1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2014 - 2015, British Columbia Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
* @copyright Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
* @license http://opensource.org/licenses/MIT MIT License
* @link http://codeigniter.com
* @since Version 1.0.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');

/**
* Benchmark Class
*
* This class enables you to mark points and calculate the time difference
* between them. Memory consumption can also be displayed.
*
* @package CodeIgniter
* @subpackage Libraries
* @category Libraries
* @author EllisLab Dev Team
* @link http://codeigniter.com/user_guide/libraries/benchmark.html
*/
class CI_Benchmark {

/**
* List of all benchmark markers
*
* @var array
*/
public $marker = array();

/**
* Set a benchmark marker
*
* Multiple calls to this function can be made so that several
* execution points can be timed.
* 记录时间点。
*
* @param string $name Marker name
* @return void
*/
public function mark($name)
{
$this->marker[$name] = microtime(TRUE);
}

函数:mixed microtime ([ bool $get_as_float ] ) 本函数以 “msec sec” 的格式返回一个字符串,其中 sec 是自 Unix 纪元(0:00:00 January 1, 1970 GMT)起到现在的秒数,msec 是微秒部分。字符串的两部分都是以秒为单位返回的。
如果给出了 get_as_float 参数并且其值等价于 TRUE,microtime() 将返回一个浮点数。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
// --------------------------------------------------------------------

/**
* Elapsed time
*
* Calculates the time difference between two marked points.
*
* If the first parameter is empty this function instead returns the
* {elapsed_time} pseudo-variable. This permits the full system
* execution time to be shown in a template. The output class will
* swap the real value for this variable.
* 计算两点间的消耗时间
*
* @param string $point1 A particular marked point
* @param string $point2 A particular marked point
* @param int $decimals Number of decimal places
*
* @return string Calculated elapsed time on success,
* an '{elapsed_string}' if $point1 is empty
* or an empty string if $point1 is not found.
*/
public function elapsed_time($point1 = '', $point2 = '', $decimals = 4)
{
if ($point1 === '')
{
return '{elapsed_time}';
}

if ( ! isset($this->marker[$point1]))
{
return '';
}

if ( ! isset($this->marker[$point2]))
{
$this->marker[$point2] = microtime(TRUE);
}

return number_format($this->marker[$point2] - $this->marker[$point1], $decimals);
}

函数:string number_format ( float $number [, int $decimals = 0 ] )
本函数可以接受1个、2个或者4个参数(注意:不能是3个):

如果只提供第一个参数,number的小数部分会被去掉 并且每个千位分隔符都是英文小写逗号”,”

如果提供两个参数,number将保留小数点后的位数到你设定的值,其余同楼上

如果提供了四个参数,number 将保留decimals个长度的小数部分,
小数点被替换为dec_point,千位分隔符替换为thousands_sep

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
	// --------------------------------------------------------------------

/**
* Memory Usage
*
* Simply returns the {memory_usage} marker.
*
* This permits it to be put it anywhere in a template
* without the memory being calculated until the end.
* The output class will swap the real value for this variable.
*
* @return string '{memory_usage}'
*/
public function memory_usage()
{
return '{memory_usage}';
}

}