Merge pull request #931 from xvhuan/fix/db-write-amplification-20260311

降低 quota 与 Codex 快照热路径的数据库写放大

backend/internal/service/account_usage_service.go

@@ -369,8 +369,11 @@ func (s *AccountUsageService) getOpenAIUsage(ctx context.Context, account *Accou
 	}
 
 	if shouldRefreshOpenAICodexSnapshot(account, usage, now) && s.shouldProbeOpenAICodexSnapshot(account.ID, now) {
-		if updates, err := s.probeOpenAICodexSnapshot(ctx, account); err == nil && len(updates) > 0 {
+		if updates, resetAt, err := s.probeOpenAICodexSnapshot(ctx, account); err == nil && (len(updates) > 0 || resetAt != nil) {
 			mergeAccountExtra(account, updates)
+			if resetAt != nil {
+				account.RateLimitResetAt = resetAt
+			}
 			if usage.UpdatedAt == nil {
 				usage.UpdatedAt = &now
 			}
@@ -457,26 +460,26 @@ func (s *AccountUsageService) shouldProbeOpenAICodexSnapshot(accountID int64, no
 	return true
 }
 
-func (s *AccountUsageService) probeOpenAICodexSnapshot(ctx context.Context, account *Account) (map[string]any, error) {
+func (s *AccountUsageService) probeOpenAICodexSnapshot(ctx context.Context, account *Account) (map[string]any, *time.Time, error) {
 	if account == nil || !account.IsOAuth() {
-		return nil, nil
+		return nil, nil, nil
 	}
 	accessToken := account.GetOpenAIAccessToken()
 	if accessToken == "" {
-		return nil, fmt.Errorf("no access token available")
+		return nil, nil, fmt.Errorf("no access token available")
 	}
 	modelID := openaipkg.DefaultTestModel
 	payload := createOpenAITestPayload(modelID, true)
 	payloadBytes, err := json.Marshal(payload)
 	if err != nil {
-		return nil, fmt.Errorf("marshal openai probe payload: %w", err)
+		return nil, nil, fmt.Errorf("marshal openai probe payload: %w", err)
 	}
 
 	reqCtx, cancel := context.WithTimeout(ctx, 15*time.Second)
 	defer cancel()
 	req, err := http.NewRequestWithContext(reqCtx, http.MethodPost, chatgptCodexURL, bytes.NewReader(payloadBytes))
 	if err != nil {
-		return nil, fmt.Errorf("create openai probe request: %w", err)
+		return nil, nil, fmt.Errorf("create openai probe request: %w", err)
 	}
 	req.Host = "chatgpt.com"
 	req.Header.Set("Content-Type", "application/json")
@@ -505,43 +508,67 @@ func (s *AccountUsageService) probeOpenAICodexSnapshot(ctx context.Context, acco
 		ResponseHeaderTimeout: 10 * time.Second,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("build openai probe client: %w", err)
+		return nil, nil, fmt.Errorf("build openai probe client: %w", err)
 	}
 	resp, err := client.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("openai codex probe request failed: %w", err)
+		return nil, nil, fmt.Errorf("openai codex probe request failed: %w", err)
 	}
 	defer func() { _ = resp.Body.Close() }()
 
