheEnabled          bool
 }
 
 func Load() (*Config, error) {
@@ -38,9 +40,11 @@ func Load() (*Config, error) {
 		DBUser:                getEnv("POSTGRES_USERNAME", "postgres"),
 		DBPassword:            getEnv("POSTGRES_PASSWORD", "postgres"),
 		DBName:                getEnv("POSTGRES_DATABASE", "postgres"),
+		RedisAddr:             getEnv("REDIS_ADDR", "localhost:6379"),
 		UserServiceAddr:       getEnv("USER_GRPC_ADDR", "localhost:50051"),
 		SubmissionServiceAddr: getEnv("SUBMISSION_GRPC_ADDR", "localhost:50055"),
 		TaskServiceAddr:       getEnv("TASK_GRPC_ADDR", "localhost:50056"),
+		CacheEnabled:          mustGetBool("CACHE_ENABLED", false),
 	}, nil
 }
 

internal/results/repository/postgres/result.go

@@ -17,8 +17,14 @@ import (
 
 const (
 	resultCachePrefix      = "result:"
+	leaderboardCachePrefix = "leaderboard:"
 )
 
+type leaderboardCache struct {
+	Results    []domain.Result `json:"results"`
+	TotalCount int             `json:"total_count"`
+}
+
 type ResultRepository struct {
 	db           *sql.DB
 	redisClient  *redis.Client
@@ -37,6 +43,21 @@ func (r *ResultRepository) cacheKey(id string) string {
 	return resultCachePrefix + id
 }
 
+func (r *ResultRepository) leaderboardCacheKey(competitionID uuid.UUID, limit, offset int) string {
+	return fmt.Sprintf("%s%s:limit:%d:offset:%d", leaderboardCachePrefix, competitionID.String(), limit, offset)
+}
+
+func (r *ResultRepository) invalidateLeaderboardCache(ctx context.Context, competitionID uuid.UUID) {
+	if !r.cacheEnabled {
+		return
+	}
+	pattern := fmt.Sprintf("%s%s:*", leaderboardCachePrefix, competitionID.String())
+	keys, err := r.redisClient.Keys(ctx, pattern).Result()
+	if err == nil && len(keys) > 0 {
+		r.redisClient.Del(ctx, keys...).Err()
+	}
+}
+
 func (r *ResultRepository) Create(ctx context.Context, result *domain.Result) error {
 	metadataJSON, err := json.Marshal(result.Metadata)
 	if err != nil {
@@ -65,6 +86,7 @@ func (r *ResultRepository) Create(ctx context.Context, result *domain.Result) er
 	}
 
 	if r.cacheEnabled {
+		r.invalidateLeaderboardCache(ctx, result.CompetitionID)
 		data, err := json.Marshal(result)
 		if err == nil {
 			r.redisClient.Set(ctx, r.cacheKey(result.ID.String()), data, 10*time.Minute).Err()
@@ -160,6 +182,7 @@ func (r *ResultRepository) Update(ctx context.Context, result *domain.Result) er
 	}
 
 	if r.cacheEnabled {
+		r.invalidateLeaderboardCache(ctx, result.CompetitionID)
 		r.redisClient.Del(ctx, r.cacheKey(result.ID.String())).Err()
 	}
 
@@ -312,6 +335,16 @@ func (r *ResultRepository) GetByCompetitionAndUser(ctx context.Context, competit
 }
 
 func (r *ResultRepository) GetLeaderboard(ctx context.Context, competitionID uuid.UUID, limit int, offset int) ([]domain.Result, int, error) {
+	if r.cacheEnabled {
+		key := r.leaderboardCacheKey(competitionID, limit, offset)
+		val, err := r.redisClient.Get(ctx, key).Result()
+		if err == nil {
+			var cached leaderboardCache
+			if json.Unmarshal([]byte(val), &cached) == nil {
+				return cached.Results, cached.TotalCount, nil
+			}
+		}
+	}
 	countQuery := `SELECT COUNT(*) FROM results WHERE competition_id = $1 AND status = $2`
 	var total int
 	if err := r.db.QueryRowContext(ctx, countQuery, competitionID, domain.ResultStatusCompleted).Scan(&total); err != nil {
@@ -359,6 +392,15 @@ func (r *ResultRepository) GetLeaderboard(ctx context.Context, competitionID uui
 		results = append(results, result)
 	}
 
+	if r.cacheEnabled {
+		key := r.leaderboardCacheKey(competitionID, limit, offset)
+		cacheData := leaderboardCache{Results: results, TotalCount: total}
+		data, err := json.Marshal(cacheData)
+		if err == nil {
+			r.redisClient.Set(ctx, key, data, 1*time.Minute).Err()
+		}
+	}
+
 	return results, total, nil
 }
 
@@ -382,7 +424,16 @@ func (r *ResultRepository) UpdateStatus(ctx context.Context, id uuid.UUID, statu
 		r.redisClient.Del(ctx, r.cacheKey(id.String())).Err()
 	}
 
-	return r.Get(ctx, id)
+	result, err := r.Get(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+
+	if r.cacheEnabled {
+		r.invalidateLeaderboardCache(ctx, result.CompetitionID)
+	}
+
+	return result, nil
 }
 
 func (r *ResultRepository) RecalculateRanks(ctx context.Context, competitionID uuid.UUID) error {
@@ -425,5 +476,14 @@ func (r *ResultRepository) RecalculateRanks(ctx context.Context, competitionID u
 		}
 	}
 
-	return tx.Commit()
+	err = tx.Commit()
+	if err != nil {
+		return err
+	}
+
+	if r.cacheEnabled {
+		r.invalidateLeaderboardCache(ctx, competitionID)
+	}
+
+	return nil
 }

internal/results/server/server.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/jmoiron/sqlx"
 	_ "github.com/lib/pq"
+	"github.com/redis/go-redis/v9"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/reflection"
 )
@@ -30,6 +31,7 @@ type Server struct {
 	httpServer *http.Server
 	config     *config.Config
 	db         *sqlx.DB
+	redis      *redis.Client
 }
 
 func New(cfg *config.Config) *Server {
@@ -45,6 +47,11 @@ func (s *Server) Start() error {
 	}
 	s.db = db
 
+	redisClient := redis.NewClient(&redis.Options{
+		Addr: s.config.RedisAddr,
+	})
+	s.redis = redisClient
+
 	go func() {
 		if err := s.startGRPCServer(); err != nil {
 			log.Fatalf("failed to start gRPC server: %v", err)
@@ -69,7 +76,7 @@ func (s *Server) startGRPCServer() error {
 }
 
 func (s *Server) registerGRPCServices() {
-	resultRepo := postgres.NewResultRepository(s.db.DB, nil, false)
+	resultRepo := postgres.NewResultRepository(s.db.DB, s.redis, s.config.CacheEnabled)
 	resultService := service.NewService(resultRepo)
 	resultHandler := grpcHandlers.NewResultsHandler(
 		resultService,
@@ -98,5 +105,11 @@ func (s *Server) Stop() {
 		}
 	}
 
+	if s.redis != nil {
+		if err := s.redis.Close(); err != nil {
+			log.Printf("failed to close redis connection: %v", err)
+		}
+	}
+
 	log.Println("results server stopped")
 }