Examples

Example #1 Simple HTTP client

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

The above example will output something similar to:

 Connected. HTTP/1.1 301 Moved Permanently Date: Fri, 01 Mar 2013 18:47:48 GMT Location: http://www.google.co.uk/ Content-Type: text/html; charset=UTF-8 Cache-Control: public, max-age=2592000 Server: gws Content-Length: 221 X-XSS-Protection: 1; mode=block X-Frame-Options: SAMEORIGIN Age: 133438 Expires: Sat, 30 Mar 2013 05:39:28 GMT Connection: close <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 

Example #2 HTTP client using asynchronous DNS resolver

<?php


// Read callback
function readcb($bev, $base) {
$input = $bev->getInput();

while ((
$n = $input->remove($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();

echo
"step 1\n";
$bev = new EventBufferEvent($base, NULL,
EventBufferEvent::OPT_CLOSE_ON_FREE | EventBufferEvent::OPT_DEFER_CALLBACKS);
if (!
$bev) {
exit(
"Failed creating bufferevent socket\n");
}

echo
"step 2\n";
$bev->setCallbacks("readcb", NULL, "eventcb", $base);
$bev->enable(Event::READ | Event::WRITE);

echo
"step 3\n";
// Send request
$output = $bev->getOutput();
if (!
$output->add(
"GET /index.cphp HTTP/1.0\r\n".
"Connection: Close\r\n\r\n"
)) {
exit(
"Failed adding request to output buffer\n");
}


if (!$bev->connect("127.0.0.1:80")) {
exit(
"Can't connect to host\n");
}

// Dispatch pending events
$base->dispatch();
?>

Example #3 Echo server

<?php


class MyListenerConnection {
private
$bev, $base;

public function
__destruct() {
$this->bev->free();
}

public function
__construct($base, $fd) {
$this->base = $base;

$this->bev = new EventBufferEvent($base, $fd, EventBufferEvent::OPT_CLOSE_ON_FREE);

$this->bev->setCallbacks(array($this, "echoReadCallback"), NULL,
array(
$this, "echoEventCallback"), NULL);

if (!
$this->bev->enable(Event::READ)) {
echo
"Failed to enable READ\n";
return;
}
}

public function
echoReadCallback($bev, $ctx) {
// Copy all the data from the input buffer to the output buffer

Example #4 SSL echo server

<?php


class MySslEchoServer {
public
$port,
$base,
$bev,
$listener,
$ctx;

function
__construct ($port, $host = "127.0.0.1") {
$this->port = $port;
$this->ctx = $this->init_ssl();
if (!
$this->ctx) {
exit(
"Failed creating SSL context\n");
}

$this->base = new EventBase();
if (!
$this->base) {
exit(
"Couldn't open event base\n");
}

$this->listener = new EventListener($this->base,
array(
$this, "ssl_accept_cb"), $this->ctx,
EventListener::OPT_CLOSE_ON_FREE | EventListener::OPT_REUSEABLE,
-
1, "$host:$port");
if (!
$this->listener) {
exit(
"Couldn't create listener\n");
}

$this->listener->setErrorCallback(array($this, "accept_error_cb"));
}
function
dispatch() {
$this->base->dispatch();
}

// This callback is invoked when there is data to read on $bev.
function ssl_read_cb($bev, $ctx) {
$in = $bev->input; //$bev->getInput();

printf("Received %zu bytes\n", $in->length);
printf("----- data ----\n");
printf("%ld:\t%s\n", (int) $in->length, $in->pullup(-1));

$bev->writeBuffer($in);
}

// This callback is invoked when some even occurs on the event listener,

Example #5 Signal handler

<?php

class MyEventSignal {
private
$base;

function
__construct($base) {
$this->base = $base;
}

function
eventSighandler($no, $c) {
echo
"Caught signal $no\n";
event_base_loopexit($c->base);
}
}

$base = event_base_new();
$c = new MyEventSignal($base);
$no = SIGTERM;
$ev = evsignal_new($base, $no, array($c,'eventSighandler'), $c);

evsignal_add($ev);

event_base_loop($base);
?>

Example #6 Use libevent's loop to process requests of `eio' extension

<?php
// Callback for eio_nop()
function my_nop_cb($d, $r) {
echo
"step 6\n";
}

$dir = "/tmp/abc-eio-temp";
if (
file_exists($dir)) {
rmdir($dir);
}

echo
"step 1\n";

$base = new EventBase();

echo
"step 2\n";

eio_init();

eio_mkdir($dir, 0750, EIO_PRI_DEFAULT, "my_nop_cb");

$event = new Event($base, eio_get_event_stream(),
Event::READ | Event::PERSIST, function ($fd, $events, $base) {
echo
"step 5\n";

while (
eio_nreqs()) {
eio_poll();
}

$base->stop();
},
$base);

echo
"step 3\n";

$event->add();

echo
"step 4\n";

$base->dispatch();

echo
"Done\n";
?>

Example #7 Miscellaneous

<?php

echo "Supported methods:\n";
foreach (
Event::getSupportedMethods() as $m) {
echo
$m, PHP_EOL;
}

// Avoiding "select" method
$cfg = new EventConfig();
if (
$cfg->avoidMethod("select")) {
echo
"'select' method avoided\n";
}

// Create event_base associated with the config
$base = new EventBase($cfg);
echo
"Event method used: ", $base->getMethod(), PHP_EOL;

echo
"Features:\n";
$features = $base->getFeatures();
(
$features & EventConfig::FEATURE_ET) and print "ET - edge-triggered IO\n";
(
$features & EventConfig::FEATURE_O1) and print "O1 - O(1) operation for adding/deleting events\n";
(
$features & EventConfig::FEATURE_FDS) and print "FDS - arbitrary file descriptor types, and not just sockets\n";

