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我正在运行两个几乎相同的程序，除了一个只需要查看最低价格，第二个需要查看最低 4 个价格并获得平均值。我的问题是，在运行第二个程序时，出现内存不足的 php 致命错误。我的托管服务提供商已为我设置了 3000M 的内存限制，但我仍然收到错误消息。这是第一个程序的代码：

    $parsed_xml = amazon_xml($isbn);

$current = $parsed_xml->ListMatchingProductsResult->Products->Product;
$asin = $current->Identifiers->MarketplaceASIN->ASIN;
//print_r($asin);

// get information based on the items ASIN
$price_xml = amazonPrice_xml($asin, $ItemCondition);
$currentPrice = $price_xml ->GetLowestOfferListingsForASINResult->Product->LowestOfferListings->LowestOfferListing;
$listPrice = $currentPrice->Price->ListingPrice->Amount;

// check to see if there are values
if(!empty($listPrice))
{  
            //print_r($listPrice); die;
//if($currentPrice->Price->ListingPrice->Amount > 0) {
    while(count($lowestPrices) < 2)
    {

            foreach($currentPrice as $offer){ 
                $totalFeedback = $offer->SellerFeedbackCount;

                $condition = $offer->Qualifiers->ItemSubcondition;

                //amazon condition matching algorithm (so we can match our condition up against amazons conditions)
                switch ($condition) {
                case "New":
                    $amazonCondition = 5;
                    break;
                case "Mint":
                    $amazonCondition = 4;
                    break;
                case "VeryGood":
                    $amazonCondition = 3;
                    break;
                case "Good":
                    $amazonCondition = 2;
                    break;
                case "Acceptable":
                    $amazonCondition = 1;
                    break;
                default:
                    $amazonCondition = 0;
                } // end of switch statement

            //echo $condition . "|" . $ourCondition . "|" . $amazonCondition . "|" . count($lowestPrices) . "|" . $totalFeedback . "|" . $merchantId . "<br/>";

            /* default lowest 1 */
                if(count($lowestPricesDefault[$a] <2)){
                $lowestPricesDefault[$a] = str_replace('$','',$offer->Price->ListingPrice->Amount);
                $a++;
                }

                if( ($ourCondition <= $amazonCondition) && ($totalFeedback >= 1500) &&  (count($lowestPrices) <2) )
                {
                $lowestPrices[$x] = str_replace('$','',$offer->Price->ListingPrice->Amount);
                $x++;
                }

            }
        $z++;
    }


    if(count($lowestPrices) > 0){
        $avgPrice = (array_sum($lowestPrices)/count($lowestPrices)) - .10;
        $source = "Amazon Condition Price";
    }else{
        //$avgPrice = $listPrice - ($listPrice * 0.25);
        $avgPrice = (array_sum($lowestPricesDefault)/count($lowestPricesDefault)) - .10;
        $source = "Default Pricing";
    }

    //make sure avg price is atleast 5.50, >236% of follett price, and >=200% of our cost
    if($avgPrice < ($follettPrice * 2.37)){
        $avgPrice = $follettPrice * 2.37;
        $source = "Follett Pricing";
    }
    if($avgPrice < ($row['cost'] * 2)){
        $avgPrice = $row['cost'] * 2;
        $source = "Double Cost";
    }
    if($avgPrice < 5.50){
        $avgPrice = 5.50;
        $source = "Lowest Base Cost";
    }

    //update Prices
    $conn->query("UPDATE inventory SET ourPrice = $avgPrice WHERE sku=" . $row['sku']);

这是第二个程序：

    $parsed_xml = amazon_xml($isbn);

$current = $parsed_xml->ListMatchingProductsResult->Products->Product;
$asin = $current->Identifiers->MarketplaceASIN->ASIN;

// get information based on the items ASIN
$price_xml = amazonPrice_xml($asin, $ItemCondition);
$currentPrice = $price_xml ->GetLowestOfferListingsForASINResult->Product->LowestOfferListings->LowestOfferListing;
$listPrice = $currentPrice->Price->ListingPrice->Amount;

// check to see if there are values
if(!empty($listPrice))
{  
//if($price_xml) {
    while(count($lowestPrices) < 4 ) // changed count to 4 per loralee's email 5-1-2012
    {


        foreach($currentPrice as $offer){
            $totalFeedback = $offer->SellerFeedbackCount;

