实现一个简单的服务端推送方案-实例篇Polling(服务端阻塞读,SLEE_MySQL

前面讲过一篇《实现一个简单的服务端推送方案-实例篇Polling(服务端阻塞读)》，那篇文章服务端利用Gearman队列来实现阻塞读，这篇服务器端用原生MySQL的Sleep函数来实现阻塞读，这篇文章也是另一篇文章《使用MySQL构建一个队列表》的实例实现。

客户端代码，JS库为prototype.js：

 "."maxvid: ".$maxvid."/n", 3 , "/usr/local/apache2219/logs/php_log");$dblnk = mysql_connect('localhost:3306', 'root', 'cpyf');mysql_select_db('test', $dblnk);if ( $maxvid <= 0 ) {  $result = mysql_query("select max(vid) from vdooropen");  $result = mysql_fetch_row($result);  $maxvid = $result[0];  error_log(date("[Y-m-d H:i:s]")." > "."maxvid: ".$maxvid."/n", 3 , "/usr/local/apache2219/logs/php_log");}while (1){  $result = mysql_query("select * from vdooropen where vid > $maxvid order by vid limit 1");  $num = mysql_num_rows($result);  if ( $num > 0 ) break;  mysql_query("/*!999999 wait queue msg */ SELECT SLEEP(300)");  if ( mysql_errno() != 0 ) {    mysql_close($dblnk);  //必须先关闭    $dblnk = mysql_connect('localhost:3306', 'root', 'cpyf');    mysql_select_db('test', $dblnk);  }}$result = mysql_fetch_row($result);// 返回 JSON 数组$response = array();$response['vid'] = $result[0];$response['msg'] = $result[0].",".$result[1].",".$result[2].",".$result[3].",".$result[4];$responseText = json_encode($response);error_log(date("[Y-m-d H:i:s]")." < ".$responseText."/n", 3 , "/usr/local/apache2219/logs/php_log");echo $responseText;flush();?>