benchmark of some loops in php

benchmark_loops.php

<?php

$a = function($array) {
    $ret = [];
    foreach($array as $item)
    {
        $ret[] = $item;
    }
    
    return $ret;
};


$b = function($array) {
    
    $ret = [];
    foreach($array as $key => $item)
    {
        $ret[] = $item;
    }
    
    return $ret;
};

$c = function($array) {
    
    /**
     * Note: The end of an array is indistinguishable from a boolean FALSE element.
     * To properly traverse an array which may contain FALSE elements, see the foreach() function.
     * To still use next() and properly check if the end of the array has been reached,
     * verify that the key() is NULL.
     */
    
    $ret = [];
    while(!is_null(key($array))) {
        
        $ret[] = current($array);next($array);
    }
    
    return $ret;
};


$d = function($array) {
    
    $ret = [];
    for($a=0;$a<count($array);$a++) {
        $ret[] = $array[$a];
    };
    
    return $ret;
};

$e = function($array) {
    $ret = [];
    $count = count($array);
    for($a=0;$a<$count;$a++) {
        $ret[] = $array[$a];
    };
    
    return $ret;
};

$f = function($array) {
    $ret = [];
    $count = sizeof($array);
    for($a=0;$a<$count;$a++) {
        $ret[] = $array[$a];
    };
    
    return $ret;
};

$argArrayKeyValue = [];
$argArrayWithArrayValue = [];
$argArrayWithArrayKeyValue = [];

for($x = 0; $x < 1000; $x++)
{
    $argArrayKeyValue[$x] = $x;
    $argArrayWithArrayValue[$x] = [$x];
    $argArrayWithArrayKeyValue[$x] = [$x => $x];
}

$tests = [
    'Test with Array simple : $a[$x] = $x' => $argArrayKeyValue,
    'Test with Array simple : $a[$x] = [$x]' => $argArrayWithArrayValue,
    'Test with Array simple : $a[$x] = [$x => $x]' => $argArrayWithArrayKeyValue,
];

foreach($tests as $title => $array)
{
    echo '<h1>' . $title . '</h1>';
    
    $bm = new benchmark();
    
    $bm->_sample_output   = 0;
    $bm->show_differences = 1; // it will check the return value if is the same throw cycles
    
    $bm->time_this('foreach:$val', $a, [$array]);
    $bm->time_this('foreach:$key=>$val', $b, [$array]);
    $bm->time_this('do...while+next', $c, [$array]);
    $bm->time_this('for+count_in', $d, [$array]);
    $bm->time_this('for+count_out', $e, [$array]);
    $bm->time_this('for+sizeof_out', $f, [$array]);
    
    $bm->html_summary();
}


// https://github.com/scottchiefbaker/php-benchmark

class benchmark {
    public $_sample_output = 0; //  sample out in HTML summary
    public $show_differences      = 0; // Highlight if one test has diferent output than the others
    public $test_seconds          = 1; // Time to run each test
    
    private $results = array(); // Array that will store the results
    
    public function time_this($name, $func, $args = array()) {
        $seconds = $this->test_seconds;
        $count   = 0;
        $start   = microtime(1);
        $time    = 0;
        
        while ($time < $seconds) {
            $ret = call_user_func_array($func,$args);
            
            $time = microtime(1) - $start;
            $count++;
        }
        
        $this->results['count'][$name]  = intval($count / $seconds);
        $this->results['return'][$name] = $ret;
    }
    
    public function summary($type = "") {
        if ($type != "html" && php_sapi_name() === 'cli') {
            $this->text_summary();
        } else {
            $this->html_summary();
        }
    }
    
    public function text_summary() {
        if (sizeof($this->results['count']) === 0) {
            print "No results found";
            return false;
        }
        
        $use_color = 1;
        
        if ($use_color) {
            $red    = "\033[38;5;9m";
            $white  = "\033[38;5;15m";
            $blue   = "\033[38;5;51m";
            $yellow = "\033[38;5;227m";
            $reset  = "\033[0m";
        } else {
            $red    = "";
            $white  = "";
            $blue   = "";
            $yellow = "";
            $reset  = "";
        }
        
        $php_version = phpversion();
        print $white . "PHP Version: $blue$php_version$reset\n\n";
        
        arsort($this->results['count']);
        
        $test_names = array_keys($this->results['count']);
        
        $max_len   = 0;
        $total_len = 0;
        foreach ($test_names as $name) {
            // Minimum allowed length for alignment is 8 in text mode
            $len = strlen($name);
            if ($len < 8) {
                $len = 8;
            }
            
            $total_len += $len;
            if (strlen($name) > $max_len) {
                $max_len = strlen($name);
            }
        }
        
        ##############################################
        
        print str_repeat(" ",$max_len + 4); // Indent
        
        $pad_names = $test_names;
        foreach ($pad_names as &$i) {
            $i = sprintf("$yellow%8s$reset",$i);
        }
        print join(" | ",$pad_names) . "\n";
        
