fix: Anthropic 429 限流使用精确的窗口重置时间而非聚合最大值

当账号仅触发 5h 窗口限流时，旧逻辑从聚合头 anthropic-ratelimit-unified-reset 读取重置时间，该值为所有窗口的最大值（即 7d 重置时间），导致账号被标记为不可调度约 6 天。新增 calculateAnthropic429ResetTime 函数，解析 Anthropic 的 per-window 头（5h-utilization/reset、7d-utilization/reset、 surpassed-threshold），判断实际触发的窗口并使用对应的重置时间： - 仅 5h 超标 → 使用 5h-reset（约 5 小时） - 仅 7d 超标 → 使用 7d-reset - 两者均超标 → 使用 7d-reset（较长冷却） - per-window 头不存在 → 回退到聚合头（向后兼容）
2026-02-14 00:21:56 +08:00
parent 471943269c
commit e681431454
2 changed files with 331 additions and 2 deletions
--- a/backend/internal/service/ratelimit_service.go
+++ b/backend/internal/service/ratelimit_service.go
@@ -381,10 +381,31 @@ func (s *RateLimitService) handle429(ctx context.Context, account *Account, head
 		}
 	}

-	// 2. 尝试从响应头解析重置时间（Anthropic）
+	// 2. Anthropic 平台：尝试解析 per-window 头（5h / 7d），选择实际触发的窗口
+	if result := calculateAnthropic429ResetTime(headers); result != nil {
+		if err := s.accountRepo.SetRateLimited(ctx, account.ID, result.resetAt); err != nil {
+			slog.Warn("rate_limit_set_failed", "account_id", account.ID, "error", err)
+			return
+		}
+
+		// 更新 session window：优先使用 5h-reset 头精确计算，否则从 resetAt 反推
+		windowEnd := result.resetAt
+		if result.fiveHourReset != nil {
+			windowEnd = *result.fiveHourReset
+		}
+		windowStart := windowEnd.Add(-5 * time.Hour)
+		if err := s.accountRepo.UpdateSessionWindow(ctx, account.ID, &windowStart, &windowEnd, "rejected"); err != nil {
+			slog.Warn("rate_limit_update_session_window_failed", "account_id", account.ID, "error", err)
+		}
+
+		slog.Info("anthropic_account_rate_limited", "account_id", account.ID, "reset_at", result.resetAt, "reset_in", time.Until(result.resetAt).Truncate(time.Second))
+		return
+	}
+
+	// 3. 尝试从响应头解析重置时间（Anthropic 聚合头，向后兼容）
 	resetTimestamp := headers.Get("anthropic-ratelimit-unified-reset")

-	// 3. 如果响应头没有，尝试从响应体解析（OpenAI usage_limit_reached, Gemini）
+	// 4. 如果响应头没有，尝试从响应体解析（OpenAI usage_limit_reached, Gemini）
 	if resetTimestamp == "" {
 		switch account.Platform {
 		case PlatformOpenAI:
@@ -497,6 +518,112 @@ func (s *RateLimitService) calculateOpenAI429ResetTime(headers http.Header) *tim
 	return nil
 }

+// anthropic429Result holds the parsed Anthropic 429 rate-limit information.
+type anthropic429Result struct {
+	resetAt       time.Time  // The correct reset time to use for SetRateLimited
+	fiveHourReset *time.Time // 5h window reset timestamp (for session window calculation), nil if not available
+}
+
+// calculateAnthropic429ResetTime parses Anthropic's per-window rate-limit headers
+// to determine which window (5h or 7d) actually triggered the 429.
+//
+// Headers used:
+//   - anthropic-ratelimit-unified-5h-utilization / anthropic-ratelimit-unified-5h-surpassed-threshold
+//   - anthropic-ratelimit-unified-5h-reset
+//   - anthropic-ratelimit-unified-7d-utilization / anthropic-ratelimit-unified-7d-surpassed-threshold
+//   - anthropic-ratelimit-unified-7d-reset
+//
+// Returns nil when the per-window headers are absent (caller should fall back to
+// the aggregated anthropic-ratelimit-unified-reset header).
