Sha*_*313 23 php server-sent-events
我目前正在进行一项使用Server-Sent Events接收消息的聊天.但是,我遇到了一个问题.服务器发送的事件从未连接并保持挂起状态,因为页面未加载.
例如:
<?php
while(true) {
echo "data: This is the message.";
sleep(3);
ob_flush();
flush();
}
?>
我希望每隔3秒,"数据:这就是消息." 将被输出.相反,页面只是不加载.但是,对于服务器发送的事件,我需要这种行为.有没有办法来解决这个问题？
编辑:
完整代码:
<?php
session_start();
require "connect.php";
require "user.php";
session_write_close();
echo $data["number"];
header("Content-Type: text/event-stream\n\n");
header('Cache-Control: no-cache');
set_time_limit(1200);
$store = new StdClass(); // STORE LATEST MESSAGES TO COMPARE TO NEW ONES
$ms = 200; // REFRESH TIMING (in ms)
$go = true; // MESSAGE CHANGED
function formateNumber ($n) {
$areaCode = substr($n, 0, 3);
$part1 = substr($n, 3, 3);
$part2 = substr($n, 6, 4);
return "($areaCode) $part1-$part2";
}
function shorten ($str, $mLen, $elp) {
if (strlen($str) <= $mLen) {
return $str;
} else {
return rtrim(substr($str, 0, $mLen)) . $elp;
}
}
do {
$number = $data["number"];
$sidebarQ = "
SELECT *
FROM (
SELECT *
FROM messages
WHERE deleted NOT LIKE '%$number%'
AND (
`from`='$number'
OR
`to`='$number'
)
ORDER BY `timestamp` DESC
) as mess
GROUP BY `id`
ORDER BY `timestamp` DESC";
$query = $mysqli->query($sidebarQ);
if ($query->num_rows == 0) {
echo 'data: null' . $number;
echo "\n\n";
} else {
$qr = array();
while($row = $query->fetch_assoc()) {
$qr[] = $row;
}
foreach ($qr as $c) {
$id = $c["id"];
if (!isset($store->{$id})) {
$store->{$id} = $c["messageId"];
$go = true;
} else {
if ($store->{$id} != $c["messageId"]) {
$go = true;
$store->{$id} = $c["messageId"];
}
}
}
if($go == true) {
$el = $n = "";
foreach ($qr as $rows) {
$to = $rows["to"];
$id = $rows["id"];
$choose = $to == $number ? $rows["from"] : $to;
$nameQuery = $mysqli->query("SELECT `savedname` FROM `contacts` WHERE `friend`='$choose' AND `number`='$number'");
$nameGet = $nameQuery->fetch_assoc();
$hasName = $nameQuery->num_rows == 0 ? formateNumber($choose) : $nameGet["savedname"];
$new = $mysqli->query("SELECT `id` FROM `messages` WHERE `to`='$number' AND `tostatus`='0' AND `id`='$id'")->num_rows;
if ($new > 0) {
$n = "<span class='new'>" . $new . "</span>";
}
$side = "<span style='color:#222'>" . ($to == $number ? "To you:" : "From you:") . "</span>";
$el .= "<div class='messageBox sBox" . ($nameQuery->num_rows == 0 ? " noname" : "") . "' onclick=\"GLOBAL.load($id, $choose)\" data-id='$id'><name>$hasName</name><div>$side " . shorten($rows["message"], 25, "...") . "</div>$n</div>";
}
echo 'data: '. $el;
echo "\n\n";
$go = false;
}
}
echo " ";
ob_flush();
flush();
sleep(2);
} while(true);
?>
我还要注意,这个无限循环不应该导致这种情况发生.这就是SSE的常规设置,甚至在MDN网站上也是如此.
