утечка памяти при обработке большого CSV

У меня есть сценарий, который загружает большой CSV-файл продукта, обрабатывает информацию в нем (загрузка изображений, изменение размера и подготовка других данных для вставки в базу данных), а затем создает еще один текстовый файл со всеми обработанными элементами. Проблема в том, что память где-то кровоточит. Я получаю сообщение об ошибке 500, но журнал показывает слишком много использования памяти. Я удалил все, что мог, и использую итераторы SPL, которые должны потреблять меньше памяти, но я все еще могу получить скрипт для завершения выполнения и ввести всю информацию. Может ли кто-нибудь указать что-то в сценарии, что помогло бы предотвратить утечку памяти?

<?php

define('IN_PHPBB', true);
define('IN_SHOP', true);
$phpbb_root_path = './../forum/';
$root_path = './../';
$phpEx = substr(strrchr(__FILE__, '.'), 1);
include($phpbb_root_path.'common.'.$phpEx);

// Start session management
$user->session_begin();
$auth->acl($user->data);
$user->setup();

set_time_limit(172800);

define('THUMBNAIL_IMAGE_MAX_WIDTH', 150);
define('THUMBNAIL_IMAGE_MAX_HEIGHT', 150);

function generate_thumb($source_image_path, $thumbnail_image_path)
{
    list($source_image_width, $source_image_height, $source_image_type) = getimagesize($source_image_path);
    switch ($source_image_type) {
        case IMAGETYPE_GIF:
            $source_gd_image = imagecreatefromgif($source_image_path);
            break;
        case IMAGETYPE_JPEG:
            $source_gd_image = imagecreatefromjpeg($source_image_path);
            break;
        case IMAGETYPE_PNG:
            $source_gd_image = imagecreatefrompng($source_image_path);
            break;
    }
    if ($source_gd_image === false) {
        return false;
    }
    $source_aspect_ratio = $source_image_width / $source_image_height;
    $thumbnail_aspect_ratio = THUMBNAIL_IMAGE_MAX_WIDTH / THUMBNAIL_IMAGE_MAX_HEIGHT;
    if ($source_image_width <= THUMBNAIL_IMAGE_MAX_WIDTH && $source_image_height <= THUMBNAIL_IMAGE_MAX_HEIGHT) {
        $thumbnail_image_width = $source_image_width;
        $thumbnail_image_height = $source_image_height;
    } elseif ($thumbnail_aspect_ratio > $source_aspect_ratio) {
        $thumbnail_image_width = (int) (THUMBNAIL_IMAGE_MAX_HEIGHT * $source_aspect_ratio);
        $thumbnail_image_height = THUMBNAIL_IMAGE_MAX_HEIGHT;
    } else {
        $thumbnail_image_width = THUMBNAIL_IMAGE_MAX_WIDTH;
        $thumbnail_image_height = (int) (THUMBNAIL_IMAGE_MAX_WIDTH / $source_aspect_ratio);
    }
    $thumbnail_gd_image = imagecreatetruecolor($thumbnail_image_width, $thumbnail_image_height);
    imagecopyresampled($thumbnail_gd_image, $source_gd_image, 0, 0, 0, 0, $thumbnail_image_width, $thumbnail_image_height, $source_image_width, $source_image_height);
    imagejpeg($thumbnail_gd_image, $thumbnail_image_path, 90);
    imagedestroy($source_gd_image);
    imagedestroy($thumbnail_gd_image);
    unset($source_image_width, $source_image_height, $source_image_type, $source_gd_image, $source_aspect_ratio, $thumbnail_aspect_ratio, $thumbnail_image_width, $thumbnail_image_height, $thumbnail_gd_image);
    return true;
}


$regex = <<<'END'
/
  (
    (?: [\x00-\x7F]               # single-byte sequences   0xxxxxxx
    |   [\xC0-\xDF][\x80-\xBF]    # double-byte sequences   110xxxxx 10xxxxxx
    |   [\xE0-\xEF][\x80-\xBF]{2} # triple-byte sequences   1110xxxx 10xxxxxx * 2
    |   [\xF0-\xF7][\x80-\xBF]{3} # quadruple-byte sequence 11110xxx 10xxxxxx * 3 
    )+                            # ...one or more times
  )
| ( [\x80-\xBF] )                 # invalid byte in range 10000000 - 10111111
| ( [\xC0-\xFF] )                 # invalid byte in range 11000000 - 11111111
/x
END;
function utf8replacer($captures) {
  if ($captures[1] != "") {
    // Valid byte sequence. Return unmodified.
    return $captures[1];
  }
  elseif ($captures[2] != "") {
    // Invalid byte of the form 10xxxxxx.
    // Encode as 11000010 10xxxxxx.
    return "\xC2".$captures[2];
  }
  else {
    // Invalid byte of the form 11xxxxxx.
    // Encode as 11000011 10xxxxxx.
    return "\xC3".chr(ord($captures[3])-64);
  }
}

