EventBufferEvent::connectHost

(PECL event >= 1.2.6-beta)

EventBufferEvent::connectHost — Connects to a hostname with optionally asyncronous DNS resolving

说明

public bool EventBufferEvent::connectHost ( EventDnsBase $dns_base , string $hostname , int $port [, int $family = EventUtil::AF_UNSPEC ] )

Resolves the DNS name hostname, looking for addresses of type family ( EventUtil::AF_* constants). If the name resolution fails, it invokes the event callback with an error event. If it succeeds, it launches a connection attempt just as EventBufferEvent::connect() would.

dns_base is optional. May be NULL , or an object created with EventDnsBase::__construct() . For asyncronous hostname resolving pass a valid event dns base resource. Otherwise the hostname resolving will block.

Note:

EventDnsBase is available only if Event configured --with-event-extra ( event_extra library, libevent protocol-specific functionality support including HTTP, DNS, and RPC ).

Note:

EventBufferEvent::connectHost() requires libevent-2.0.3-alpha or greater.

参数

dns_base

Object of EventDnsBase in case if DNS is to be resolved asyncronously. Otherwise NULL .

hostname

Hostname to connect to. Recognized formats are:

www.example.com (hostname)
 1.2.3.4 (ipv4address)
 ::1 (ipv6address)
[::1] ([ipv6address])

port

Port number

family

Address family. EventUtil::AF_UNSPEC , EventUtil::AF_INET , or EventUtil::AF_INET6 . See EventUtil constants .

返回值

Returns TRUE on success. Otherwise FALSE .

范例

Example #1 EventBufferEvent::connectHost() example

  <?php
 
 function  readcb ( $bev ,  $base ) {
     //$input = $bev->input; //$bev->getInput();

    //$pos = $input->search("TTP");
     $pos  =  $bev -> input -> search ( "TTP" );

    while (( $n  =  $bev -> input -> remove ( $buf ,  1024 )) >  0 ) {
        echo  $buf ;
    }
}

 
 function  eventcb ( $bev ,  $events ,  $base ) {
    if ( $events  &  EventBufferEvent :: CONNECTED ) {
        echo  "Connected.\n" ;
    } elseif ( $events  & ( EventBufferEvent :: ERROR  |  EventBufferEvent :: EOF )) {
        if ( $events  &  EventBufferEvent :: ERROR ) {
            echo  "DNS error: " ,  $bev -> getDnsErrorString (),  PHP_EOL ;
        }

        echo  "Closing\n" ;
         $base -> exit ();
        exit( "Done\n" );
    }
}

 $base  = new  EventBase ();

 $dns_base  = new  EventDnsBase ( $base ,  TRUE );  // We'll use async DNS resolving
 if (! $dns_base ) {
    exit( "Failed to init DNS Base\n" );
}

 $bev  = new  EventBufferEvent ( $base ,    NULL ,
     EventBufferEvent :: OPT_CLOSE_ON_FREE  |  EventBufferEvent :: OPT_DEFER_CALLBACKS ,
     "readcb" ,    NULL ,  "eventcb" ,  $base
 );
if (! $bev ) {
    exit( "Failed creating bufferevent socket\n" );
}

 //$bev->setCallbacks("readcb",  NULL, "eventcb", $base);
 $bev -> enable ( Event :: READ  |  Event :: WRITE );

 $output  =  $bev -> output ;  //$bev->getOutput();
 if (! $output -> add (
     "GET  { $argv [ 2 ]}  HTTP/1.0\r\n" .
     "Host:  { $argv [ 1 ]} \r\n" .
     "Connection: Close\r\n\r\n"
 )) {
    exit( "Failed adding request to output buffer\n" );
}

if (! $bev -> connectHost ( $dns_base ,  $argv [ 1 ],  80 ,  EventUtil :: AF_UNSPEC )) {
    exit( "Can't connect to host  { $argv [ 1 ]} \n" );
}

 $base -> dispatch ();
 ?>

以上例程的输出类似于：

Connected.
HTTP/1.0 301 Moved Permanently
Location: http://www.google.co.uk/
Content-Type: text/html; charset=UTF-8
Date: Sat, 09 Mar 2013 12:21:19 GMT
Expires: Mon, 08 Apr 2013 12:21:19 GMT
Cache-Control: public, max-age=2592000
Server: gws
Content-Length: 221
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>301 Moved</TITLE></HEAD><BODY>
<H1>301 Moved</H1>
The document has moved
<A HREF="http://www.google.co.uk/">here</A>.
</BODY></HTML>
Closing
Done

参见

EventBufferEvent::connect() - Connect buffer event's file descriptor to given address or UNIX socket