331 lines
10 KiB
Go
331 lines
10 KiB
Go
package repository
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import (
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"context"
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"errors"
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"fmt"
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"log"
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"math/rand/v2"
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"strconv"
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"time"
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"github.com/Wei-Shaw/sub2api/internal/service"
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"github.com/redis/go-redis/v9"
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)
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const (
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billingBalanceKeyPrefix = "billing:balance:"
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billingSubKeyPrefix = "billing:sub:"
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billingRateLimitKeyPrefix = "apikey:rate:"
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billingCacheTTL = 5 * time.Minute
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billingCacheJitter = 30 * time.Second
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rateLimitCacheTTL = 7 * 24 * time.Hour // 7 days matches the longest window
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// Rate limit window durations — must match service.RateLimitWindow* constants.
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rateLimitWindow5h = 5 * time.Hour
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rateLimitWindow1d = 24 * time.Hour
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rateLimitWindow7d = 7 * 24 * time.Hour
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)
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// jitteredTTL 返回带随机抖动的 TTL，防止缓存雪崩
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func jitteredTTL() time.Duration {
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// 只做“减法抖动”，确保实际 TTL 不会超过 billingCacheTTL（避免上界预期被打破）。
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if billingCacheJitter <= 0 {
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return billingCacheTTL
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}
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jitter := time.Duration(rand.IntN(int(billingCacheJitter)))
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return billingCacheTTL - jitter
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}
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// billingBalanceKey generates the Redis key for user balance cache.
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func billingBalanceKey(userID int64) string {
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return fmt.Sprintf("%s%d", billingBalanceKeyPrefix, userID)
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}
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// billingSubKey generates the Redis key for subscription cache.
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func billingSubKey(userID, groupID int64) string {
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return fmt.Sprintf("%s%d:%d", billingSubKeyPrefix, userID, groupID)
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}
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const (
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subFieldStatus = "status"
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subFieldExpiresAt = "expires_at"
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subFieldDailyUsage = "daily_usage"
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subFieldWeeklyUsage = "weekly_usage"
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subFieldMonthlyUsage = "monthly_usage"
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subFieldVersion = "version"
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)
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// billingRateLimitKey generates the Redis key for API key rate limit cache.
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func billingRateLimitKey(keyID int64) string {
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return fmt.Sprintf("%s%d", billingRateLimitKeyPrefix, keyID)
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}
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const (
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rateLimitFieldUsage5h = "usage_5h"
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rateLimitFieldUsage1d = "usage_1d"
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rateLimitFieldUsage7d = "usage_7d"
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rateLimitFieldWindow5h = "window_5h"
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rateLimitFieldWindow1d = "window_1d"
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rateLimitFieldWindow7d = "window_7d"
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)
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var (
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deductBalanceScript = redis.NewScript(`
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local current = redis.call('GET', KEYS[1])
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if current == false then
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return 0
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end
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local newVal = tonumber(current) - tonumber(ARGV[1])
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redis.call('SET', KEYS[1], newVal)
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redis.call('EXPIRE', KEYS[1], ARGV[2])
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return 1
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`)
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updateSubUsageScript = redis.NewScript(`
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local exists = redis.call('EXISTS', KEYS[1])
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if exists == 0 then
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return 0
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end
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local cost = tonumber(ARGV[1])
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redis.call('HINCRBYFLOAT', KEYS[1], 'daily_usage', cost)
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redis.call('HINCRBYFLOAT', KEYS[1], 'weekly_usage', cost)
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redis.call('HINCRBYFLOAT', KEYS[1], 'monthly_usage', cost)
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redis.call('EXPIRE', KEYS[1], ARGV[2])
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return 1
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`)
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// updateRateLimitUsageScript atomically increments all three rate limit usage counters
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// with window expiration checking. If a window has expired, its usage is reset to cost
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// (instead of accumulated) and the window timestamp is updated, matching the DB-side
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// IncrementRateLimitUsage semantics.
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//
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// ARGV: [1]=cost, [2]=ttl_seconds, [3]=now_unix, [4]=window_5h_seconds, [5]=window_1d_seconds, [6]=window_7d_seconds
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updateRateLimitUsageScript = redis.NewScript(`
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local exists = redis.call('EXISTS', KEYS[1])
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if exists == 0 then
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return 0
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end
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local cost = tonumber(ARGV[1])
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local now = tonumber(ARGV[3])
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local win5h = tonumber(ARGV[4])
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local win1d = tonumber(ARGV[5])
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local win7d = tonumber(ARGV[6])
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-- Helper: check if window is expired and update usage + window accordingly
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-- Returns nothing, modifies the hash in-place.
