fix: remove stale user settings cache

backend/internal/application/conversation/context_compaction_policy.go

@@ -20,7 +20,7 @@ func (s *Service) resolveContextCompactionPolicy(ctx context.Context, cfg config
 		AdminEnabled: cfg.ContextCompactEnabled,
 		UserEnabled:  true,
 	}
-	if val, valErr := s.getUserSettingCached(ctx, userID, "chat.context_compact_auto"); valErr == nil && val == "false" {
+	if val, valErr := s.repo.GetUserSettingValue(ctx, userID, "chat.context_compact_auto"); valErr == nil && val == "false" {
 		policy.UserEnabled = false
 	}
 	return policy

backend/internal/application/conversation/service.go

@@ -117,7 +117,6 @@ type Service struct {
 	generationStreams *generationStreamRegistry
 	snapshotCache     sync.Map // conversationID (uint) → *cachedSnapshot
 	userMemCache      sync.Map // userID (uint) → *cachedUserMemories
-	userSettingCache  sync.Map // "userID:key" (string) → *cachedUserSetting
 	imageContextCache *preparedConversationImageCache
 }
 

backend/internal/application/conversation/service_cache.go

@@ -2,7 +2,6 @@ package conversation
 
 import (
 	"context"
-	"fmt"
 	"time"
 
 	model "github.com/DEEIX-AI/DEEIX-Chat/backend/internal/domain/conversation"
@@ -14,8 +13,6 @@ const (
 	snapshotCacheTTL = 2 * time.Minute
 	// userMemCacheTTL：用户记忆在会话期间极少变化，缓存 3 分钟。
 	userMemCacheTTL = 3 * time.Minute
-	// userSettingCacheTTL：用户设置在会话期间几乎不变，缓存 10 分钟。
-	userSettingCacheTTL = 10 * time.Minute
 	// inMemoryCacheSweepInterval：主动清理过期内存缓存，避免冷 key 长期驻留。
 	inMemoryCacheSweepInterval = time.Minute
 )
@@ -30,12 +27,6 @@ type cachedUserMemories struct {
 	expiresAt time.Time
 }
 
-type cachedUserSetting struct {
-	value     string
-	valid     bool
-	expiresAt time.Time
-}
-
 // getCachedSnapshot 从内存缓存读取最新 Snapshot，未命中时回退到 DB 查询。
 func (s *Service) getCachedSnapshot(ctx context.Context, conversationID uint) (*model.ContextSnapshot, error) {
 	if v, ok := s.snapshotCache.Load(conversationID); ok {
@@ -61,28 +52,6 @@ func (s *Service) invalidateSnapshotCache(conversationID uint) {
 	s.snapshotCache.Delete(conversationID)
 }
 
-// getUserSettingCached 从内存缓存读取用户设置，未命中时回退到 DB 查询。
-func (s *Service) getUserSettingCached(ctx context.Context, userID uint, key string) (string, error) {
-	cacheKey := fmt.Sprintf("%d:%s", userID, key)
-	if v, ok := s.userSettingCache.Load(cacheKey); ok {
-		entry := v.(*cachedUserSetting)
-		if time.Now().Before(entry.expiresAt) {
-			if !entry.valid {
-				return "", fmt.Errorf("not found")
-			}
-			return entry.value, nil
-		}
-		s.userSettingCache.Delete(cacheKey)
-	}
-	val, err := s.repo.GetUserSettingValue(ctx, userID, key)
-	if err != nil {
-		s.userSettingCache.Store(cacheKey, &cachedUserSetting{valid: false, expiresAt: time.Now().Add(userSettingCacheTTL)})
-		return "", err
-	}
-	s.userSettingCache.Store(cacheKey, &cachedUserSetting{value: val, valid: true, expiresAt: time.Now().Add(userSettingCacheTTL)})
-	return val, nil
-}
-
 // getCachedUserMemories 从内存缓存读取用户长期记忆，未命中时回退到 DB 查询。
 func (s *Service) getCachedUserMemories(ctx context.Context, userID uint) ([]domainmemory.UserMemory, error) {
 	if v, ok := s.userMemCache.Load(userID); ok {
@@ -136,11 +105,4 @@ func (s *Service) cleanupExpiredInMemoryCaches(now time.Time) {
 		}
 		return true
 	})
-	s.userSettingCache.Range(func(key, value interface{}) bool {
-		entry, ok := value.(*cachedUserSetting)
-		if !ok || !now.Before(entry.expiresAt) {
-			s.userSettingCache.Delete(key)
-		}
-		return true
-	})
 }

