channel.hasSubscribers

• 返回：<boolean> 如果有活跃订阅者

  ¥Returns: <boolean> If there are active subscribers

检查此通道是否有活跃订阅者。如果你要发送的消息的准备成本可能很高，这将很有帮助。

¥Check if there are active subscribers to this channel. This is helpful if the message you want to send might be expensive to prepare.

此 API 是可选的，但在尝试从对性能非常敏感的代码发布消息时很有用。

¥This API is optional but helpful when trying to publish messages from very performance-sensitive code.

import diagnostics_channel from 'node:diagnostics_channel';

const channel = diagnostics_channel.channel('my-channel');

if (channel.hasSubscribers) {
  // There are subscribers, prepare and publish message
}const diagnostics_channel = require('node:diagnostics_channel');

const channel = diagnostics_channel.channel('my-channel');

if (channel.hasSubscribers) {
  // There are subscribers, prepare and publish message
}拷贝