Testing script to compare proposed new method of getting non-affiliate, and affiliate users.

database-comparison-test.php

<?php
add_filter( 'wp_is_large_network', '__return_false' );

/**
 * Calculates the time needed to run the specified function.
 * @param     $function        string The callback to run.
 * @param     $args            array Array of arguments to pass.
 * @param int $number_of_times int The number of times this function should run.
 * @return mixed
 */
function get_time_to_run_function( $function, $args, $number_of_times = 1 ) {
	set_time_limit( 0 );
	ini_set( 'memory_limit', '4096M' );
	$benchmarks = array();
	$start      = microtime( true );
	$i          = 0;
	while( $i < $number_of_times ){
		$result       = call_user_func_array( $function, $args );
		$benchmarks[] = array( 'time' => microtime( true ) - $start, 'result' => $result );
		$i ++;
	}

	return $benchmarks;
}

/**
 * Dummy test version of affwp_search_users. Modified to work in this test scenario.
 * @param        $term
 * @param string $status
 * @return array
 */
function affwp_test_search_users( $term, $status = 'none' ) {
	$search_query = htmlentities2( trim( $term ) );
	/**
	 * Fires immediately prior to an AffiliateWP user search query.
	 *
	 * @param string $search_query The user search query.
	 */
	do_action( 'affwp_pre_search_users', $search_query );
	$args = array(
			'search_columns' => array( 'user_login', 'display_name', 'user_email' ),
	);
	// Add search string to args.
	$args['search'] = '*' . mb_strtolower( $search_query ) . '*';
	// Get users matching search.
	$found_users = get_users( $args );
	$status      = isset( $status ) ? mb_strtolower( htmlentities2( trim( $status ) ) ) : 'bypass';
	$user_list   = array();
	if ( $found_users ) {
		foreach ( $found_users as $user ) {
			$label = empty( $user->user_email ) ? $user->user_login : "{$user->user_login} ({$user->user_email})";
			if ( 'bypass' !== $status ) {
				switch ( $status ) {
					case 'none':
						if ( ! affiliate_wp()->affiliates->get_by( 'user_id', $user->ID ) ) {
							$user_list[] = array(
									'label'   => $label,
									'value'   => $user->user_login,
									'user_id' => $user->ID,
							);
						}
						break;
					case 'any':
						if ( affiliate_wp()->affiliates->get_by( 'user_id', $user->ID ) ) {
							$user_list[] = array(
									'label'   => $label,
									'value'   => $user->user_login,
									'user_id' => $user->ID,
							);
						}
						break;
					default:
						$affiliate = affiliate_wp()->affiliates->get_by( 'user_id', $user->ID );
						if ( $affiliate && $status == $affiliate->status ) {
							$user_list[] = array(
									'label'   => $label,
									'value'   => $user->user_login,
									'user_id' => $user->ID,
							);
						}
				}
			} else {
				$user_list[] = array(
						'label'   => $label,
						'value'   => $user->user_login,
						'user_id' => $user->ID,
				);
			}
		}
	}

	return $user_list;
}

add_action( 'pre_user_query', function( $query ) {
	if ( ! isset( $query->query_vars['affwp_is_affiliate'] ) ) {
		return;
	}
	global $wpdb;

	if ( $query->query_vars['affwp_is_affiliate'] ) {
		$where = ' AND ID IN (SELECT user_id FROM ' . $wpdb->prefix . 'affiliate_wp_affiliates)';
	} else {
		$where = ' AND ID NOT IN (SELECT user_id FROM ' . $wpdb->prefix . 'affiliate_wp_affiliates)';
	}

	$query->query_where .= $where;
} );

get_header();
$current_method_benchmarks  = get_time_to_run_function( 'affwp_test_search_users', array( '*', 'any' ),10 );
$proposed_method_benchmarks = get_time_to_run_function( 'get_users', array(
		array(
				'affwp_is_affiliate' => true,
				'search'             => '***',
		),
),10 );
?>
<h2>Current Method</h2>
<ul>
	<?php
	foreach ( $current_method_benchmarks as $key => $benchmark ):
		?>
		<li>Benchmark <?= $key + 1 ?></li>
		<ul>
			<li>
				This completed <?= $benchmark['time'] ?> after the start
			</li>
			<li>
				Result: <?= count( $benchmark['result'] ) ?>
			</li>
		</ul>
	<?php
	endforeach;
	?>
</ul>
<h2>Proposed Method</h2>
<ul>
	<?php
	foreach ( $proposed_method_benchmarks as $key => $benchmark ):
		?>
		<li>Benchmark <?= $key + 1 ?></li>
		<ul>
			<li>
				This completed <?= $benchmark['time'] ?> after the start
			</li>
			<li>
				Result: <?= count( $benchmark['result'] ) ?>
			</li>
		</ul>
	<?php
	endforeach;
	?>
</ul>