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function is not described

_count_posts_cache_key() WP 3.9.0

Return the cache key for wp_count_posts() based on the passed arguments.

This is an internal function for using it by WP core itself. It's not recommended to use this function in your code.

No Hooks.

Return

String. The cache key.

Usage

_count_posts_cache_key( $type, $perm );
$type(string)
Post type to retrieve count Default 'post'.
$perm(string)
'readable' or empty.
Default: ''

Changelog

Since 3.9.0 Introduced.

Code of _count_posts_cache_key() WP 5.7.1

<?php
function _count_posts_cache_key( $type = 'post', $perm = '' ) {
	$cache_key = 'posts-' . $type;

	if ( 'readable' === $perm && is_user_logged_in() ) {
		$post_type_object = get_post_type_object( $type );

		if ( $post_type_object && ! current_user_can( $post_type_object->cap->read_private_posts ) ) {
			$cache_key .= '_' . $perm . '_' . get_current_user_id();
		}
	}

	return $cache_key;
}