backend/internal/application/conversation/service_cache_test.go

@@ -13,8 +13,6 @@ func TestCleanupExpiredInMemoryCaches(t *testing.T) {
 	svc.snapshotCache.Store(uint(2), &cachedSnapshot{expiresAt: now.Add(time.Minute)})
 	svc.userMemCache.Store(uint(1), &cachedUserMemories{expiresAt: now.Add(-time.Second)})
 	svc.userMemCache.Store(uint(2), &cachedUserMemories{expiresAt: now.Add(time.Minute)})
-	svc.userSettingCache.Store("1:stale", &cachedUserSetting{expiresAt: now.Add(-time.Second)})
-	svc.userSettingCache.Store("1:fresh", &cachedUserSetting{expiresAt: now.Add(time.Minute)})
 
 	svc.cleanupExpiredInMemoryCaches(now)
 
@@ -30,10 +28,4 @@ func TestCleanupExpiredInMemoryCaches(t *testing.T) {
 	if _, ok := svc.userMemCache.Load(uint(2)); !ok {
 		t.Fatal("expected fresh user memory cache entry to remain")
 	}
-	if _, ok := svc.userSettingCache.Load("1:stale"); ok {
-		t.Fatal("expected expired user setting cache entry to be deleted")
-	}
-	if _, ok := svc.userSettingCache.Load("1:fresh"); !ok {
-		t.Fatal("expected fresh user setting cache entry to remain")
-	}
 }

backend/internal/application/conversation/service_message_send.go

@@ -48,10 +48,18 @@ func (s *Service) reasoningContentPassbackEnabled(ctx context.Context, userID ui
 	if route == nil || !route.ReasoningContentPassback {
 		return false
 	}
-	value, err := s.getUserSettingCached(ctx, userID, reasoningContentPassbackSettingKey)
+	value, err := s.repo.GetUserSettingValue(ctx, userID, reasoningContentPassbackSettingKey)
 	return err == nil && value != "false"
 }
 
+func (s *Service) resolveMessageFileMode(ctx context.Context, userID uint) string {
+	fileMode := "auto"
+	if fm, fmErr := s.repo.GetUserSettingValue(ctx, userID, "chat.file_mode"); fmErr == nil && fm != "" {
+		fileMode = fm
+	}
+	return fileMode
+}
+
 func messageRouteConfig(route *channel.ResolvedRoute, attributionReferer string, attributionTitle string) llm.RouteConfig {
 	return llm.RouteConfig{
 		Protocol:            route.Protocol,
@@ -398,11 +406,8 @@ func (s *Service) sendMessageInternal(
 	}()
 
 	// 读取用户的文件处理模式偏好（auto / full_context / rag）。
-	fileMode := "auto"
 	capability := s.resolveChatFileCapability(ctx)
-	if fm, fmErr := s.getUserSettingCached(ctx, input.UserID, "chat.file_mode"); fmErr == nil && fm != "" {
-		fileMode = fm
-	}
+	fileMode := s.resolveMessageFileMode(ctx, input.UserID)
 