-	updates, err := extractOpenAICodexProbeUpdates(resp)
+	updates, resetAt, err := extractOpenAICodexProbeSnapshot(resp)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	if len(updates) > 0 {
-		go func(accountID int64, updates map[string]any) {
-			updateCtx, updateCancel := context.WithTimeout(context.Background(), 5*time.Second)
-			defer updateCancel()
+	if len(updates) > 0 || resetAt != nil {
+		s.persistOpenAICodexProbeSnapshot(account.ID, updates, resetAt)
+		return updates, resetAt, nil
+	}
+	return nil, nil, nil
+}
+
+func (s *AccountUsageService) persistOpenAICodexProbeSnapshot(accountID int64, updates map[string]any, resetAt *time.Time) {
+	if s == nil || s.accountRepo == nil || accountID <= 0 {
+		return
+	}
+	if len(updates) == 0 && resetAt == nil {
+		return
+	}
+
+	go func() {
+		updateCtx, updateCancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer updateCancel()
+		if len(updates) > 0 {
 			_ = s.accountRepo.UpdateExtra(updateCtx, accountID, updates)
-		}(account.ID, updates)
-		return updates, nil
+		}
+		if resetAt != nil {
+			_ = s.accountRepo.SetRateLimited(updateCtx, accountID, *resetAt)
+		}
+	}()
+}
+
+func extractOpenAICodexProbeSnapshot(resp *http.Response) (map[string]any, *time.Time, error) {
+	if resp == nil {
+		return nil, nil, nil
 	}
-	return nil, nil
+	if snapshot := ParseCodexRateLimitHeaders(resp.Header); snapshot != nil {
+		baseTime := time.Now()
+		updates := buildCodexUsageExtraUpdates(snapshot, baseTime)
+		resetAt := codexRateLimitResetAtFromSnapshot(snapshot, baseTime)
+		if len(updates) > 0 {
+			return updates, resetAt, nil
+		}
+		return nil, resetAt, nil
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, nil, fmt.Errorf("openai codex probe returned status %d", resp.StatusCode)
+	}
+	return nil, nil, nil
 }
 
 func extractOpenAICodexProbeUpdates(resp *http.Response) (map[string]any, error) {
-	if resp == nil {
-		return nil, nil
-	}
-	if snapshot := ParseCodexRateLimitHeaders(resp.Header); snapshot != nil {
-		updates := buildCodexUsageExtraUpdates(snapshot, time.Now())
-		if len(updates) > 0 {
-			return updates, nil
-		}
-	}
-	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return nil, fmt.Errorf("openai codex probe returned status %d", resp.StatusCode)
-	}
-	return nil, nil
+	updates, _, err := extractOpenAICodexProbeSnapshot(resp)
+	return updates, err
 }
 
 func mergeAccountExtra(account *Account, updates map[string]any) {

backend/internal/service/account_usage_service_test.go

@@ -1,11 +1,36 @@
 package service
 
 import (
+	"context"
 	"net/http"
 	"testing"
 	"time"
 )
 
+type accountUsageCodexProbeRepo struct {
+	stubOpenAIAccountRepo
+	updateExtraCh chan map[string]any
+	rateLimitCh   chan time.Time
+}
+
+func (r *accountUsageCodexProbeRepo) UpdateExtra(_ context.Context, _ int64, updates map[string]any) error {
+	if r.updateExtraCh != nil {
+		copied := make(map[string]any, len(updates))
+		for k, v := range updates {
+			copied[k] = v
+		}
+		r.updateExtraCh <- copied
+	}
+	return nil
+}
+
+func (r *accountUsageCodexProbeRepo) SetRateLimited(_ context.Context, _ int64, resetAt time.Time) error {
+	if r.rateLimitCh != nil {
+		r.rateLimitCh <- resetAt
+	}
+	return nil
+}
+
 func TestShouldRefreshOpenAICodexSnapshot(t *testing.T) {
 	t.Parallel()
 
