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ajax長輪詢 怎樣節省性能,AJAX長輪詢:如何使此代碼進行長輪詢?

在我了解長輪詢之前,我有這個代碼:

var updateMessages = function() {

var conv_id = [];

var lastMessages = [];

$('.user').each(function(){

conv_id.push($(this).find('p').attr('id'));

});

if($('.rightP').find('.msg .msg_block').length!=0){

$('.rightP').find('.msg .msg_block').each(function(){

if(($('.rightP').find('.msg .msg_block p').length)==0){

}else {

lastMessages.push($(this).find('p:last-child')[0].dataset.created_at);

}

});

}

$.ajax({

type: "POST",

url: 'create/populate',

data: {

'from': lastMessages,

'conv_id':conv_id

},

success: function(messages) {

console.log(messages);

$.each(messages, function() {

appendMessage(this);

});

},

error: function(xhr,textStatus,errorThrown) {

console.log(xhr.responseText);

},

complete: function() {

window.setTimeout(updateMessages, 2000);

},

dataType: 'json'

});

};

updateMessages();

然而,有人評論此代碼不是長輪詢。是以我研究并調整了上面的一些代碼:

...

complete: function() {

updateMessages(); //also tried updateMessages;

},

timeout:30000,

dataType: 'json'

...

但它遇到了諸如根本不輪詢的問題,并且消息不會更新。如何調整原始代碼進行長輪詢?改進代碼是一個獎勵。謝謝!

gente note:我不使用遺留浏覽器相容性問題的網絡套接字bcoz。我也不使用nodejs,因為我的共享伺服器不允許長時間運作的程序。

PHP代碼(在我的控制器中)

public function index()

{

$timestamps = Input::get('from'); //timestamp of latest message

$conv_id = Input::get('conv_id');

$allMessages = Messages::whereIn('conv_id',$conv_id);

if(is_null($timestamps)){

$messages = $allMessages->orderBy('created_at','desc')->take(10);

}else{

asort($timestamps);

$messages = $allMessages->where('created_at','>',end($timestamps));

}

return $messages->get()->reverse();

}