Profile a modified version of `locate_template` to see if we can speed it up.

README.md

Benchmark for locate_template

Profile a modified version of locate_template to see if we can speed it up.

This is used to benchmark the patch introduced for Trac ticket #40731.

Results of the benchmark are found in a shared Google Sheet.

profile-locate_template.php

<?php

// Bootstrapping.

define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require ('wp-load.php');

// Setup.

$urls = [
	[ 'front-page.php' ],
	[ 'home.php', 'index.php' ],
	[ 'header.php' ],
	[ 'template-parts/header/site-header.php' ],
	[ 'template-parts/header/site-branding.php' ],
	[ 'template-parts/header/site-nav.php' ],
	[ 'template-parts/content/content-excerpt.php', 'template-parts/content/content.php' ],
	[ 'template-parts/header/excerpt-header.php' ],
	[ 'template-parts/excerpt/excerpt.php' ],
	[ 'footer.php' ],
	[ 'template-parts/footer/footer-widgets.php' ],
];

$urls2 = [
	[ 'front-page-2.php' ],
	[ 'home-2.php', 'index-2.php' ],
	[ 'header-2.php' ],
	[ 'template-parts-2/header/site-header.php' ],
	[ 'template-parts-2/header/site-branding.php' ],
	[ 'template-parts-2/header/site-nav.php' ],
	[ 'template-parts-2/content/content-excerpt.php', 'template-parts-2/content/content.php' ],
	[ 'template-parts-2/header/excerpt-header.php' ],
	[ 'template-parts-2/excerpt/excerpt.php' ],
	[ 'footer-2.php' ],
	[ 'template-parts-2/footer/footer-widgets.php' ],
];

$repetitions = 10;
$iterations  = 11;

$stringcount = count( $urls );

function microtime_float() {
	list( $usec, $sec ) = explode( ' ', microtime() );
	return ( (float) $usec + (float) $sec );
}

// Refactoring functions.
function new_locate_template( $template_names, $load = false, $require_once = true, $args = array() ) {
	$located = '';

	static $template_cache = array();
	foreach ( (array) $template_names as $template_name ) {
		if ( ! $template_name ) {
			continue;
		}

		if ( isset( $template_cache[ $template_name ] ) ) {
			if ( '' === $template_cache[ $template_name ] ) {
				continue;
			}
		
			$located = $template_cache[ $template_name ];
			break;
		}

		if ( file_exists( STYLESHEETPATH . '/' . $template_name ) ) {
			$located = $template_cache[$template_name] = STYLESHEETPATH . '/' . $template_name;
			break;
		} elseif ( file_exists( TEMPLATEPATH . '/' . $template_name ) ) {
			$located = $template_cache[$template_name] = TEMPLATEPATH . '/' . $template_name;
			break;
		} elseif ( file_exists( ABSPATH . WPINC . '/theme-compat/' . $template_name ) ) {
			$located = $template_cache[$template_name] = ABSPATH . WPINC . '/theme-compat/' . $template_name;
			break;
		}
		$template_cache[$template_name] = '';
	}

	if ( $load && '' !== $located ) {
		load_template( $located, $require_once, $args );
	}
	return $located;
}

// Profiling.

for ( $repetition = 0; $repetition <= $repetitions; $repetition ++ ) {

	if( $repetition == 0 ) {
		continue;
	}

	$time_start = microtime_float();

	for ( $index = 0; $index < $iterations; $index ++ ) {
		$url    = $urls[ $index % $stringcount ];
		$result = locate_template( $url );
	}

	$time_end                    = microtime_float();
	$locate_template_time[ $repetition ] = $time_end - $time_start;

	$time_start = microtime_float();

	for ( $index = 0; $index < $iterations; $index ++ ) {
		$url    = $urls2[ $index % $stringcount ];
		$result = new_locate_template( $url );
	}

	$time_end                        = microtime_float();
	$new_locate_template_time[ $repetition ] = $time_end - $time_start;
}

$locate_template_time_avg     = array_sum( $locate_template_time ) / $repetitions;
$new_locate_template_time_avg = array_sum( $new_locate_template_time ) / $repetitions;
$percentage           = round( $new_locate_template_time_avg / $locate_template_time_avg * 100, 1 ) - 100;

printf( "Average time spent for ${repetitions} x ${iterations} iterations:\n    locate_template() - ${locate_template_time_avg}\nnew_locate_template() - ${new_locate_template_time_avg}\n\nChange: ${percentage}%%\n" );