            $condition = $offer->Qualifiers->ItemSubcondition;

                //amazon condition matching algorithm (so we can match our condition up against amazons conditions)
                switch ($condition) {
                case "New":
                    $amazonCondition = 5;
                    break;
                case "Mint":
                    $amazonCondition = 4;
                    break;
                case "VeryGood":
                    $amazonCondition = 3;
                    break;
                case "Good":
                    $amazonCondition = 2;
                    break;
                case "Acceptable":
                    $amazonCondition = 1;
                    break;
                default:
                    $amazonCondition = 0;
                }

            //echo $condition . "|" . $ourCondition . "|" . $amazonCondition . "|" . count($lowestPrices) . "|" . $totalFeedback . "|" . $merchantId . "<br/>";

            /* default lowest 4 */
            if(count($lowestPricesDefault[$a] < 4)){ //changed to 4 per new pricing specs
                $lowestPricesDefault[$a] = str_replace('$','',$offer->Price->ListingPrice->Amount);
                $a++;
            }

            if( ($ourCondition <= $amazonCondition) && ($totalFeedback >= 99) &&  (count($lowestPrices) < 4) ) //changed to 4 per new pricing specs
            {
                $lowestPrices[$x] = str_replace('$','',$offer->Price->ListingPrice->Amount);
                $x++;
            } 
        }
        $z++;
    }



    if(count($lowestPrices) > 0){
        $avgPrice = array_sum($lowestPrices)/count($lowestPrices);
        $source = "Amazon Condition Price";
    }else{
        //$avgPrice = $listPrice - ($listPrice * 0.25);
        $avgPrice = array_sum($lowestPricesDefault)/count($lowestPricesDefault);
        $source = "Default Pricing";
    }

    //make sure avg price is atleast 5.50, >236% of follett price, and >=200% of our cost
    if($avgPrice < ($follettPrice * 2.37)){
        $avgPrice = $follettPrice * 2.37;
        $source = "Follett Pricing";
    }
    if($avgPrice < ($row['cost'] * 2)){
        $avgPrice = $row['cost'] * 2;
        $source = "Double Cost";
    }
    if($avgPrice < 5.50){
        $avgPrice = 5.50;
        $source = "Lowest Base Cost";
    }

    //update fillzPrice
    $conn->query("UPDATE inventory SET ourPrice = $avgPrice WHERE sku=" . $row['sku']);

我在第二个程序的第 86 行收到错误，这是条件行 ($condition = $offer->Qualifiers->ItemSubcondition;) 有人知道为什么会这样吗？另外，有没有人有任何建议让它运行得更好？

4

1 回答 1

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首先，两个代码审查点：

  1. 您有变量$a、$x和$z，它们都没有初始条件，并且对于任何试图维护代码的人来说都是完全不透明的。单个$i作为循环计数器通常被认为是可以接受的，但是好的变量命名可以使调试更容易。
  2. 使用 SimpleXML 时，始终将值转换为字符串：$asin = $current->Identifiers->MarketplaceASIN->ASIN;应该阅读$asin = (string)$current->Identifiers->MarketplaceASIN->ASIN;除其他事项外，忘记这样做将意味着$asin永远无法将其保存到会话中（因为 SimpleXML 对象无法序列化）。

至于你的代码为什么失败，我认为你的循环结构是错误的：

while(count($lowestPrices) < 4 )
{
    foreach($currentPrice as $offer)
    {
        // Do something which may add to `$lowestPrices`
        $z++;
    }
}

首先，$z似乎没有用于任何事情。其次，可能会在循环$lowestPrices内部添加 0、1、4 甚至 100 次。foreach如果加到至少4次，while循环会立即退出（所以还不如不存在）；如果它被添加到少于 4 次，foreach循环将简单地在相同的数据上再次运行。我不清楚这是否会使其更有可能满足while循环条件，从而为您提供无限循环。

您内存不足的原因，而不仅仅是 CPU 时间，是额外的数组$lowestPricesDefault即使$lowestPrices没有增长，所以每次while循环（以及整个内部foreach循环）重复时它都会无限期地增长。

于 2012-08-24T13:41:58.007 回答