do_trackbacks( int|WP_Post $post ): void|false

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$postint|WP_Post

Post ID or object to do trackbacks on.

Return value

void|false

Returns false on failure.

Performance profile

How much work a call to do_trackbacks() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Expensive

Reaches an outbound HTTP request via wp_safe_remote_post().

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

8–59

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 108.

Plugin surface

3 hooks

Third-party callbacks on 'the_content', 'the_excerpt', 'the_title' run inside this call, and their cost is not bounded by anything here.

Called by

1

1 place in core call this, so the cost is paid more often than your own code shows.

What it touches

• querycontent queryget_post()called directly
• hookthird-party callbacksapply_filters()called directly
• optionoption read or writeget_option()one call below do_trackbacks()
• httpoutbound HTTP requestwp_safe_remote_post()one call below do_trackbacks()

Further down the call graph this can also reach cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 3 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost do_trackbacks() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 3

3 hooks fire while do_trackbacks() runs, in this order:

1. 1
   apply_filters( the_content )filterline 3044 (+19 into the body)

   Filters the post content.

2. 2
   apply_filters( the_excerpt )filterline 3047 (+22 into the body)

   Filters the displayed post excerpt.

3. 3
   apply_filters( the_title )filterline 3054 (+29 into the body)

   Filters the post title.

Uses · 6

• get_post()Retrieves post data given a post ID or post object.
• get_to_ping()Retrieves URLs that need to be pinged.
• get_pung()Retrieves URLs already pinged for a post.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_html_excerpt()Safely extracts not more than the first $count characters from HTML string.
• trackback()Sends a Trackback.

Used by · 1

• do_all_trackbacks()Performs all trackbacks.

Source code

View on Trac ↗View on GitHub ↗

3025function do_trackbacks( $post ) {3026	global $wpdb;3027 3028	$post = get_post( $post );3029 3030	if ( ! $post ) {3031		return false;3032	}3033 3034	$to_ping = get_to_ping( $post );3035	$pinged  = get_pung( $post );3036 3037	if ( empty( $to_ping ) ) {3038		$wpdb->update( $wpdb->posts, array( 'to_ping' => '' ), array( 'ID' => $post->ID ) );3039		return;3040	}3041 3042	if ( empty( $post->post_excerpt ) ) {3043		/** This filter is documented in wp-includes/post-template.php */3044		$excerpt = apply_filters( 'the_content', $post->post_content, $post->ID );3045	} else {3046		/** This filter is documented in wp-includes/post-template.php */3047		$excerpt = apply_filters( 'the_excerpt', $post->post_excerpt );3048	}3049 3050	$excerpt = str_replace( ']]>', ']]>', $excerpt );3051	$excerpt = wp_html_excerpt( $excerpt, 252, '…' );3052 3053	/** This filter is documented in wp-includes/post-template.php */3054	$post_title = apply_filters( 'the_title', $post->post_title, $post->ID );3055	$post_title = strip_tags( $post_title );3056 3057	if ( $to_ping ) {3058		foreach ( (array) $to_ping as $tb_ping ) {3059			$tb_ping = trim( $tb_ping );3060			if ( ! in_array( $tb_ping, $pinged, true ) ) {3061				trackback( $tb_ping, $post_title, $excerpt, $post->ID );3062				$pinged[] = $tb_ping;3063			} else {3064				$wpdb->query(3065					$wpdb->prepare(3066						"UPDATE $wpdb->posts SET to_ping = TRIM(REPLACE(to_ping, %s,3067					'')) WHERE ID = %d",3068						$tb_ping,3069						$post->ID3070					)3071				);3072			}3073		}3074	}3075}

Changelog

Introduced in 1.5.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.8.8 tag, from src/wp-includes/comment.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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