        // The length of the bar is the total length of the test names,
        // plus the " | " between each word test pair,
        // plus four because there are two spaces at the start and end
        $additional = (sizeof($test_names) - 1) * 3;
        $bar = str_repeat(" ",$max_len + 2) . "+" . str_repeat("-",$total_len + $additional + 2) . "+\n";
        print $bar;
        
        foreach($test_names as $y_name) {
            printf(" $yellow%{$max_len}s$reset |",$y_name);
            foreach ($test_names as $x_name) {
                $x_val     = $this->results['count'][$x_name];
                $y_val     = $this->results['count'][$y_name];
                $percent   = round(($y_val / $x_val) * 100,2) . "%";
                
                $x_name = sprintf("%8s",$x_name);
                $col_width = strlen($x_name) + 1;
                
                if ($y_val === $x_val) {
                    $percent = "N/A";
                    printf("$red%{$col_width}s$reset |",$percent);
                } else {
                    printf("$white%{$col_width}s$reset |",$percent);
                }
            }
            
            print "\n";
        }
        print $bar;
        
        print "\n";
        $max_len += 1;
        
        $expected_results = reset($this->results['return']);
        
        //print_r($this->results['count']);
        foreach($test_names as $name) {
            $count = $this->results['count'][$name];
            $ret   = $this->results['return'][$name];
            
            if ($this->_sample_output) {
                printf(" %s = %s iterations per second\n",$name,number_format($count));
                
                if ($this->show_differences && ($ret !== $expected_results)) {
                    print "    ** Return value from this function differs from the first test **\n";
                }
                
                $print_r_output = trim(print_r($ret,true));
                
                $print_r_output = preg_replace("/^/m","       ",$print_r_output);
                
                print "    Sample output: \n$print_r_output\n\n";
            } else {
                printf("%{$max_len}s = %s iterations per second\n",$name,number_format($count));
            }
        }
        
        print "\n";
    }
    
    public function html_summary() {
        if (sizeof($this->results['count']) === 0) {
            print "<div>No results found</div>";
            return false;
        }
        
        arsort($this->results['count']);
        
        $tests = array_keys($this->results['count']);
        array_unshift($tests,' ');
        $first = 1;
        
        $php_version = phpversion();
        $out = "<h2>PHP Version: $php_version</h2>";
        
        $header_color = '#CCE6FF';
        $out .= '<table style="border-collapse: collapse; border: 1px solid black; width: 100%;">';
        $x = 0;
        foreach ($tests as $name) {
            $out .= "<tr>";
            
            // If it's the first row, output all the headers
            if ($first) {
                foreach ($tests as $i) {
                    $out .= '<td style="padding: 5px; white-space: nowrap; text-align: center; font-weight: bold; background-color: '.$header_color.'; border: 1px solid black; width: 10em;">'.$i.'</td>';
                }
                
                $first = 0;
                // It's not the first row so loop through outputting each data cell
            } else {
                $column = 0;
                $y = 0;
                foreach ($tests as $i) {
                    // If it's the first column, it's the row header (on the left)
                    if ($column == 0) {
                        $content = $tests[$x + 1];
                        $color   = $header_color;
                        $align   = 'right';
                        $fw      = 'bold';
                        $x++;
                    } else {
                        $y++;
                        
                        $x_name = $tests[$x];
                        $y_name = $tests[$y];
                        
                        $a = $this->results['count'][$x_name];
                        $b = $this->results['count'][$y_name];
                        
                        $percentage = sprintf("%.2f%%",($a / $b) * 100);
                        
                        $color = 'white';
                        $align = 'center';
                        $fw    = 'normal';
                        
                        // Row/Column are the same so we output n/a
                        if ($x === $y) {
                            $color   = "#FF9999";
                            $content = "<b>n/a</b>";
                            // It's a legit data point
                        } else {
                            $content = "$percentage";
                        }
                    }
                    
                    // Output each data cell
                    $out .= '<td style="padding: 5px; white-space: nowrap; background-color: '.$color.'; font-weight: '.$fw.'; text-align: '.$align.'; border: 1px solid black; width: 10em;">'.$content.'</td>';
                    
                    $column++;
                }
            }
            $out .= "</tr>";
        }
        $out .= "</table>";
        $out .= "<br />";
        
        $slowest = min($this->results['count']);
        $fastest = max($this->results['count']);
        
        $expected_results = reset($this->results['return']);
        
        $out .= "<table>";
        foreach ($this->results['count'] as $test => $speed) {
            $ret = $this->results['return'][$test];
            
            $speed_str = number_format($speed);
            $out .= '<tr><td style="padding: 1px 3px; text-align: right;"><b>'.$test.':</b></td><td style="padding: 0 3px;">'.$speed_str.' iterations per second';
            
            if ($this->show_differences && ($ret !== $expected_results)) {
                $out .= '<div style="margin: 0 0 1em 2em; "><span style="color: red;"><b>!!!</b></span> Return value from this function differs from the first test</div>';
            }
            
            if ($this->_sample_output) {
                $out .= '<div style="margin: 0 0 1em 2em; "><b>Sample output:</b> ' . print_r($ret,true) . '</div>';
            }
            
            $out .= "</td></tr>";
        }
        $out .= "</table>";
        
        print $out;
    }
    
    public function reset() {
        $this->results = array();
    }
    
} // End of class