+func calculateAnthropic429ResetTime(headers http.Header) *anthropic429Result {
+	reset5hStr := headers.Get("anthropic-ratelimit-unified-5h-reset")
+	reset7dStr := headers.Get("anthropic-ratelimit-unified-7d-reset")
+
+	if reset5hStr == "" && reset7dStr == "" {
+		return nil
+	}
+
+	var reset5h, reset7d *time.Time
+	if ts, err := strconv.ParseInt(reset5hStr, 10, 64); err == nil {
+		t := time.Unix(ts, 0)
+		reset5h = &t
+	}
+	if ts, err := strconv.ParseInt(reset7dStr, 10, 64); err == nil {
+		t := time.Unix(ts, 0)
+		reset7d = &t
+	}
+
+	is5hExceeded := isAnthropicWindowExceeded(headers, "5h")
+	is7dExceeded := isAnthropicWindowExceeded(headers, "7d")
+
+	slog.Info("anthropic_429_window_analysis",
+		"is_5h_exceeded", is5hExceeded,
+		"is_7d_exceeded", is7dExceeded,
+		"reset_5h", reset5hStr,
+		"reset_7d", reset7dStr,
+	)
+
+	// Select the correct reset time based on which window(s) are exceeded.
+	var chosen *time.Time
+	switch {
+	case is5hExceeded && is7dExceeded:
+		// Both exceeded → prefer 7d (longer cooldown), fall back to 5h
+		chosen = reset7d
+		if chosen == nil {
+			chosen = reset5h
+		}
+	case is5hExceeded:
+		chosen = reset5h
+	case is7dExceeded:
+		chosen = reset7d
+	default:
+		// Neither flag clearly exceeded — pick the sooner reset as best guess
+		chosen = pickSooner(reset5h, reset7d)
+	}
+
+	if chosen == nil {
+		return nil
+	}
+	return &anthropic429Result{resetAt: *chosen, fiveHourReset: reset5h}
+}
+
+// isAnthropicWindowExceeded checks whether a given Anthropic rate-limit window
+// (e.g. "5h" or "7d") has been exceeded, using utilization and surpassed-threshold headers.
+func isAnthropicWindowExceeded(headers http.Header, window string) bool {
+	prefix := "anthropic-ratelimit-unified-" + window + "-"
+
+	// Check surpassed-threshold first (most explicit signal)
+	if st := headers.Get(prefix + "surpassed-threshold"); strings.EqualFold(st, "true") {
+		return true
+	}
+
+	// Fall back to utilization >= 1.0
+	if utilStr := headers.Get(prefix + "utilization"); utilStr != "" {
+		if util, err := strconv.ParseFloat(utilStr, 64); err == nil && util >= 1.0-1e-9 {
+			// Use a small epsilon to handle floating point: treat 0.9999999... as >= 1.0
+			return true
+		}
+	}
+
+	return false
+}
+
+// pickSooner returns whichever of the two time pointers is earlier.
+// If only one is non-nil, it is returned. If both are nil, returns nil.
+func pickSooner(a, b *time.Time) *time.Time {
+	switch {
+	case a != nil && b != nil:
+		if a.Before(*b) {
+			return a
+		}
+		return b
+	case a != nil:
+		return a
+	default:
+		return b
+	}
+}
+
 // parseOpenAIRateLimitResetTime 解析 OpenAI 格式的 429 响应，返回重置时间的 Unix 时间戳
 // OpenAI 的 usage_limit_reached 错误格式：
 //
--- a/backend/internal/service/ratelimit_service_anthropic_test.go
+++ b/backend/internal/service/ratelimit_service_anthropic_test.go
@@ -0,0 +1,202 @@
+package service
+
+import (
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestCalculateAnthropic429ResetTime_Only5hExceeded(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "1.02")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "0.32")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1770998400)
+
+	if result.fiveHourReset == nil || !result.fiveHourReset.Equal(time.Unix(1770998400, 0)) {
+		t.Errorf("expected fiveHourReset=1770998400, got %v", result.fiveHourReset)
+	}
+}
+
+func TestCalculateAnthropic429ResetTime_Only7dExceeded(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "0.50")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "1.05")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1771549200)
+
+	// fiveHourReset should still be populated for session window calculation
+	if result.fiveHourReset == nil || !result.fiveHourReset.Equal(time.Unix(1770998400, 0)) {
+		t.Errorf("expected fiveHourReset=1770998400, got %v", result.fiveHourReset)
+	}
+}
+
+func TestCalculateAnthropic429ResetTime_BothExceeded(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "1.10")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "1.02")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1771549200)
+}
+
+func TestCalculateAnthropic429ResetTime_NoPerWindowHeaders(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	if result != nil {
