lazysessionstart.php

<?php
 
namespace Bitrix\Main\Session\Legacy;
 
use Bitrix\Main\Application;
use Bitrix\Main\InvalidOperationException;
 
final class LazySessionStart implements \ArrayAccess
{
    private static $instance;
 
    public static function register(): void
    {
        if (self::$instance)
        {
            throw new InvalidOperationException("LazySessionStart was already registered.");
        }
 
        // It's very important to make a reference to the LazySessionStart object,
        // because when somebody uses $_SESSION['d'] += $value;
        // it converts to: offsetGet & offsetSet. But PHP destroys
        // the object because it'll be the last reference and offsetSet crashes.
        $_SESSION = self::$instance = new self();
    }
 
    protected function start(): void
    {
        if ($this->isSessionAlreadyClosed() && !Application::getInstance()->getSession()->isAccessible())
        {
            $this->writeToLogError(
                new \RuntimeException(
                    "Skipped cold session start because headers have already been sent. Be aware and fix usage of session, details in trace."
                )
            );
 
            $GLOBALS['_SESSION'] = [];
 
            return;
        }
 
        Application::getInstance()->getSession()->start();
    }
 
    public function offsetExists($offset): bool
    {
        $this->start();
 
        return isset($_SESSION[$offset]);
    }
 
    #[\ReturnTypeWillChange]
    public function &offsetGet($offset)
    {
        $this->start();
 
        return $_SESSION[$offset];
    }
 
    public function offsetSet($offset, $value): void
    {
        $this->start();
 
        $_SESSION[$offset] = $value;
    }
 
    public function offsetUnset($offset): void
    {
        $this->start();
 
        unset($_SESSION[$offset]);
    }
 
    private function isKernelWentSessionStart(): bool
    {
        return defined('BX_STARTED');
    }
 
    private function isSessionAlreadyClosed(): bool
    {
        return
            $this->isKernelWentSessionStart()
            && !Application::getInstance()->getKernelSession()->isStarted()
        ;
    }
 
    private function writeToLogError(\RuntimeException $exception): void
    {
        $exceptionHandler = Application::getInstance()->getExceptionHandler();
        $exceptionHandler->writeToLog($exception);
    }
}