@@ -66,3 +91,60 @@ func TestExtractOpenAICodexProbeUpdatesAccepts429WithCodexHeaders(t *testing.T)
 		t.Fatalf("codex_7d_used_percent = %v, want 100", got)
 	}
 }
+
+func TestExtractOpenAICodexProbeSnapshotAccepts429WithResetAt(t *testing.T) {
+	t.Parallel()
+
+	headers := make(http.Header)
+	headers.Set("x-codex-primary-used-percent", "100")
+	headers.Set("x-codex-primary-reset-after-seconds", "604800")
+	headers.Set("x-codex-primary-window-minutes", "10080")
+	headers.Set("x-codex-secondary-used-percent", "100")
+	headers.Set("x-codex-secondary-reset-after-seconds", "18000")
+	headers.Set("x-codex-secondary-window-minutes", "300")
+
+	updates, resetAt, err := extractOpenAICodexProbeSnapshot(&http.Response{StatusCode: http.StatusTooManyRequests, Header: headers})
+	if err != nil {
+		t.Fatalf("extractOpenAICodexProbeSnapshot() error = %v", err)
+	}
+	if len(updates) == 0 {
+		t.Fatal("expected codex probe updates from 429 headers")
+	}
+	if resetAt == nil {
+		t.Fatal("expected resetAt from exhausted codex headers")
+	}
+}
+
+func TestAccountUsageService_PersistOpenAICodexProbeSnapshotSetsRateLimit(t *testing.T) {
+	t.Parallel()
+
+	repo := &accountUsageCodexProbeRepo{
+		updateExtraCh: make(chan map[string]any, 1),
+		rateLimitCh:   make(chan time.Time, 1),
+	}
+	svc := &AccountUsageService{accountRepo: repo}
+	resetAt := time.Now().Add(2 * time.Hour).UTC().Truncate(time.Second)
+
+	svc.persistOpenAICodexProbeSnapshot(321, map[string]any{
+		"codex_7d_used_percent": 100.0,
+		"codex_7d_reset_at":     resetAt.Format(time.RFC3339),
+	}, &resetAt)
+
+	select {
+	case updates := <-repo.updateExtraCh:
+		if got := updates["codex_7d_used_percent"]; got != 100.0 {
+			t.Fatalf("codex_7d_used_percent = %v, want 100", got)
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("waiting for codex probe extra persistence timed out")
+	}
+
+	select {
+	case got := <-repo.rateLimitCh:
+		if got.Before(resetAt.Add(-time.Second)) || got.After(resetAt.Add(time.Second)) {
+			t.Fatalf("rate limit resetAt = %v, want around %v", got, resetAt)
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("waiting for codex probe rate limit persistence timed out")
+	}
+}

backend/internal/service/api_key_service.go

@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -110,6 +111,15 @@ func (d *APIKeyRateLimitData) EffectiveUsage7d() float64 {
 	return d.Usage7d
 }
 
+// APIKeyQuotaUsageState captures the latest quota fields after an atomic quota update.
+// It is intentionally small so repositories can return it from a single SQL statement.
+type APIKeyQuotaUsageState struct {
+	QuotaUsed float64
+	Quota     float64
+	Key       string
+	Status    string
+}
+
 // APIKeyCache defines cache operations for API key service
 type APIKeyCache interface {
 	GetCreateAttemptCount(ctx context.Context, userID int64) (int, error)
@@ -817,6 +827,21 @@ func (s *APIKeyService) UpdateQuotaUsed(ctx context.Context, apiKeyID int64, cos
 		return nil
 	}
 
+	type quotaStateReader interface {
+		IncrementQuotaUsedAndGetState(ctx context.Context, id int64, amount float64) (*APIKeyQuotaUsageState, error)
+	}
+
+	if repo, ok := s.apiKeyRepo.(quotaStateReader); ok {
+		state, err := repo.IncrementQuotaUsedAndGetState(ctx, apiKeyID, cost)
+		if err != nil {
+			return fmt.Errorf("increment quota used: %w", err)
+		}
+		if state != nil && state.Status == StatusAPIKeyQuotaExhausted && strings.TrimSpace(state.Key) != "" {
+			s.InvalidateAuthCacheByKey(ctx, state.Key)
+		}
+		return nil
+	}
+
 	// Use repository to atomically increment quota_used
 	newQuotaUsed, err := s.apiKeyRepo.IncrementQuotaUsed(ctx, apiKeyID, cost)
 	if err != nil {