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local function update_window(usage_field, window_field, window_duration)
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local w = tonumber(redis.call('HGET', KEYS[1], window_field) or 0)
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if w == 0 or (now - w) >= window_duration then
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-- Window expired or never started: reset usage to cost, start new window
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redis.call('HSET', KEYS[1], usage_field, tostring(cost))
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redis.call('HSET', KEYS[1], window_field, tostring(now))
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else
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-- Window still valid: accumulate
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redis.call('HINCRBYFLOAT', KEYS[1], usage_field, cost)
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end
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end
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update_window('usage_5h', 'window_5h', win5h)
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update_window('usage_1d', 'window_1d', win1d)
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update_window('usage_7d', 'window_7d', win7d)
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redis.call('EXPIRE', KEYS[1], ARGV[2])
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return 1
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`)
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)
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type billingCache struct {
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rdb *redis.Client
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}
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func NewBillingCache(rdb *redis.Client) service.BillingCache {
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return &billingCache{rdb: rdb}
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}
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func (c *billingCache) GetUserBalance(ctx context.Context, userID int64) (float64, error) {
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key := billingBalanceKey(userID)
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val, err := c.rdb.Get(ctx, key).Result()
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if err != nil {
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return 0, err
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}
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return strconv.ParseFloat(val, 64)
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}
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func (c *billingCache) SetUserBalance(ctx context.Context, userID int64, balance float64) error {
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key := billingBalanceKey(userID)
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return c.rdb.Set(ctx, key, balance, jitteredTTL()).Err()
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}
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func (c *billingCache) DeductUserBalance(ctx context.Context, userID int64, amount float64) error {
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key := billingBalanceKey(userID)
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_, err := deductBalanceScript.Run(ctx, c.rdb, []string{key}, amount, int(jitteredTTL().Seconds())).Result()
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if err != nil && !errors.Is(err, redis.Nil) {
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log.Printf("Warning: deduct balance cache failed for user %d: %v", userID, err)
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return err
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}
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return nil
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}
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func (c *billingCache) InvalidateUserBalance(ctx context.Context, userID int64) error {
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key := billingBalanceKey(userID)
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return c.rdb.Del(ctx, key).Err()
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}
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func (c *billingCache) GetSubscriptionCache(ctx context.Context, userID, groupID int64) (*service.SubscriptionCacheData, error) {
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key := billingSubKey(userID, groupID)
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result, err := c.rdb.HGetAll(ctx, key).Result()
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if err != nil {
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return nil, err
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}
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if len(result) == 0 {
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return nil, redis.Nil
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}
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return c.parseSubscriptionCache(result)
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}
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func (c *billingCache) parseSubscriptionCache(data map[string]string) (*service.SubscriptionCacheData, error) {
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result := &service.SubscriptionCacheData{}
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result.Status = data[subFieldStatus]
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if result.Status == "" {
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return nil, errors.New("invalid cache: missing status")
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}
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if expiresStr, ok := data[subFieldExpiresAt]; ok {
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expiresAt, err := strconv.ParseInt(expiresStr, 10, 64)
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if err == nil {
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result.ExpiresAt = time.Unix(expiresAt, 0)
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}
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}
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if dailyStr, ok := data[subFieldDailyUsage]; ok {
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result.DailyUsage, _ = strconv.ParseFloat(dailyStr, 64)
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}
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if weeklyStr, ok := data[subFieldWeeklyUsage]; ok {
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result.WeeklyUsage, _ = strconv.ParseFloat(weeklyStr, 64)
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}
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if monthlyStr, ok := data[subFieldMonthlyUsage]; ok {
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result.MonthlyUsage, _ = strconv.ParseFloat(monthlyStr, 64)
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}
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if versionStr, ok := data[subFieldVersion]; ok {
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result.Version, _ = strconv.ParseInt(versionStr, 10, 64)
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}
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return result, nil
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}
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func (c *billingCache) SetSubscriptionCache(ctx context.Context, userID, groupID int64, data *service.SubscriptionCacheData) error {
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if data == nil {
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return nil
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}
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key := billingSubKey(userID, groupID)
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fields := map[string]any{
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subFieldStatus: data.Status,
