EventBufferEvent::connectHost
(PECL event >= 1.2.6-beta)
EventBufferEvent::connectHost — Connects to a hostname with optionally asyncronous DNS resolving
說明
EventDnsBase
$dns_base
,string
$hostname
,int
$port
,int
$family
= EventUtil::AF_UNSPEC
): bool
Resolves the DNS name hostname, looking for addresses of type
family
(
EventUtil::AF_*
constants). If the name resolution fails, it invokes the event callback
with an error event. If it succeeds, it launches a connection attempt just
as
EventBufferEvent::connect()
would.
dns_base
is optional. May be null, or an object created with
EventDnsBase::__construct()
. For asyncronous hostname resolving pass a valid event dns base resource.
Otherwise the hostname resolving will block.
注意:
EventDnsBase is available only if
Eventconfigured --with-event-extra (event_extralibrary, libevent protocol-specific functionality support including HTTP, DNS, and RPC ).
注意:
EventBufferEvent::connectHost() requires
libevent-2.0.3-alphaor greater.
參數
-
dns_base -
Object of EventDnsBase in case if DNS is to be resolved asyncronously. Otherwise
null. -
hostname -
Hostname to connect to. Recognized formats are:
www.example.com (hostname) 1.2.3.4 (ipv4address) ::1 (ipv6address) [::1] ([ipv6address])
-
port -
Port number
-
family -
Address family.
EventUtil::AF_UNSPEC,EventUtil::AF_INET, orEventUtil::AF_INET6. See EventUtil constants .
返回值
成功時返回 true， 或者在失敗時返回 false。
範例
示例 #1 EventBufferEvent::connectHost() example
<?php
/* Read callback */
function readcb($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 $buf;
}
}
/* Event callback */
function eventcb($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, /* use internal socket */ NULL,
EventBufferEvent::OPT_CLOSE_ON_FREE | EventBufferEvent::OPT_DEFER_CALLBACKS,
"readcb", /* writecb */ NULL, "eventcb", $base
);
if (!$bev) {
exit("Failed creating bufferevent socket\n");
}
//$bev->setCallbacks("readcb", /* writecb */ 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();
?>
以上例程的輸出類似於：
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
參見
- EventBufferEvent::connect() - Connect buffer event's file descriptor to given address or UNIX socket