wp-includes/post.php:3497Counts number of attachments for the mime type(s).
$mime_typestring|string[]optional''stdClassOne hook fires while wp_count_attachments() runs, in this order:
Filters the attachment counts by mime type.
function wp_count_attachments( $mime_type = '' ) { global $wpdb; $cache_key = sprintf( 'attachments%s', ! empty( $mime_type ) ? ':' . str_replace( '/', '_', implode( '-', (array) $mime_type ) ) : '' ); $counts = wp_cache_get( $cache_key, 'counts' ); if ( false === $counts ) { $and = wp_post_mime_type_where( $mime_type ); $count = $wpdb->get_results( "SELECT post_mime_type, COUNT( * ) AS num_posts FROM $wpdb->posts WHERE post_type = 'attachment' AND post_status != 'trash' $and GROUP BY post_mime_type", ARRAY_A ); $counts = array(); foreach ( (array) $count as $row ) { $counts[ $row['post_mime_type'] ] = $row['num_posts']; } $counts['trash'] = $wpdb->get_var( "SELECT COUNT( * ) FROM $wpdb->posts WHERE post_type = 'attachment' AND post_status = 'trash' $and" ); wp_cache_set( $cache_key, (object) $counts, 'counts' ); } /** * Filters the attachment counts by mime type. * * @since 3.7.0 * * @param stdClass $counts An object containing the attachment counts by * mime type. * @param string|string[] $mime_type Array or comma-separated list of MIME patterns. */ return apply_filters( 'wp_count_attachments', (object) $counts, $mime_type );}Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/post.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.