backend/internal/service/api_key_service_quota_test.go

@@ -0,0 +1,170 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
+	"github.com/stretchr/testify/require"
+)
+
+type quotaStateRepoStub struct {
+	quotaBaseAPIKeyRepoStub
+	stateCalls int
+	state      *APIKeyQuotaUsageState
+	stateErr   error
+}
+
+func (s *quotaStateRepoStub) IncrementQuotaUsedAndGetState(ctx context.Context, id int64, amount float64) (*APIKeyQuotaUsageState, error) {
+	s.stateCalls++
+	if s.stateErr != nil {
+		return nil, s.stateErr
+	}
+	if s.state == nil {
+		return nil, nil
+	}
+	out := *s.state
+	return &out, nil
+}
+
+type quotaStateCacheStub struct {
+	deleteAuthKeys []string
+}
+
+func (s *quotaStateCacheStub) GetCreateAttemptCount(context.Context, int64) (int, error) {
+	return 0, nil
+}
+
+func (s *quotaStateCacheStub) IncrementCreateAttemptCount(context.Context, int64) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) DeleteCreateAttemptCount(context.Context, int64) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) IncrementDailyUsage(context.Context, string) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) SetDailyUsageExpiry(context.Context, string, time.Duration) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) GetAuthCache(context.Context, string) (*APIKeyAuthCacheEntry, error) {
+	return nil, nil
+}
+
+func (s *quotaStateCacheStub) SetAuthCache(context.Context, string, *APIKeyAuthCacheEntry, time.Duration) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) DeleteAuthCache(_ context.Context, key string) error {
+	s.deleteAuthKeys = append(s.deleteAuthKeys, key)
+	return nil
+}
+
+func (s *quotaStateCacheStub) PublishAuthCacheInvalidation(context.Context, string) error {
+	return nil
+}
+
+func (s *quotaStateCacheStub) SubscribeAuthCacheInvalidation(context.Context, func(string)) error {
+	return nil
+}
+
+type quotaBaseAPIKeyRepoStub struct {
+	getByIDCalls int
+}
+
+func (s *quotaBaseAPIKeyRepoStub) Create(context.Context, *APIKey) error {
+	panic("unexpected Create call")
+}
+func (s *quotaBaseAPIKeyRepoStub) GetByID(context.Context, int64) (*APIKey, error) {
+	s.getByIDCalls++
+	return nil, nil
+}
+func (s *quotaBaseAPIKeyRepoStub) GetKeyAndOwnerID(context.Context, int64) (string, int64, error) {
+	panic("unexpected GetKeyAndOwnerID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) GetByKey(context.Context, string) (*APIKey, error) {
+	panic("unexpected GetByKey call")
+}
+func (s *quotaBaseAPIKeyRepoStub) GetByKeyForAuth(context.Context, string) (*APIKey, error) {
+	panic("unexpected GetByKeyForAuth call")
+}
+func (s *quotaBaseAPIKeyRepoStub) Update(context.Context, *APIKey) error {
+	panic("unexpected Update call")
+}
+func (s *quotaBaseAPIKeyRepoStub) Delete(context.Context, int64) error {
+	panic("unexpected Delete call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ListByUserID(context.Context, int64, pagination.PaginationParams, APIKeyListFilters) ([]APIKey, *pagination.PaginationResult, error) {
+	panic("unexpected ListByUserID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) VerifyOwnership(context.Context, int64, []int64) ([]int64, error) {
+	panic("unexpected VerifyOwnership call")
+}
+func (s *quotaBaseAPIKeyRepoStub) CountByUserID(context.Context, int64) (int64, error) {
+	panic("unexpected CountByUserID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ExistsByKey(context.Context, string) (bool, error) {
+	panic("unexpected ExistsByKey call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ListByGroupID(context.Context, int64, pagination.PaginationParams) ([]APIKey, *pagination.PaginationResult, error) {
+	panic("unexpected ListByGroupID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) SearchAPIKeys(context.Context, int64, string, int) ([]APIKey, error) {
+	panic("unexpected SearchAPIKeys call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ClearGroupIDByGroupID(context.Context, int64) (int64, error) {
+	panic("unexpected ClearGroupIDByGroupID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) CountByGroupID(context.Context, int64) (int64, error) {
+	panic("unexpected CountByGroupID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ListKeysByUserID(context.Context, int64) ([]string, error) {
+	panic("unexpected ListKeysByUserID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ListKeysByGroupID(context.Context, int64) ([]string, error) {
+	panic("unexpected ListKeysByGroupID call")
+}
+func (s *quotaBaseAPIKeyRepoStub) IncrementQuotaUsed(context.Context, int64, float64) (float64, error) {
+	panic("unexpected IncrementQuotaUsed call")
+}
+func (s *quotaBaseAPIKeyRepoStub) UpdateLastUsed(context.Context, int64, time.Time) error {
+	panic("unexpected UpdateLastUsed call")
+}
+func (s *quotaBaseAPIKeyRepoStub) IncrementRateLimitUsage(context.Context, int64, float64) error {
+	panic("unexpected IncrementRateLimitUsage call")
+}
+func (s *quotaBaseAPIKeyRepoStub) ResetRateLimitWindows(context.Context, int64) error {
+	panic("unexpected ResetRateLimitWindows call")
+}
+func (s *quotaBaseAPIKeyRepoStub) GetRateLimitData(context.Context, int64) (*APIKeyRateLimitData, error) {
+	panic("unexpected GetRateLimitData call")
+}
+
+func TestAPIKeyService_UpdateQuotaUsed_UsesAtomicStatePath(t *testing.T) {
+	repo := &quotaStateRepoStub{
+		state: &APIKeyQuotaUsageState{
+			QuotaUsed: 12,
+			Quota:     10,
+			Key:       "sk-test-quota",
+			Status:    StatusAPIKeyQuotaExhausted,
+		},
+	}
+	cache := &quotaStateCacheStub{}
+	svc := &APIKeyService{
+		apiKeyRepo: repo,
+		cache:      cache,
+	}
+
+	err := svc.UpdateQuotaUsed(context.Background(), 101, 2)
+	require.NoError(t, err)
+	require.Equal(t, 1, repo.stateCalls)
+	require.Equal(t, 0, repo.getByIDCalls, "fast path should not re-read API key by id")
+	require.Equal(t, []string{svc.authCacheKey("sk-test-quota")}, cache.deleteAuthKeys)
+}

