Quick benchmarker for WordPress Plugin: SEO Auto Linker. For @danielbachhuber b/c it uses many preg_matches

benchmark_wordpress_seo-auto-linker.php

<?php
/*
 * Usage:
 * 1. Paste into Debug Bar console and Run
 * 2. Run it several times (just in case iTunes is running on your dev server)
 *
 * Benchmarking Alternatives:
 * - Wrap the real SEO Auto Linker for wp-cli and replace the call to content()
 * - Add this quick & dirty benchmark loop to Debug Bar 
 *
 */

// Get us some content to filter
$remote = wp_remote_get( 'http://www.danielbachhuber.com/' );
$content = $remote['body'];
    
// Repeat times
$repeat = 20;

// For the record
echo "Looping $repeat times<br /><br />";

// Time the preg_match way
$time_a1 = microtime( true );
echo "Start preg_match: $time_a1<br />";


// The real work
$filtered = null;
for ( $i = 0; $i < $repeat; $i++ ){
    $filtered .= content( $content );
}


// Timing output
$time_a2 = microtime( true );
echo "End preg_match: $time_a2<br /><br />";
echo "Total time: " . 1000 * ( $time_a2 - $time_a1 ) . "&nbsp;milliseconds<br />";
echo "Time per execution: " . 1000 * ( ( $time_a2 - $time_a1 ) / $repeat ) . "&nbsp;milliseconds<br /><br />";

echo "<h2>Original</h2>" . $content;
echo "<br /><br />";
echo "<h2>Filtered</h2>" . $filtered;



// -- Plugin Stubs--------------------------------------------------------------
// From SEO Auto Linker, http://wordpress.org/extend/plugins/seo-auto-linker/
// -----------------------------------------------------------------------------
function content( $content ) {

    $header_replacements = array();
    $link_replacements = array();
    $other_replacements = array();
    $shortcode_replacements = array();
    
    $filtered = $content;

    preg_match_all( '/' . get_shortcode_regex() . '/', $filtered, $scodes );
    if( ! empty( $scodes[0] ) ) {
        $shortcode_replacements = gen_replacements( $scodes[0], 'shortcode' );
        $filtered = replace( $shortcode_replacements, $filtered );
    }

    preg_match_all( '/<h[1-6][^>]*>.+?<\/h[1-6]>/iu', $filtered, $headers );
    if( ! empty( $headers[0] ) ) {
        $header_replacements = gen_replacements( $headers[0], 'header' );
        $filtered = replace( $header_replacements, $filtered );
    }

    preg_match_all( '/<(img|input)(.*?) \/?>/iu', $filtered, $others );
    if( ! empty( $others[0] ) ) {
        $other_replacements = gen_replacements( $others[0], 'others' );
        $filtered = replace( $other_replacements, $filtered );
    }

    // Not using Links post types, build here
    preg_match_all(
        '/<a(.*?)href="(.*?)"(.*?)>(.*?)<\/a>/iu',
        $filtered,
        $links
    );
    
    if( ! empty( $links[0] ) ) {
        $start = count( $link_replacements );
        $tmp = gen_replacements( $links[0], 'links', $start );
        $filtered = replace( $tmp, $filtered );
        $link_replacements = array_merge(
            $link_replacements,
            $tmp
        );
    }

    $regex = get_kw_regex();
    $url = 'http://www.danielbachhuber.com';
    $max = 1;
    if( ! $regex || !$url || !$max )
        continue;
    
    $target = '_self';
    $filtered = preg_replace(
        $regex,
        '$1<a href="' . esc_url( $url ) . '" title="$2" target="' . $target . '">$2</a>$3',
        $filtered,
        absint( $max )
    );

    return $filtered;
}


function replace( $arr, $content ) {
    return str_replace(
        array_values( $arr ),
        array_keys( $arr ),
        $content
    );
}

function gen_replacements( $arr, $key, $start = 0 ) {
    $hash = md5( 'seo-auto-linker' );
    $rv = array();
    $h = $hash;
    
    foreach( $arr as $a ) {
        $rv["<!--{$h}-{$key}-{$start}-->"] = $a;
        $start++;
    }
    
    return $rv;
}

function get_kw_regex() {
    $keywords = array(
                'wordpress',
                'post',
                'url',
                'test',
                'image',
                'hello',
                'world',
                'WordPress',
                'code',
                'git'
                );
    
    return sprintf( '/(\b)(%s)(\b)/ui', implode( '|', $keywords ) );
}