[BUG]: Phalcon\Support classes leak memory round 2

[maxgalbu]

ref: #16571

Describe the bug Instantiating and invoking a Phalcon/Support class many times make memory grow too much. I'm using it in a forever-running CLI script.

To Reproduce

Script to reproduce the behavior:

<?php
use Phalcon\Support\HelperFactory;

echo "beginning: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";

$helper = new HelperFactory();
foreach (range(1,100000) as $num) {
    $helper->camelize("transaction_id");
}

echo "end: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";

Output:

beginning: 0.40937042236328
end: 42.000595092773

Expected behavior Memory should not increase so much. Same camelized output using userland HelperFactory that uses ucwords():

Expand to see code

<?php

echo "beginning: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";

class Camelize
{
    public function __invoke(
        string $text,
        string $delimiters = "",
        bool $lowerFirst = false
    ): string {
        return str_replace(str_split($delimiters), "", ucwords($text));
    }
}

class HelperFactory
{
    private array $services = [];

    public function __call(string $name, array $arguments)
    {
        $helper = $this->newInstance($name);
        return call_user_func_array([$helper, "__invoke"], $arguments);
    }

    public function newInstance(string $name)
    {
        if (!isset($this->services[$name])) {
            $this->services[$name] = new ($this->getServices($name));
        }

        return $this->services[$name];
    }

    protected function getServices($name)
    {
        return [
            "camelize"      => "Camelize",
        ][$name];
    }
}

$helper = new HelperFactory();
foreach (range(1,100000) as $num) {
    $helper->camelize("transaction_id");
}

echo "end: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";

beginning: 0.41297149658203
end: 4.3821716308594

Details

Phalcon version: 5.7.0
PHP Version: 8.1.27
Operating System: Debian
Installation type: installing via package manager
Zephir version (if any):
Server: N/A (cli script)

[apoca]

This issue is a very serious matter, we have schedulers taking 40 minutes longer than before. We downgraded to version 5.3.1 and it's super fast... We also tried 5.6.1 and it has the same problem. We are currently reverting all of our sites to version 5.3.1

@niden I think this is very serious...

[noone-silent]

I could detect the cause for the memory leak in camelize but ucwords I did not have any memory increase at all.

// Run with 100.000 iterations
root@cphalcon-83:/srv# php -d"extension=phalcon.so" ./.local/helper-test.php
beginning: 0.40730285644531
end: 2.3891067504883

// Run with 1.000.000 iterations
root@cphalcon-83:/srv# php -d"extension=phalcon.so" ./.local/helper-test.php
beginning: 0.40730285644531
end: 16.389106750488

[apoca]

Well, guys... It seen to be the PHP version, we've changed the PHP version and it was fast again.. Not sure if is Phalcon version... I'll put here more information.

Anyway, @noone-silent what is your PHP version?

[noone-silent]

Well, guys... It seen to be the PHP version, we've changed the PHP version and it was fast again.. Not sure if is Phalcon version... I'll put here more information.

Anyway, @noone-silent what is your PHP version?

I came on it, because of this php bug https://bugs.php.net/bug.php?id=76982 They introduced some bugs with closures and anonymous functions. I think they mentioned it started with php 8.1

[maxgalbu]

This issue is a very serious matter, we have schedulers taking 40 minutes longer than before. We downgraded to version 5.3.1 and it's super fast... We also tried 5.6.1 and it has the same problem. We are currently reverting all of our sites to version 5.3.1

@apoca I don't think this is either fast or slow, it's a memory leak... the issue was present in 5.0.0 all the way up to 5.7.0. Anyway, what were the php versions you used before and after?

I could detect the cause for the memory leak in camelize but ucwords I did not have any memory increase at all.

@noone-silent Is this the same as what I wrote in the issue description (camelize in phalcon VS ucwords in userland code), or are you talking about something else?

They introduced some bugs with closures and anonymous functions. I think they mentioned it started with php 8.1

@noone-silent It's weird that your commit fixes the bug... so every part of phalcon that uses array_map() or any other function that uses anonymous functions is leaking? 🤯

[noone-silent]

I could detect the cause for the memory leak in camelize but ucwords I did not have any memory increase at all.

@noone-silent Is this the same as what I wrote in the issue description (camelize in phalcon VS ucwords in userland code), or are you talking about something else?

Maybe I understood you wrong. I understood you, that camelize and ucwords in Phalcon have the same memory leak. So I checked camelize and ucwords, but could only find the bug in camelize.

They introduced some bugs with closures and anonymous functions. I think they mentioned it started with php 8.1

@noone-silent It's weird that your commit fixes the bug... so every part of phalcon that uses array_map() or any other function that uses anonymous functions is leaking? 🤯

It looks like that.

[maxgalbu]

Maybe I understood you wrong. I understood you, that camelize and ucwords in Phalcon have the same memory leak. So I checked camelize and ucwords, but could only find the bug in camelize.

Not at all, my example with ucwords() was to show that camelize() leaks a lot:

Camelize with Phalcon HelperFactory has this memory impact:

beginning: 0.40937042236328
end: 42.000595092773

Same output (not memory, output, eg echo "somethingCamelized") using userland HelperFactory that uses ucwords() has this memory impact:

beginning: 0.41297149658203
end: 4.3821716308594

[apoca]

Well, we just tested something else the php cli is much slower in versions of PHP 8.1.26 or higher with Phalcon 5.3.1 or higher.

@maxgalbu could you test with PHP version 8.1.23?

[kenyeung826]

<?php

use Phalcon\Support\Helper\Str\PascalCase as PhPascalCase;

class PascalCase {

   public function __invoke(
        $text,
        $delimiters = null
    ) {

        $exploded = $this->processArray($text, $delimiters);

        $output = array_map(
            function ($element) {
                return ucfirst(mb_strtolower($element));
            },
            $exploded
        );

        return implode("", $output);
        }

        protected function processArray($text, $delimiters = null)
    {

        if ($delimiters === null) {
            $delimiters = "-_";
        }

        /**
         * Escape the `-` if it exists so that it does not get interpreted
         * as a range. First remove any escaping for the `-` if present and then
         * add it again - just to be on the safe side
         */
        if (strpos($delimiters, "\\-") !== false || strpos($delimiters, "-") !== false) {
            $delimiters = str_replace(["\\-", "-"], ["", ""], $delimiters);
            $delimiters = "-" .$delimiters;
        }

        $result = preg_split(
            "/[" . $delimiters . "]+/",
            $text,
            -1,
            PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY
        );

        return (false === $result) ? [] : $result;
    }
}

echo "beginning: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";
foreach (range(1,100000) as $num) {
    $helper = (new PascalCase)("transaction_id");
}
echo "end: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";
memory_reset_peak_usage();

echo "beginning: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";
foreach (range(1,100000) as $num) {
    $helper = (new PhPascalCase)("transaction_id");
}

echo "end: ".memory_get_peak_usage() / 1024 / 1024;
echo "\n";

some insight (phalcon-5.6.2, php8.3) I have copy the code from cphalcon/phalcon/Support/Helper/Str/PascalCase.zep and run the result

beginning: 0.8388671875 end: 2.8052978515625

beginning: 0.79993438720703 end: 40.419456481934

[noone-silent]

There is already a fix coming. Try your code with the following changes and it should work:

Replace:

$output = array_map(
    function ($element) {
        return ucfirst(mb_strtolower($element));
    },
    $exploded
);

return implode("", $output);

With

$output = '';
foreach ($exploded as $element) {
    $output .=  ucfirst(mb_strtolower($element));
}

return $output;