backend/internal/service/openai_gateway_service.go

@@ -52,6 +52,8 @@ const (
 	openAIWSRetryJitterRatioDefault    = 0.2
 	openAICompactSessionSeedKey        = "openai_compact_session_seed"
 	codexCLIVersion                    = "0.104.0"
+	// Codex 限额快照仅用于后台展示/诊断，不需要每个成功请求都立即落库。
+	openAICodexSnapshotPersistMinInterval = 30 * time.Second
 )
 
 // OpenAI allowed headers whitelist (for non-passthrough).
@@ -255,6 +257,46 @@ type openAIWSRetryMetrics struct {
 	nonRetryableFastFallback atomic.Int64
 }
 
+type accountWriteThrottle struct {
+	minInterval time.Duration
+	mu          sync.Mutex
+	lastByID    map[int64]time.Time
+}
+
+func newAccountWriteThrottle(minInterval time.Duration) *accountWriteThrottle {
+	return &accountWriteThrottle{
+		minInterval: minInterval,
+		lastByID:    make(map[int64]time.Time),
+	}
+}
+
+func (t *accountWriteThrottle) Allow(id int64, now time.Time) bool {
+	if t == nil || id <= 0 || t.minInterval <= 0 {
+		return true
+	}
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if last, ok := t.lastByID[id]; ok && now.Sub(last) < t.minInterval {
+		return false
+	}
+	t.lastByID[id] = now
+
+	if len(t.lastByID) > 4096 {
+		cutoff := now.Add(-4 * t.minInterval)
+		for accountID, writtenAt := range t.lastByID {
+			if writtenAt.Before(cutoff) {
+				delete(t.lastByID, accountID)
+			}
+		}
+	}
+
+	return true
+}
+
+var defaultOpenAICodexSnapshotPersistThrottle = newAccountWriteThrottle(openAICodexSnapshotPersistMinInterval)
+
 // OpenAIGatewayService handles OpenAI API gateway operations
 type OpenAIGatewayService struct {
 	accountRepo           AccountRepository
@@ -289,6 +331,7 @@ type OpenAIGatewayService struct {
 	openaiWSFallbackUntil sync.Map // key: int64(accountID), value: time.Time
 	openaiWSRetryMetrics  openAIWSRetryMetrics
 	responseHeaderFilter  *responseheaders.CompiledHeaderFilter
+	codexSnapshotThrottle *accountWriteThrottle
 }
 