毫无疑问,到目前为止你已经想到了这一点,但是在你没有使用的情况下我没有使用像下面的几个sse脚本的代码,它就像一个魅力.下面的代码是通用的,并没有你的sql或记录集处理,但想法是合理的(!？)
<?php
set_time_limit( 0 );
ini_set('auto_detect_line_endings', 1);
ini_set('mysql.connect_timeout','7200');
ini_set('max_execution_time', '0');
date_default_timezone_set( 'Europe/London' );
ob_end_clean();
gc_enable();
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
header('Access-Control-Allow-Credentials: true');
header('Access-Control-Allow-Methods: GET');
header('Access-Control-Expose-Headers: X-Events');
if( !function_exists('sse_message') ){
function sse_message( $evtname='chat', $data=null, $retry=1000 ){
if( !is_null( $data ) ){
echo "event:".$evtname."\r\n";
echo "retry:".$retry."\r\n";
echo "data:" . json_encode( $data, JSON_FORCE_OBJECT|JSON_HEX_QUOT|JSON_HEX_TAG|JSON_HEX_AMP|JSON_HEX_APOS );
echo "\r\n\r\n";
}
}
}
$sleep=1;
$c=1;
$pdo=new dbpdo();/* wrapper class for PDO that simplifies using PDO */
while( true ){
if( connection_status() != CONNECTION_NORMAL or connection_aborted() ) {
break;
}
/* Infinite loop is running - perform actions you need */
/* Query database */
/*
$sql='select * from `table`';
$res=$pdo->query($sql);
*/
/* Process recordset from db */
/*
$payload=array();
foreach( $res as $rs ){
$payload[]=array('message'=>$rs->message);
}
*/
/* prepare sse message */
sse_message( 'chat', array('field'=>'blah blah blah','id'=>'XYZ','payload'=>$payload ) );
/* Send output */
if( @ob_get_level() > 0 ) for( $i=0; $i < @ob_get_level(); $i++ ) @ob_flush();
@flush();
/* wait */
sleep( $sleep );
$c++;
if( $c % 1000 == 0 ){/* I used this whilst streaming twitter data to try to reduce memory leaks */
gc_collect_cycles();
$c=1;
}
}
if( @ob_get_level() > 0 ) {
for( $i=0; $i < @ob_get_level(); $i++ ) @ob_flush();
@ob_end_clean();
}
?>
虽然这不是问题的直接答案,但尝试使用此方法来查找错误..您没有收到错误,但这应该可以帮助您找到它们吗？
基本上你想要一个简单的PHP脚本,其中包含你的主脚本,但这个页面启用了错误...下面的示例..
index.php/Simple Error Includer
<?php
ini_set('display_errors',1);
ini_set('display_startup_errors',1);
error_reporting(-1);
require "other.php";
?>
other.php /你的主要剧本
<?php
ini_set('display_errors',1);
ini_set('display_startup_errors',1);
error_reporting(-1);
weqwe qweqeq
qweqweqweqwe
?>
如果您创建这样的设置,如果您查看index.php,您将看到以下错误,Parse error: syntax error, unexpected 'qweqeq' (T_STRING) in /var/www/html/syntax_errors/other.php on line 5因为它在主页上没有无效语法,并允许任何包含错误检查..
但是,如果您在哪里查看other.php,您只需获得一个白/空页面,因为它无法验证整个页面/脚本.
我在我的项目中使用这个方法,不管我在other.php或任何链接的php页面中做什么,我都会看到他们的错误报告.
请在评论之前理解代码 ,说这会禁用错误控制意味着您不必费心去RTM
填充缓冲区
我记得过去的另一个问题是在输出到浏览器之前填充缓冲区.所以在循环之前尝试这样的事情.
echo str_repeat("\n",4096); // Exceed the required browser threshold
for($i=0;$i<70;$i++) {
echo "something as normal";
flush();
sleep(1);
}
http://www.sitepoint.com/php-streaming-output-buffering-explained/上的示例
小智 5
似乎睡眠功能正在干扰输出。将睡眠功能置于AFTERWARDS之后确实起作用：
<?php
while(true) {
echo "data: This is the message.";
ob_flush();
flush();
sleep(3);
}
正如其他人所建议的那样，我鼓励使用AJAX而不是无限循环，但这不是您的问题。
下面的代码在这里工作正常，还使用 Mayhem 他的 str_repeat 函数添加 4k 数据（这通常是 php 刷新 tcp 数据包的最小值）
echo str_repeat(' ', 4096);
while(true)
{
echo "data: This is the message.";
flush();
sleep(3);
}