 	// 收集并行预取结果，再规划本轮可发送的 PromptScope。
 	prefetch := <-prefetchCh

backend/internal/application/conversation/service_user_settings_test.go

@@ -0,0 +1,90 @@
+package conversation
+
+import (
+	"context"
+	"testing"
+
+	"github.com/DEEIX-AI/DEEIX-Chat/backend/internal/application/channel"
+	appusersettings "github.com/DEEIX-AI/DEEIX-Chat/backend/internal/application/usersettings"
+	domainusersettings "github.com/DEEIX-AI/DEEIX-Chat/backend/internal/domain/usersettings"
+	"github.com/DEEIX-AI/DEEIX-Chat/backend/internal/infra/config"
+	"github.com/DEEIX-AI/DEEIX-Chat/backend/internal/repository"
+)
+
+type mutableUserSettingsRepository struct {
+	repository.ConversationRepository
+	values map[uint]map[string]string
+}
+
+func (r *mutableUserSettingsRepository) GetUserSettingValue(_ context.Context, userID uint, key string) (string, error) {
+	return r.values[userID][key], nil
+}
+
+func (r *mutableUserSettingsRepository) ListByUserID(_ context.Context, userID uint) ([]domainusersettings.UserSetting, error) {
+	values := r.values[userID]
+	items := make([]domainusersettings.UserSetting, 0, len(values))
+	for key, value := range values {
+		items = append(items, domainusersettings.UserSetting{UserID: userID, Key: key, Value: value})
+	}
+	return items, nil
+}
+
+func (r *mutableUserSettingsRepository) Upsert(_ context.Context, items []domainusersettings.UserSetting) error {
+	for _, item := range items {
+		if r.values[item.UserID] == nil {
+			r.values[item.UserID] = make(map[string]string)
+		}
+		r.values[item.UserID][item.Key] = item.Value
+	}
+	return nil
+}
+
+func TestConversationSettingsReadPatchedValuesImmediately(t *testing.T) {
+	const userID uint = 17
+	ctx := context.Background()
+	runtimeCfg := config.NewRuntime(config.Config{ContextCompactEnabled: true})
+	repo := &mutableUserSettingsRepository{
+		values: map[uint]map[string]string{
+			userID: {
+				"chat.reasoning_content_passback": "true",
+				"chat.context_compact_auto":       "true",
+				"chat.file_mode":                  "auto",
+			},
+		},
+	}
+	conversationService := &Service{
+		cfg:  runtimeCfg,
+		repo: repo,
+	}
+	settingsService := appusersettings.NewService(repo)
+
+	if !conversationService.reasoningContentPassbackEnabled(ctx, userID, &channel.ResolvedRoute{ReasoningContentPassback: true}) {
+		t.Fatal("expected initial reasoning passback to be enabled")
+	}
+	if !conversationService.resolveContextCompactionPolicy(ctx, runtimeCfg.Snapshot(), userID).EffectiveEnabled() {
+		t.Fatal("expected initial context compaction to be enabled")
+	}
+	initialFileMode := conversationService.resolveMessageFileMode(ctx, userID)
+	if initialFileMode != "auto" {
+		t.Fatalf("initial message file mode = %q, want auto", initialFileMode)
+	}
+
+	if _, err := settingsService.PatchSettings(ctx, userID, map[string]string{
+		"chat.reasoning_content_passback": "false",
+		"chat.context_compact_auto":       "false",
+		"chat.file_mode":                  "rag",
+	}); err != nil {
+		t.Fatalf("patch settings: %v", err)
+	}
+
+	if conversationService.reasoningContentPassbackEnabled(ctx, userID, &channel.ResolvedRoute{ReasoningContentPassback: true}) {
+		t.Fatal("expected patched reasoning passback to be disabled")
+	}
+	if conversationService.resolveContextCompactionPolicy(ctx, runtimeCfg.Snapshot(), userID).EffectiveEnabled() {
+		t.Fatal("expected patched context compaction to be disabled")
+	}
+	updatedFileMode := conversationService.resolveMessageFileMode(ctx, userID)
+	if updatedFileMode != "rag" {
+		t.Fatalf("updated message file mode = %q, want rag", updatedFileMode)
+	}
+}