在 Laravel 6 中，当设置过期时间后，标签标识符键(‘tag:’.$name.’:key’)与标准引用键(:standard_ref)未自动过期的解决

1、现在存储被打上标签的缓存数据，打上了 1 个标签：theme_editor_qVnbtdW6HjsG5clEw6j6ygedgjrP4A9EDIsY

        return Cache::tags([
                ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId]
            )
            ->put(ThemePreviewInterface::THEME_EDITOR_SESSION_PREFIX . $sessionId, json_encode($data), ThemePreviewInterface::TTL);

2、运行程序以后，总计生成了 3 个 key，如图1

图1

object_local_database_object_local_cache:tag:theme_editor_qVnbtdW6HjsG5clEw6j6ygedgjrP4A9EDIsY:key

object_local_database_object_local_cache:63316a53e72ae936365540:standard_ref

object_local_database_object_local_cache:8900c8427a4e5d7ac70fed24623811c3b5330ddf:theme_editor_session:qVnbtdW6HjsG5clEw6j6ygedgjrP4A9EDIsY

3、过期时间设置为 120 秒，当 2 分钟之后，再次刷新 Redis，只有 key object_local_database_object_local_cache:8900c8427a4e5d7ac70fed24623811c3b5330ddf:theme_editor_session:qVnbtdW6HjsG5clEw6j6ygedgjrP4A9EDIsY 已经被自动删除掉。如图2

图2

4、相当于还剩下 2 个冗余的 key，皆是与 标签 相关的。决定在写入缓存时，将 2 个冗余的 key 皆设置过期时间。由于是使用的 Laravel 的 Redis 缓存。决定基于 Redis 设置过期时间来实现。

        Cache::tags([
                ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId]
            )
            ->put(ThemePreviewInterface::THEME_EDITOR_SESSION_PREFIX . $sessionId, json_encode($data), ThemePreviewInterface::TTL);
        $names = Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->getNames();
        var_dump($names);
        foreach ($names as $name) {
            var_dump(Cache::getPrefix() . Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->tagKey($name));
            var_dump(Redis::connection('cache')->command('expire', [Cache::getPrefix() . Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->tagKey($name), ThemePreviewInterface::TTL]));
            var_dump(Cache::getPrefix() . Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->tagId($name) . ':' . RedisTaggedCache::REFERENCE_KEY_STANDARD);
            var_dump(Redis::connection('cache')->command('expire', [Cache::getPrefix() . Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->tagId($name) . ':' . RedisTaggedCache::REFERENCE_KEY_STANDARD, ThemePreviewInterface::TTL]));
        }
        // var_dump(Cache::tags(ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId)->getTags()->getNames());
        // var_dump(Cache::getPrefix());
        exit;

5、打印结果如下。如图3

图3

array(1) {
  [0]=>
  string(49) "theme_editor_I37HieXlW2yzmNqWTwGsMoRu3vjivgpaGJ1T"
}
string(93) "object_local_cache:tag:theme_editor_I37HieXlW2yzmNqWTwGsMoRu3vjivgpaGJ1T:key"
bool(true)
string(71) "object_local_cache:63326932d41fb365623106:standard_ref"
bool(true)

6、Redis 中生成了 3 个 key，如图4

图4

object_local_database_object_local_cache:tag:theme_editor_I37HieXlW2yzmNqWTwGsMoRu3vjivgpaGJ1T:key
object_local_database_object_local_cache:63326932d41fb365623106:standard_ref
object_local_database_object_local_cache:59840c6d708feb22c6540bd14dbeb0c34bf4bbc4:theme_editor_session:I37HieXlW2yzmNqWTwGsMoRu3vjivgpaGJ1T

7、由于过期时间设置 120 秒，当 2 分钟过去后，Redis 中的数据从 12 条减少至 9 条。之前生成的 3 个 key 已经自动被删除。如图5

图5

8、最终实现代码如下

        $name = ThemePreviewInterface::TAG_THEME_EDITOR . '_' . $sessionId;
        $tags = Cache::tags($name);
        $result = $tags->put(ThemePreviewInterface::THEME_EDITOR_SESSION_PREFIX . $sessionId, json_encode($data), ThemePreviewInterface::TTL);
        if ($result) {
            Redis::connection('cache')->expire(Cache::getPrefix() . $tags->getTags()->tagKey($name), ThemePreviewInterface::TTL);
            Redis::connection('cache')->expire(Cache::getPrefix() . $tags->getTags()->tagId($name) . ':' . RedisTaggedCache::REFERENCE_KEY_STANDARD, ThemePreviewInterface::TTL);
        }

        return $result;