Memory leak when setting nested keys using dot notation

[raducorcan]

• Laravel-mongodb Version: 4.3.0
• PHP Version: 8.3
• Database Driver & Version: 1.15.0 & 5.0

Description:

There appears to be a memory leak when setting nested keys using dot notation. I am attaching a very simple code snippet that exemplifies the issue.

Steps to reproduce

class A extends \MongoDB\Laravel\Eloquent\Model {};

$a = new A;
for ($i = 0; $i < 100; $i++) {
  $a['somerandomkey'] = 42;
  echo (memory_get_usage() / (1024*1024) . "\n"); // this prints the same value in every iteration
}

//----------------------------------

class A extends \MongoDB\Laravel\Eloquent\Model {};

$a = new A;
for ($i = 0; $i < 100; $i++) {
  $a['some.random.key'] = 42;
  echo (memory_get_usage() / (1024*1024) . "\n"); // this prints increasingly larger values
}

Expected behaviour

Script memory usage keeps increasing.

Actual behaviour

The memory usage should remain constant.

[GromNaN]

Thanks for the report. I can confirm this is specific to the MongoDB package as there is no memory leak by extending Illuminate\Database\Eloquent\Model.

Tracking in Jira for investigation: PHPORM-184

[GromNaN]

There is a hack in Model::setAttribute that uses a temporary key and then remove it. I suspect the memory leak to come from here.

laravel-mongodb/src/Eloquent/Model.php

Lines 272 to 282 in b892bb0

	if (str_contains($key, '.')) {
	// Store to a temporary key, then move data to the actual key
	$uniqueKey = uniqid($key);
	parent::setAttribute($uniqueKey, $value);
	Arr::set($this->attributes, $key, $this->attributes[$uniqueKey] ?? null);
	unset($this->attributes[$uniqueKey]);
	return $this;
	}

[GromNaN]

Fixed by #2962