first commit

internal/redisdao/notification.go

@@ -0,0 +1,89 @@
+package redisdao
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/global"
+	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/redismodel"
+	"github.com/redis/go-redis/v9"
+)
+
+// notificationUnreadTTL 未读数 key 的过期时间，避免长期驻留与 MySQL 弱一致漂移。
+const notificationUnreadTTL = 7 * 24 * time.Hour
+
+// notificationUnreadIncrScript 首次自增时设置过期时间，保证 INCR 与 EXPIRE 原子执行。
+var notificationUnreadIncrScript = redis.NewScript(`
+local v = redis.call('INCR', KEYS[1])
+if v == 1 then
+  redis.call('EXPIRE', KEYS[1], ARGV[1])
+end
+return v
+`)
+
+// notificationUnreadDecrScript 未读数 -1，保证结果不低于 0
+var notificationUnreadDecrScript = redis.NewScript(`
+local v = redis.call('GET', KEYS[1])
+if v and tonumber(v) > 0 then
+  return redis.call('DECRBY', KEYS[1], 1)
+end
+return 0
+`)
+
+// NotificationUnreadIncr 用户未读消息数 +1，返回最新值
+func NotificationUnreadIncr(ctx context.Context, userID int64) (int64, error) {
+	ctx, span := global.Tracer.Start(ctx, "redisdao.NotificationUnreadIncr")
+	defer span.End()
+
+	key := fmt.Sprintf(redismodel.KeyNotificationUnread, userID)
+	val, err := notificationUnreadIncrScript.Run(ctx, global.RedisEngine, []string{key}, int(notificationUnreadTTL.Seconds())).Int64()
+	if err != nil {
+		span.RecordError(err)
+		return 0, err
+	}
+	return val, nil
+}
+
+// NotificationUnreadDecr 用户未读消息数 -1，返回扣减后的值（不低于 0）
+func NotificationUnreadDecr(ctx context.Context, userID int64) (int64, error) {
+	ctx, span := global.Tracer.Start(ctx, "redisdao.NotificationUnreadDecr")
+	defer span.End()
+
+	key := fmt.Sprintf(redismodel.KeyNotificationUnread, userID)
+	val, err := notificationUnreadDecrScript.Run(ctx, global.RedisEngine, []string{key}).Int64()
+	if err != nil {
+		span.RecordError(err)
+		return 0, err
+	}
+	return val, nil
+}
+
+// NotificationUnreadGet 获取用户未读消息数，不存在时返回 0
+func NotificationUnreadGet(ctx context.Context, userID int64) (int64, error) {
+	ctx, span := global.Tracer.Start(ctx, "redisdao.NotificationUnreadGet")
+	defer span.End()
+
+	key := fmt.Sprintf(redismodel.KeyNotificationUnread, userID)
+	v, err := global.RedisEngine.Get(ctx, key).Int64()
+	if err == redis.Nil {
+		return 0, nil
+	}
+	if err != nil {
+		span.RecordError(err)
+	}
+	return v, err
+}
+
+// NotificationUnreadSet 回填未读数缓存（DB 对账回源后使用），避免 key 过期导致后续扣减被吞。
+func NotificationUnreadSet(ctx context.Context, userID int64, cnt int64) error {
+	ctx, span := global.Tracer.Start(ctx, "redisdao.NotificationUnreadSet")
+	defer span.End()
+
+	key := fmt.Sprintf(redismodel.KeyNotificationUnread, userID)
+	if err := global.RedisEngine.Set(ctx, key, cnt, notificationUnreadTTL).Err(); err != nil {
+		span.RecordError(err)
+		return err
+	}
+	return nil
+}