php - LONG POLLING(在 php 中)在对数据库发出 5 次请求后开始挂起

Question

我正在开发具有实时投标系统的现场拍卖网站。当用户对项目出价时，我正在使用 LONG POLLING。我选择了长轮询，因为 WebSockets 还没有得到很好的支持，而且 NODEJS 对我来说现在实现起来太复杂了。所以我坚持使用这种简单的 ajax 长轮询，它非常适合大约五个出价。

所以问题是: 出价非常适合 1 秒间隔内的 5-6 个项目出价(我从 server-ajax 得到即时响应)，但是第 7 个(点击)出价按钮这个响应-long 轮询挂起大约 16-22 秒，然后完成请求。最后，所有内容都在数据库中更新并完成，但在每 5-6 个投标响应/ajax 调用后挂起大约 16-22 秒。

我怎样才能减少这个时间，无论用户出价多少次，一切都应该顺利，没有延迟...

我在 localhost/wamp 上使用 Apache/PHP/MySql

我的代码:index.php

<script type="text/javascript" charset="utf-8">             
var old_timestamp = <?php echo $old_timestamp;?>; //here i'm echoing last timestamp of         auction

function waitForMsg(){
jq.ajax({
type: "POST",
url: "http://localhost/bid/comet/poll.php",
data: {"old_timestamp" : old_timestamp},
async: true,
cache: false,

success: function(data){
var json = eval('(' + data + ')');
if(json['msg'] != "") {
jq('#comet_display').html(json['msg']); //here I show ID of which auction item was bidded
}
old_timestamp = json['old_timestamp']; 
setTimeout('waitForMsg()',100);
},
error: function(XMLHttpRequest, textStatus, errorThrown){

setTimeout('waitForMsg()',1000);
}
});
}

jq(window).load(function(){ 
waitForMsg();
jq("#a_loader").show();
    var url = "http://localhost/bid/auctions-ajax"; // the script where you handle the form input.  
    jq.ajax({
           type: "POST",
           url: url,
           data: {au978 : true}, 
           async:false, //to sem dodal za časovni zamik
           success: function(data)
           {
             jq("#a_loader").hide();  
             jq("#show-category").html(data); // show response from the php script.              
           },
            error: function(result) {
                jq("#show-category").html("Sorry, something went wrong. Please try again later.");
            }
    });

});

function bid(id){

var url = "http://localhost/bid/comet/update-auction.php"; // the script where you handle the form input.
var user_id=<?php echo $user_id;?>; //user id from session
jq.ajax({
    type: "POST",
    url: url,
    data: {"auct_id" : id, "user_id" : user_id}, // serializes the form's elements.
    success: function(data)
    {
        //it updates in user table its remaining number of bids 
    },
    error: function(XMLHttpRequest, textStatus, errorThrown){
        alert("Something went wrong. Click OK to refresh.");

    }
});
}

</script>

poll.php

<?php

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
require_once($_SERVER['DOCUMENT_ROOT'] . 'bid/include/DEFINES.php');
require_once(CLASS_AUCTION);
require_once(CLASS_DB);

$a=new Auction();

$old_timestamp = $_POST['old_timestamp']; 
$bidded_id=0;
$db=DB::getInstance();  
$sql="SELECT timestamp, id FROM auction ORDER BY timestamp DESC LIMIT 1";   //desno doda tabelo kategorija  
$stmt=$db->db->prepare($sql) or die("Prepare Error");   
$stmt->execute();   
$result2=$stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($result2 as $rez){
    $current_timestamp=$rez['timestamp'];   
    $bidded_id=$rez['id'];
}
$stmt->closeCursor();


    while($current_timestamp <= $old_timestamp){
    usleep(1000);
    clearstatcache();
    $db=DB::getInstance();  
    $sql="SELECT timestamp, id FROM auction ORDER BY timestamp DESC LIMIT 1";       
    $stmt=$db->db->prepare($sql) or die("Prepare Error");   
    $stmt->execute();   
    $result=$stmt->fetchAll(PDO::FETCH_ASSOC);
    foreach ($result as $rez){
        $current_timestamp=$rez['timestamp'];   
        $bidded_id=$rez['id'];
    }
    $stmt->closeCursor();

}
$response = array();
$response['msg'] = 'BID na avkciji: '.$bidded_id;
$response['old_timestamp'] = $current_timestamp;
echo json_encode($response);
 }else{
require_once($_SERVER['DOCUMENT_ROOT'] . 'bid/errors/404.html');
 }
?>

和 update-auction.php

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
require_once($_SERVER['DOCUMENT_ROOT'] . 'bid/include/DEFINES.php');
require_once(CLASS_AUCTION);
require_once(CLASS_USER);
require_once(CLASS_DB);
$u=new User(); 
$a=new Auction();
$auction_id=$_POST['auct_id'];
$user_id=$_POST['user_id'];
$date = new DateTime();
$timestamp=$date->getTimestamp();
$a->updateAuction($auction_id,$user_id,$timestamp/*,$bid_price,$bids_spent,$total_paid*/);
$u->updateUserBids($user_id);

}else{
require_once($_SERVER['DOCUMENT_ROOT'] . 'bid/errors/404.html');
}
?>

感谢您查看我的问题!

Answer 1

考虑切换到 WebSockets。它旨在解决长轮询问题。