云策 WordPress 开发者社区

函数文档

wp_cache_set_last_changed()

查看官方原文 ↗
💡 云策文档标注

概述

wp_cache_set_last_changed() 函数用于将指定缓存组的最后更改时间设置为当前时间，并返回UNIX时间戳。它通过更新缓存中的 'last_changed' 键值来实现，并触发一个动作钩子。

关键要点

  • 函数参数：$group（字符串，必需），指定缓存组名。
  • 返回值：字符串，表示缓存组最后更改的UNIX时间戳。
  • 内部流程：先获取之前的 'last_changed' 时间，然后使用 microtime() 设置新时间，并调用 wp_cache_set() 更新缓存。
  • 钩子：do_action('wp_cache_set_last_changed', $group, $time, $previous_time)，在更新后触发，允许开发者执行相关操作。
  • 相关函数：与 wp_cache_set()、wp_cache_get() 和 wp_cache_get_last_changed() 等缓存函数协同工作。
  • 使用场景：常用于用户、站点、分类、评论和文章等缓存组的最后更改时间管理。
  • 版本历史：自 WordPress 6.3.0 版本引入。

代码示例

function wp_cache_set_last_changed( $group ) {
    $previous_time = wp_cache_get( 'last_changed', $group );

    $time = microtime();

    wp_cache_set( 'last_changed', $time, $group );

    do_action( 'wp_cache_set_last_changed', $group, $time, $previous_time );

    return $time;
}

注意事项

  • 此函数可能在每个页面加载中多次调用，注册的动作必须高效，以避免性能问题。
  • 钩子参数包括缓存组名、新时间戳和之前的时间戳（如果未设置则为 false）。
📄 原文内容

Sets last changed date for the specified cache group to now.

Parameters

$groupstringrequired
Where the cache contents are grouped.

Return

string UNIX timestamp when the group was last changed.

Source

function wp_cache_set_last_changed( $group ) {
	$previous_time = wp_cache_get( 'last_changed', $group );

	$time = microtime();

	wp_cache_set( 'last_changed', $time, $group );

	/**
	 * Fires after a cache group `last_changed` time is updated.
	 * This may occur multiple times per page load and registered
	 * actions must be performant.
	 *
	 * @since 6.3.0
	 *
	 * @param string       $group         The cache group name.
	 * @param string       $time          The new last changed time (msec sec).
	 * @param string|false $previous_time The previous last changed time. False if not previously set.
	 */
	do_action( 'wp_cache_set_last_changed', $group, $time, $previous_time );

	return $time;
}

View all references View on Trac View on GitHub

Hooks

do_action( ‘wp_cache_set_last_changed’, string $group, string $time, string|false $previous_time )

Fires after a cache group last_changed time is updated.

Uses Description
wp_cache_set()wp-includes/cache.php

Saves the data to the cache.
wp_cache_get()wp-includes/cache.php

Retrieves the cache contents from the cache by key and group.
do_action()wp-includes/plugin.php

Calls the callback functions that have been added to an action hook.

Show 1 moreShow less

Used by Description
wp_cache_set_users_last_changed()wp-includes/user.php

Sets the last changed time for the ‘users’ cache group.
wp_cache_set_sites_last_changed()wp-includes/ms-site.php

Sets the last changed time for the ‘sites’ cache group.
wp_cache_set_terms_last_changed()wp-includes/taxonomy.php

Sets the last changed time for the ‘terms’ cache group.
wp_cache_set_comments_last_changed()wp-includes/comment.php

Sets the last changed time for the ‘comment’ cache group.
wp_cache_set_posts_last_changed()wp-includes/post.php

Sets the last changed time for the ‘posts’ cache group.
wp_cache_get_last_changed()wp-includes/functions.php

Gets last changed date for the specified cache group.
clean_network_cache()wp-includes/ms-network.php

Removes a network from the object cache.

Show 2 moreShow less

Changelog

Version Description
6.3.0 Introduced.