/* download file from source */
function getDataCSV(){
    $thefile = 'http://feeds.cnv.com/xxxxxxxxxxxxxx/Bronze/ELD-B01.csv';
    $file = 'ELD-B01.csv';

    $fh = fopen($file, "w");
    $rows = file($thefile);
    foreach($rows as $num => $row){
        if($num != 0){
            fwrite($fh, $row);
        }
    }
    fclose($fh);

    include("DataSource.php");

    $csv = new File_CSV_DataSource;
    if ($csv->load($file)) {
        $items = $csv->getHeaders();
        $csv->getColumn($items[2]);
        if ($csv->isSymmetric()) {
            $items = $csv->connect();
        } else {
            $items = $csv->getAsymmetricRows();
        }
        $items = $csv->getrawArray();
    }
    unset($csv);
    return $items;
}

$iter = new ArrayIterator(getDataCSV());

$google_list = array();
$google_list[] = array('id', 'title', 'description', 'google_product_category', 'product_type', 'link', 'image_link', 'condition', 'availability', 'price', 'brand', 'mpn');

$sql = "TRUNCATE TABLE ".SHOP_ITEMS;
$db->sql_query($sql);

foreach($iter as $item){
    if($item[12] != ""){
        $catName = str_replace(" ", "-", str_replace("and ", "", str_replace(",", "", str_replace("&amp;", "and", str_replace("-", "", $item[12])))));
    }else{
        $catName = str_replace(" ", "-", str_replace("and ", "", str_replace(",", "", str_replace("&amp;", "and", str_replace("-", "", $item[11])))));
    }

    $sql = 'SELECT cat_id FROM '.SHOP_CATS.' WHERE cat_clean = "'.$catName.'"';
    $result = $db->sql_query($sql);
    $row = $db->sql_fetchrow($result);
    $db->sql_freeresult($result);
    $catId = $row['cat_id'];

    $img = $item[9];
    $ext = substr($img, strrpos($img, '.') + 1);
    $image = 'images/products/'.$item[0].'.'.$ext;
    file_put_contents($root_path.$image, file_get_contents($img));
    $thumb = "images/products/thumbs/".$item[0]."_thumb.".$ext;

    generate_thumb($root_path.$image, $thumb);

    $itmRow = array(
        'item_name' => str_replace("/", "", preg_replace_callback($regex, "utf8replacer", html_entity_decode(html_entity_decode($item[1], ENT_QUOTES)))),
        'item_price' => $item[2],
        'item_description' => preg_replace_callback($regex, "utf8replacer", html_entity_decode(html_entity_decode($item[4], ENT_QUOTES))),
        'item_model' => $item[0],
        'item_manufacturer' => ($item[6] == '') ? 'No Info' : $item[6],
        'item_image' => $image,
        'item_cat' => ($catId) ? $catId : 0,
        'item_number' => $item[0],
        'item_vendor_code' => "ELD",
        'item_stock' => (strtolower($item[5]) == 'in stock') ? 1 : 0,
        'item_added' => strtotime($item[8]),
        'item_upc' => ($item[13] == '') ? 'No Info' : $item[13],
        'item_url' => '',
        'item_weight' => ($item[14] == '') ? 'No Info' : $item[14],
    );

    $sql = 'INSERT INTO '.SHOP_ITEMS.' '.$db->sql_build_array('INSERT', $itmRow);
    $db->sql_query($sql);
    $itmId = $db->sql_nextid();

    if(strstr($itmRow['item_name'], "-") == FALSE){
        $seo = urlencode(str_replace(" ", "-", $itmRow['item_name'])).".html";
    }else{
        $seo = urlencode(str_replace(" ", "_", $itmRow['item_name'])).".html";
    }
    if($item[5] == "oos"){
        $stock = "Out of Stock";
    }else{
        $stock = "In Stock";
    }
    $u_product = "https://therealmsofwickedry.com/product/".$seo;

    $google_list[] = array($itmId, $itmRow['item_name'], $itmRow['item_description'], 'Mature > Erotic', $catName, $u_product, "https://therealmsofwickedry.com/".$itmRow['item_image'], "new", $stock, $itmRow['item_price'], $itmRow['item_manufacturer'], $itmRow['item_model']);
    unset($catName, $catId, $img, $ext, $image, $thumb, $itmRow, $itmId, $seo, $stock, $u_product);
}

$line = '';

foreach($google_list as $list){
    $line .= implode("\t", $list);
    $line .= "\n";
}

$google = 'google_products.txt';
$h = fopen($google, "w");
fwrite($h, $line);
fclose($h);

?>