feat: DB DI 전환 + download 하위 호환성 + race condition 수정

- middleware(Auth, Idempotency)를 클로저 팩토리 패턴으로 DI 전환
- database.DB/RDB 전역 변수 제거, ConnectMySQL/Redis 값 반환으로 변경
- download API X-API-Version 헤더 + 하위 호환성 규칙 문서화
- SaveGameData PlayTimeDelta 원자적 UPDATE (race condition 해소)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-03-18 16:58:36 +09:00
parent f4d862b47f
commit 0dfa744c16
9 changed files with 226 additions and 199 deletions

View File

@@ -8,8 +8,8 @@ import (
"time"
"a301_server/pkg/apperror"
"a301_server/pkg/database"
"github.com/gofiber/fiber/v2"
"github.com/redis/go-redis/v9"
)
const idempotencyTTL = 10 * time.Minute
@@ -20,95 +20,100 @@ type cachedResponse struct {
Body json.RawMessage `json:"b"`
}
// IdempotencyRequired rejects requests without an Idempotency-Key header,
// then delegates to Idempotency for cache/replay logic.
func IdempotencyRequired(c *fiber.Ctx) error {
if c.Get("Idempotency-Key") == "" {
return apperror.BadRequest("Idempotency-Key 헤더가 필요합니다")
// IdempotencyRequired returns a middleware that rejects requests without an Idempotency-Key header,
// then delegates to idempotency cache/replay logic.
func IdempotencyRequired(rdb *redis.Client) fiber.Handler {
idempotency := Idempotency(rdb)
return func(c *fiber.Ctx) error {
if c.Get("Idempotency-Key") == "" {
return apperror.BadRequest("Idempotency-Key 헤더가 필요합니다")
}
return idempotency(c)
}
return Idempotency(c)
}
// Idempotency checks the Idempotency-Key header to prevent duplicate transactions.
// Idempotency returns a middleware that checks the Idempotency-Key header to prevent duplicate transactions.
// If the same key is seen again within the TTL, the cached response is returned.
func Idempotency(c *fiber.Ctx) error {
key := c.Get("Idempotency-Key")
if key == "" {
return c.Next()
}
if len(key) > 256 {
return apperror.BadRequest("Idempotency-Key가 너무 깁니다")
}
func Idempotency(rdb *redis.Client) fiber.Handler {
return func(c *fiber.Ctx) error {
key := c.Get("Idempotency-Key")
if key == "" {
return c.Next()
}
if len(key) > 256 {
return apperror.BadRequest("Idempotency-Key가 너무 깁니다")
}
// userID가 있으면 키에 포함하여 사용자 간 캐시 충돌 방지
redisKey := "idempotency:"
if uid, ok := c.Locals("userID").(uint); ok {
redisKey += fmt.Sprintf("u%d:", uid)
}
redisKey += key
// userID가 있으면 키에 포함하여 사용자 간 캐시 충돌 방지
redisKey := "idempotency:"
if uid, ok := c.Locals("userID").(uint); ok {
redisKey += fmt.Sprintf("u%d:", uid)
}
redisKey += key
ctx, cancel := context.WithTimeout(context.Background(), redisTimeout)
defer cancel()
ctx, cancel := context.WithTimeout(context.Background(), redisTimeout)
defer cancel()
// Atomically claim the key using SET NX (only succeeds if key doesn't exist)
set, err := database.RDB.SetNX(ctx, redisKey, "processing", idempotencyTTL).Result()
if err != nil {
// Redis error — let the request through rather than blocking
log.Printf("WARNING: idempotency SetNX failed (key=%s): %v", key, err)
return c.Next()
}
if !set {
// Key already exists — either processing or completed
getCtx, getCancel := context.WithTimeout(context.Background(), redisTimeout)
defer getCancel()
cached, err := database.RDB.Get(getCtx, redisKey).Bytes()
// Atomically claim the key using SET NX (only succeeds if key doesn't exist)
set, err := rdb.SetNX(ctx, redisKey, "processing", idempotencyTTL).Result()
if err != nil {
// Redis error — let the request through rather than blocking
