PHP's echo function can run for more than 1 second.

Or about the features of managing content given in PHP.

The reason for this article was a two-day study, the results of which showed that the echo and print functions, innocuous in their performance, can actually work for a very long time and their performance depends on the quality of the Internet of the end user.

To begin with, if I had been told this yesterday, I would have wagged my finger at his temple with this person, but a series of tests carried out inexorably testifies to this.


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Page generation: 1 second on a powerful server and 200 ms. on the weak.

It all started with the fact that I implemented a self-written profiler in the CakePHP framework and embedded a function to calculate the execution intervals after the main logical parts of the code. On the local server, everything worked fine, the profiler showed 200-300 ms. , but on the production (the server is much more powerful, for which we have not yet caught up with the visitors), the execution time was sometimes 1-3 seconds !

Using your favorite performance debugging method:

1. $microtime = microtime(true);
2. //
3. echo (microtime(true) - $microtime);

, :

1. print $out;

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1. $index = !empty($_GET['index']) ? $_GET['index'] : 1;
2. $example_output = str_repeat(str_repeat("*", 1024), $index);
3.  
4. $microtime = microtime(true)*1000;
5. echo $example_output;
6. $interval = microtime(true)*1000 - $microtime;
7.  
8. echo '<br>Display Length: ', $index, ' KiB.<br>';
9.  
10. if($interval < 100 && $_GET['index'] < 100)
11.   echo '<meta http-equiv="refresh" content="1; url=?index='.($index + 1).'" />';
12.  
13. echo 'Reach end file: ', round($interval, 2), ' ms.'."<br>\n";

, , , echo 100 .

, 11 :

*****
Display Length: 11 KiB.
Reach end file: 0.07 ms.


12 :

*****
Display Length: 12 KiB.
Reach end file: 348.92 ms.


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wget --limit-rate=1K www.test.lo/nagle_test.php?index=128
Display Length: 128 KiB.
Reach end file: 57234.61 ms.


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