diagnostics_channel.hasSubscribers(name)

• name <string> | <symbol> 通道名称

  ¥name <string> | <symbol> The channel name

• 返回：<boolean> 如果有活跃订阅者

  ¥Returns: <boolean> If there are active subscribers

检查指定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 the named 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';

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

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