log.Printf("WARNING: idempotency SetNX failed (key=%s): %v", key, err)
return c.Next()
}
if !set {
// Key already exists — either processing or completed
getCtx, getCancel := context.WithTimeout(context.Background(), redisTimeout)
defer getCancel()
cached, err := rdb.Get(getCtx, redisKey).Bytes()
if err != nil {
return apperror.Conflict("요청이 처리 중입니다")
}
if string(cached) == "processing" {
return apperror.Conflict("요청이 처리 중입니다")
}
var cr cachedResponse
if json.Unmarshal(cached, &cr) == nil {
c.Set("Content-Type", "application/json")
c.Set("X-Idempotent-Replay", "true")
return c.Status(cr.StatusCode).Send(cr.Body)
}
return apperror.Conflict("요청이 처리 중입니다")
}
if string(cached) == "processing" {
return apperror.Conflict("요청이 처리 중입니다")
}
var cr cachedResponse
if json.Unmarshal(cached, &cr) == nil {
c.Set("Content-Type", "application/json")
c.Set("X-Idempotent-Replay", "true")
return c.Status(cr.StatusCode).Send(cr.Body)
}
return apperror.Conflict("요청이 처리 중입니다")
}
// We claimed the key — process the request
if err := c.Next(); err != nil {
// Processing failed — remove the key so it can be retried
delCtx, delCancel := context.WithTimeout(context.Background(), redisTimeout)
defer delCancel()
if delErr := database.RDB.Del(delCtx, redisKey).Err(); delErr != nil {
log.Printf("WARNING: idempotency cache delete failed (key=%s): %v", key, delErr)
// We claimed the key — process the request
if err := c.Next(); err != nil {
// Processing failed — remove the key so it can be retried
delCtx, delCancel := context.WithTimeout(context.Background(), redisTimeout)
defer delCancel()
if delErr := rdb.Del(delCtx, redisKey).Err(); delErr != nil {
log.Printf("WARNING: idempotency cache delete failed (key=%s): %v", key, delErr)
}
return err
}
return err
}
// Cache successful responses (2xx), otherwise remove the key for retry
status := c.Response().StatusCode()
if status >= 200 && status < 300 {
cr := cachedResponse{StatusCode: status, Body: c.Response().Body()}
if data, err := json.Marshal(cr); err == nil {
writeCtx, writeCancel := context.WithTimeout(context.Background(), redisTimeout)
defer writeCancel()
if err := database.RDB.Set(writeCtx, redisKey, data, idempotencyTTL).Err(); err != nil {
log.Printf("WARNING: idempotency cache write failed (key=%s): %v", key, err)
// Cache successful responses (2xx), otherwise remove the key for retry
status := c.Response().StatusCode()
if status >= 200 && status < 300 {
cr := cachedResponse{StatusCode: status, Body: c.Response().Body()}
if data, err := json.Marshal(cr); err == nil {
writeCtx, writeCancel := context.WithTimeout(context.Background(), redisTimeout)
defer writeCancel()
if err := rdb.Set(writeCtx, redisKey, data, idempotencyTTL).Err(); err != nil {
log.Printf("WARNING: idempotency cache write failed (key=%s): %v", key, err)
}
}
} else {
// Non-success — allow retry by removing the key
delCtx, delCancel := context.WithTimeout(context.Background(), redisTimeout)
defer delCancel()
if delErr := rdb.Del(delCtx, redisKey).Err(); delErr != nil {
log.Printf("WARNING: idempotency cache delete failed (key=%s): %v", key, delErr)
}
}
} else {
// Non-success — allow retry by removing the key
delCtx, delCancel := context.WithTimeout(context.Background(), redisTimeout)
defer delCancel()
if delErr := database.RDB.Del(delCtx, redisKey).Err(); delErr != nil {
log.Printf("WARNING: idempotency cache delete failed (key=%s): %v", key, delErr)
}
}
return nil
return nil
}
}