Obtain the memory usage of php code_PHP tutorial-PHP Tutorial-php.cn

Obtain the memory usage of php code_PHP tutorial

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Release： 2016-07-13 16:57:33

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To get the memory usage of php scripts in php, we can use php's own function memory_get_usage() as an example. It can check the memory occupied by the current PHP script execution. Let me take a look below.

memory_get_usage( )Official Grammar

1. Function prototype
int memory_get_usage ([ bool $real_usage = false ] )

Two, version compatible
PHP 4 >= 4.3.2, PHP 5

3. Basic usage and examples

We can directly use the PHP function memory_get_usage() to check how much memory the system has allocated to the current PHP script execution.

The code is as follows

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代码如下	复制代码
echo memory_get_usage(), ' '; // 79248 $tmp = str_repeat('http://3aj.cn/', 4000); // 135408 echo memory_get_usage(), ' '; unset($tmp); echo memory_get_usage(); // 79248 ?>

echo memory_get_usage(), '
'; // 79248

$tmp = str_repeat('http://3aj.cn/', 4000); // 135408

echo memory_get_usage(), '
';

unset($tmp);

echo memory_get_usage(); // 79248

The numerical unit output by the program is byte(s), which is the memory used by the PHP script at that time (excluding the memory occupied by the memory_get_usage() function itself).

代码如下

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function convert($size){

$unit=array('b','kb','mb','gb','tb','pb');

return @round($size/pow(1024,($i=floor(log($size,1024)))),2).' '.$unit[$i];

}

echo convert(memory_get_usage(true));

As can be seen from the above example, in order to reduce memory usage, you can use the PHP unset() function to delete variables that are no longer needed. Similar ones include: PHP mysql_free_result() function, which can clear the result set obtained by querying the database that is no longer needed, so that more available memory can be obtained.

PHP memory_get_usage() function can also have a parameter, $real_usage, whose value is a Boolean value. The default is FALSE, which means that the obtained memory usage does not include the memory occupied by this function (PHP memory manager); when set to TRUE, the obtained memory does not include the memory occupied by this function (PHP memory manager).

Format memory_get_usage() result output in KB units

代码如下	复制代码
function array_size($arr){ ob_start(); print_r($arr); $mem=ob_get_contents(); ob_end_clean(); $mem=preg_replace("/n +/","",$mem); $mem=strlen($mem); return $mem; } $memEstimate=array_size($GLOBALS); ?>

The code is as follows	Copy code
<🎜> function convert($size){ <🎜> <🎜> $unit=array('b','kb','mb','gb','tb','pb'); <🎜> <🎜> return @round($size/pow(1024,($i=floor(log($size,1024)))),2).' '.$unit[$i]; <🎜> <🎜> } <🎜> <🎜>echo convert(memory_get_usage(true)); <🎜> <🎜> ?>

Custom function to get the size of array or variable value

The code is as follows	Copy code
function array_size($arr){<🎜> ob_start();<🎜> print_r($arr);<🎜> $mem=ob_get_contents();<🎜> ob_end_clean();<🎜> $mem=preg_replace("/n +/","",$mem);<🎜> $mem=strlen($mem);<🎜> return $mem;<🎜> } <🎜> $memEstimate=array_size($GLOBALS);<🎜> ?>

So in actual programming, you can use the memory_get_usage() function to compare the memory occupied by each method to choose which method takes up less memory.

Comes with a usage function:

exec("ps -eo%mem,rss,pid | grep $pid", $output); $output = explode(" ", $output[0]);

The code is as follows

代码如下	复制代码
if (!function_exists('memory_get_usage')) { function memory_get_usage() { $pid = getmypid(); if (IS_WIN) { exec('tasklist /FI "PID eq ' . $pid . '" /FO LIST', $output); return preg_replace('/[^0-9]/', '', $output[5]) * 1024; } else { exec("ps -eo%mem,rss,pid \| grep $pid", $output); $output = explode(" ", $output[0]); return $output[1] * 1024; } } } ?>

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function memory_get_usage() {

$pid = getmypid();

代码如下

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//memory_get_usage();

$m1 = memory_get_usage();
echo '
m1:',$m1; // m1:80160

$a = 'hello';
$b = str_repeat($a,1000);

$m2 = memory_get_usage();
echo '
m2:',$m2; // m2:85624

unset($b);

$m3 = memory_get_usage();
echo '
m3:',$m3; // m3:80600
?>

If (IS_WIN) {

exec('tasklist /FI "PID eq ' . $pid . '" /FO LIST', $output);
return preg_replace('/[^0-9]/', '', $output[5]) * 1024;

} else {

return $output[1] * 1024; }

}