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subFieldExpiresAt: data.ExpiresAt.Unix(),
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subFieldDailyUsage: data.DailyUsage,
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subFieldWeeklyUsage: data.WeeklyUsage,
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subFieldMonthlyUsage: data.MonthlyUsage,
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subFieldVersion: data.Version,
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}
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pipe := c.rdb.Pipeline()
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pipe.HSet(ctx, key, fields)
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pipe.Expire(ctx, key, jitteredTTL())
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_, err := pipe.Exec(ctx)
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return err
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}
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func (c *billingCache) UpdateSubscriptionUsage(ctx context.Context, userID, groupID int64, cost float64) error {
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key := billingSubKey(userID, groupID)
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_, err := updateSubUsageScript.Run(ctx, c.rdb, []string{key}, cost, int(jitteredTTL().Seconds())).Result()
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if err != nil && !errors.Is(err, redis.Nil) {
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log.Printf("Warning: update subscription usage cache failed for user %d group %d: %v", userID, groupID, err)
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return err
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}
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return nil
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}
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func (c *billingCache) InvalidateSubscriptionCache(ctx context.Context, userID, groupID int64) error {
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key := billingSubKey(userID, groupID)
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return c.rdb.Del(ctx, key).Err()
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}
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func (c *billingCache) GetAPIKeyRateLimit(ctx context.Context, keyID int64) (*service.APIKeyRateLimitCacheData, error) {
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key := billingRateLimitKey(keyID)
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result, err := c.rdb.HGetAll(ctx, key).Result()
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if err != nil {
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return nil, err
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}
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if len(result) == 0 {
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return nil, redis.Nil
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}
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data := &service.APIKeyRateLimitCacheData{}
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if v, ok := result[rateLimitFieldUsage5h]; ok {
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data.Usage5h, _ = strconv.ParseFloat(v, 64)
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}
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if v, ok := result[rateLimitFieldUsage1d]; ok {
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data.Usage1d, _ = strconv.ParseFloat(v, 64)
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}
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if v, ok := result[rateLimitFieldUsage7d]; ok {
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data.Usage7d, _ = strconv.ParseFloat(v, 64)
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}
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if v, ok := result[rateLimitFieldWindow5h]; ok {
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data.Window5h, _ = strconv.ParseInt(v, 10, 64)
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}
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if v, ok := result[rateLimitFieldWindow1d]; ok {
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data.Window1d, _ = strconv.ParseInt(v, 10, 64)
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}
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if v, ok := result[rateLimitFieldWindow7d]; ok {
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data.Window7d, _ = strconv.ParseInt(v, 10, 64)
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}
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return data, nil
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}
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func (c *billingCache) SetAPIKeyRateLimit(ctx context.Context, keyID int64, data *service.APIKeyRateLimitCacheData) error {
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if data == nil {
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return nil
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}
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key := billingRateLimitKey(keyID)
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fields := map[string]any{
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rateLimitFieldUsage5h: data.Usage5h,
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rateLimitFieldUsage1d: data.Usage1d,
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rateLimitFieldUsage7d: data.Usage7d,
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rateLimitFieldWindow5h: data.Window5h,
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rateLimitFieldWindow1d: data.Window1d,
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rateLimitFieldWindow7d: data.Window7d,
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}
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pipe := c.rdb.Pipeline()
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pipe.HSet(ctx, key, fields)
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pipe.Expire(ctx, key, rateLimitCacheTTL)
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_, err := pipe.Exec(ctx)
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return err
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}
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func (c *billingCache) UpdateAPIKeyRateLimitUsage(ctx context.Context, keyID int64, cost float64) error {
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key := billingRateLimitKey(keyID)
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now := time.Now().Unix()
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_, err := updateRateLimitUsageScript.Run(ctx, c.rdb, []string{key},
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cost,
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int(rateLimitCacheTTL.Seconds()),
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now,
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int(rateLimitWindow5h.Seconds()),
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int(rateLimitWindow1d.Seconds()),
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int(rateLimitWindow7d.Seconds()),
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).Result()
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if err != nil && !errors.Is(err, redis.Nil) {
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log.Printf("Warning: update rate limit usage cache failed for api key %d: %v", keyID, err)
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return err
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}
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return nil
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}
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func (c *billingCache) InvalidateAPIKeyRateLimit(ctx context.Context, keyID int64) error {
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key := billingRateLimitKey(keyID)
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return c.rdb.Del(ctx, key).Err()
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}
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