 // NewOpenAIGatewayService creates a new OpenAIGatewayService
@@ -329,17 +372,25 @@ func NewOpenAIGatewayService(
 			nil,
 			"service.openai_gateway",
 		),
-		httpUpstream:         httpUpstream,
-		deferredService:      deferredService,
-		openAITokenProvider:  openAITokenProvider,
-		toolCorrector:        NewCodexToolCorrector(),
-		openaiWSResolver:     NewOpenAIWSProtocolResolver(cfg),
-		responseHeaderFilter: compileResponseHeaderFilter(cfg),
+		httpUpstream:          httpUpstream,
+		deferredService:       deferredService,
+		openAITokenProvider:   openAITokenProvider,
+		toolCorrector:         NewCodexToolCorrector(),
+		openaiWSResolver:      NewOpenAIWSProtocolResolver(cfg),
+		responseHeaderFilter:  compileResponseHeaderFilter(cfg),
+		codexSnapshotThrottle: newAccountWriteThrottle(openAICodexSnapshotPersistMinInterval),
 	}
 	svc.logOpenAIWSModeBootstrap()
 	return svc
 }
 
+func (s *OpenAIGatewayService) getCodexSnapshotThrottle() *accountWriteThrottle {
+	if s != nil && s.codexSnapshotThrottle != nil {
+		return s.codexSnapshotThrottle
+	}
+	return defaultOpenAICodexSnapshotPersistThrottle
+}
+
 func (s *OpenAIGatewayService) billingDeps() *billingDeps {
 	return &billingDeps{
 		accountRepo:         s.accountRepo,
@@ -4164,11 +4215,15 @@ func (s *OpenAIGatewayService) updateCodexUsageSnapshot(ctx context.Context, acc
 	if len(updates) == 0 && resetAt == nil {
 		return
 	}
+	shouldPersistUpdates := len(updates) > 0 && s.getCodexSnapshotThrottle().Allow(accountID, now)
+	if !shouldPersistUpdates && resetAt == nil {
+		return
+	}
 
 	go func() {
 		updateCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 		defer cancel()
-		if len(updates) > 0 {
+		if shouldPersistUpdates {
 			_ = s.accountRepo.UpdateExtra(updateCtx, accountID, updates)
 		}
 		if resetAt != nil {

backend/internal/service/openai_ws_ratelimit_signal_test.go

@@ -405,6 +405,40 @@ func TestOpenAIGatewayService_UpdateCodexUsageSnapshot_NonExhaustedSnapshotDoesN
 	}
 }
 
+func TestOpenAIGatewayService_UpdateCodexUsageSnapshot_ThrottlesExtraWrites(t *testing.T) {
+	repo := &openAICodexSnapshotAsyncRepo{
+		updateExtraCh: make(chan map[string]any, 2),
+		rateLimitCh:   make(chan time.Time, 2),
+	}
+	svc := &OpenAIGatewayService{
+		accountRepo:           repo,
+		codexSnapshotThrottle: newAccountWriteThrottle(time.Hour),
+	}
+	snapshot := &OpenAICodexUsageSnapshot{
+		PrimaryUsedPercent:         ptrFloat64WS(94),
+		PrimaryResetAfterSeconds:   ptrIntWS(3600),
+		PrimaryWindowMinutes:       ptrIntWS(10080),
+		SecondaryUsedPercent:       ptrFloat64WS(22),
+		SecondaryResetAfterSeconds: ptrIntWS(1200),
+		SecondaryWindowMinutes:     ptrIntWS(300),
+	}
+
+	svc.updateCodexUsageSnapshot(context.Background(), 777, snapshot)
+	svc.updateCodexUsageSnapshot(context.Background(), 777, snapshot)
+
+	select {
+	case <-repo.updateExtraCh:
+	case <-time.After(2 * time.Second):
+		t.Fatal("等待第一次 codex 快照落库超时")
+	}
+
+	select {
+	case updates := <-repo.updateExtraCh:
+		t.Fatalf("unexpected second codex snapshot write: %v", updates)
+	case <-time.After(200 * time.Millisecond):
+	}
+}
+
 func ptrFloat64WS(v float64) *float64 { return &v }
 func ptrIntWS(v int) *int             { return &v }