WordPress at a glance
function is not described

wp_get_post_autosave() WP 2.6.0

Retrieve the autosaved data of the specified post.

Returns a post object containing the information that was autosaved for the specified post. If the optional $user_id is passed, returns the autosave for that user otherwise returns the latest autosave.

No Hooks.

Return

WP_Post/false. The autosaved data or false on failure or when no autosave exists.

Usage

wp_get_post_autosave( $post_id, $user_id );
$post_id(int) (required)
The post ID.
$user_id(int)
Optional The post author ID.
Default: 0

Changelog

Since 2.6.0 Introduced.

Code of wp get post autosave: wp-includes/revision.php WP 5.2.2

<?php
function wp_get_post_autosave( $post_id, $user_id = 0 ) {
	$revisions = wp_get_post_revisions( $post_id, array( 'check_enabled' => false ) );

	foreach ( $revisions as $revision ) {
		if ( false !== strpos( $revision->post_name, "{$post_id}-autosave" ) ) {
			if ( $user_id && $user_id != $revision->post_author ) {
				continue;
			}

			return $revision;
		}
	}

	return false;
}