+		t.Errorf("expected nil result when no per-window headers, got resetAt=%v", result.resetAt)
+	}
+}
+
+func TestCalculateAnthropic429ResetTime_NoHeaders(t *testing.T) {
+	result := calculateAnthropic429ResetTime(http.Header{})
+	if result != nil {
+		t.Errorf("expected nil result for empty headers, got resetAt=%v", result.resetAt)
+	}
+}
+
+func TestCalculateAnthropic429ResetTime_SurpassedThreshold(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-surpassed-threshold", "true")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+	headers.Set("anthropic-ratelimit-unified-7d-surpassed-threshold", "false")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1770998400)
+}
+
+func TestCalculateAnthropic429ResetTime_UtilizationExactlyOne(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "1.0")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "0.5")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1770998400)
+}
+
+func TestCalculateAnthropic429ResetTime_NeitherExceeded_UsesShorter(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "0.95")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400") // sooner
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "0.80")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200") // later
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1770998400)
+}
+
+func TestCalculateAnthropic429ResetTime_Only5hResetHeader(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-5h-utilization", "1.05")
+	headers.Set("anthropic-ratelimit-unified-5h-reset", "1770998400")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1770998400)
+}
+
+func TestCalculateAnthropic429ResetTime_Only7dResetHeader(t *testing.T) {
+	headers := http.Header{}
+	headers.Set("anthropic-ratelimit-unified-7d-utilization", "1.03")
+	headers.Set("anthropic-ratelimit-unified-7d-reset", "1771549200")
+
+	result := calculateAnthropic429ResetTime(headers)
+	assertAnthropicResult(t, result, 1771549200)
+
+	if result.fiveHourReset != nil {
+		t.Errorf("expected fiveHourReset=nil when no 5h headers, got %v", result.fiveHourReset)
+	}
+}
+
+func TestIsAnthropicWindowExceeded(t *testing.T) {
+	tests := []struct {
+		name     string
+		headers  http.Header
+		window   string
+		expected bool
+	}{
+		{
+			name:     "utilization above 1.0",
+			headers:  makeHeader("anthropic-ratelimit-unified-5h-utilization", "1.02"),
+			window:   "5h",
+			expected: true,
+		},
+		{
+			name:     "utilization exactly 1.0",
+			headers:  makeHeader("anthropic-ratelimit-unified-5h-utilization", "1.0"),
+			window:   "5h",
+			expected: true,
+		},
+		{
+			name:     "utilization below 1.0",
+			headers:  makeHeader("anthropic-ratelimit-unified-5h-utilization", "0.99"),
+			window:   "5h",
+			expected: false,
+		},
+		{
+			name:     "surpassed-threshold true",
+			headers:  makeHeader("anthropic-ratelimit-unified-7d-surpassed-threshold", "true"),
+			window:   "7d",
+			expected: true,
+		},
+		{
+			name:     "surpassed-threshold True (case insensitive)",
+			headers:  makeHeader("anthropic-ratelimit-unified-7d-surpassed-threshold", "True"),
+			window:   "7d",
+			expected: true,
+		},
+		{
+			name:     "surpassed-threshold false",
+			headers:  makeHeader("anthropic-ratelimit-unified-7d-surpassed-threshold", "false"),
+			window:   "7d",
+			expected: false,
+		},
+		{
+			name:     "no headers",
+			headers:  http.Header{},
+			window:   "5h",
+			expected: false,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := isAnthropicWindowExceeded(tc.headers, tc.window)
+			if got != tc.expected {
+				t.Errorf("expected %v, got %v", tc.expected, got)
+			}
+		})
+	}
+}
+
+// assertAnthropicResult is a test helper that verifies the result is non-nil and
+// has the expected resetAt unix timestamp.
+func assertAnthropicResult(t *testing.T, result *anthropic429Result, wantUnix int64) {
+	t.Helper()
+	if result == nil {
+		t.Fatal("expected non-nil result")
+		return // unreachable, but satisfies staticcheck SA5011
+	}
+	want := time.Unix(wantUnix, 0)
+	if !result.resetAt.Equal(want) {
+		t.Errorf("expected resetAt=%v, got %v", want, result.resetAt)
+	}
+}
+
+func makeHeader(key, value string) http.Header {
+	h := http.Header{}
+	h.Set(key, value)
+	return h
+}