// Require FDS feature
if ($cfg->requireFeatures(EventConfig::FEATURE_FDS)) {
echo
"FDS feature is now required\n";

$base = new EventBase($cfg);
(
$base->getFeatures() & EventConfig::FEATURE_FDS)
and print
"FDS - arbitrary file descriptor types, and not just sockets\n";
}



$base = new EventBase();
$event = new Event($base, STDIN, Event::READ | Event::PERSIST, function ($fd, $events, $arg) {
static
$max_iterations = 0;

if (++
$max_iterations >= 5) {

echo "Stopping...\n";
$arg[0]->exit(2.33);
}

echo
fgets($fd);
}, array (&
$base));

$event->add();
$base->loop();

?>

Example #8 Simple HTTP server

<?php


function _http_dump($req, $data) {
static
$counter = 0;
static
$max_requests = 2;

if (++
$counter >= $max_requests) {
echo
"Counter reached max requests $max_requests. Exiting\n";
exit();
}

echo
__METHOD__, " called\n";
echo
"request:"; var_dump($req);
echo
"data:"; var_dump($data);

echo
"\n===== DUMP =====\n";
echo
"Command:", $req->getCommand(), PHP_EOL;
echo
"URI:", $req->getUri(), PHP_EOL;
echo
"Input headers:"; var_dump($req->getInputHeaders());
echo
"Output headers:"; var_dump($req->getOutputHeaders());

echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";

echo
"\n >> Reading input buffer ...\n";
$buf = $req->getInputBuffer();
while (
$s = $buf->readLine(EventBuffer::EOL_ANY)) {
echo
$s, PHP_EOL;
}
echo
"No more data in the buffer\n";
}

function
_http_about($req) {
echo
__METHOD__, PHP_EOL;
echo
"URI: ", $req->getUri(), PHP_EOL;
echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";
}

function
_http_default($req, $data) {
echo
__METHOD__, PHP_EOL;
echo
"URI: ", $req->getUri(), PHP_EOL;
echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";
}

$port = 8010;
if (
$argc > 1) {
$port = (int) $argv[1];
}
if (
$port <= 0 || $port > 65535) {
exit(
"Invalid port");
}

$base = new EventBase();
$http = new EventHttp($base);
$http->setAllowedMethods(EventHttpRequest::CMD_GET | EventHttpRequest::CMD_POST);

$http->setCallback("/dump", "_http_dump", array(4, 8));
$http->setCallback("/about", "_http_about");
$http->setDefaultCallback("_http_default", "custom data value");

$http->bind("0.0.0.0", 8010);
$base->loop();
?>

The above example will output something similar to:

 a=12 HTTP/1.0 200 OK Content-Type: text/html; charset=ISO-8859-1 Connection: close HTTP/1.0 200 OK Content-Type: text/html; charset=ISO-8859-1 Connection: close (press Enter) HTTP/1.0 200 OK Content-Type: text/html; charset=ISO-8859-1 Connection: close 

Example #9 Simple HTTPS server

<?php


function _http_dump($req, $data) {
static
$counter = 0;
static
$max_requests = 200;

if (++
$counter >= $max_requests) {
echo
"Counter reached max requests $max_requests. Exiting\n";
exit();
}

echo
__METHOD__, " called\n";
echo
"request:"; var_dump($req);
echo
"data:"; var_dump($data);

echo
"\n===== DUMP =====\n";
echo
"Command:", $req->getCommand(), PHP_EOL;
echo
"URI:", $req->getUri(), PHP_EOL;
echo
"Input headers:"; var_dump($req->getInputHeaders());
echo
"Output headers:"; var_dump($req->getOutputHeaders());

echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";

$buf = $req->getInputBuffer();
echo
"\n >> Reading input buffer (", $buf->length, ") ...\n";
while (
$s = $buf->read(1024)) {
echo
$s;
}
echo
"\nNo more data in the buffer\n";
}

function
_http_about($req) {
echo
__METHOD__, PHP_EOL;
echo
"URI: ", $req->getUri(), PHP_EOL;
echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";
}

function
_http_default($req, $data) {
echo
__METHOD__, PHP_EOL;
echo
"URI: ", $req->getUri(), PHP_EOL;
echo
"\n >> Sending reply ...";
$req->sendReply(200, "OK");
echo
"OK\n";
}

function
_http_400($req) {
$req->sendError(400);
}

function
_init_ssl() {
$local_cert = __DIR__."/ssl-echo-server/cert.pem";
$local_pk = __DIR__."/ssl-echo-server/privkey.pem";

$ctx = new EventSslContext(EventSslContext::SSLv3_SERVER_METHOD, array (
EventSslContext::OPT_LOCAL_CERT => $local_cert,
EventSslContext::OPT_LOCAL_PK => $local_pk,
//EventSslContext::OPT_PASSPHRASE => "test",
EventSslContext::OPT_ALLOW_SELF_SIGNED => true,
));

return
$ctx;
}

$port = 9999;
if (
$argc > 1) {
$port = (int) $argv[1];
}
if (
$port <= 0 || $port > 65535) {
exit(
"Invalid port");
}
$ip = '0.0.0.0';

$base = new EventBase();
$ctx = _init_ssl();
$http = new EventHttp($base, $ctx);
$http->setAllowedMethods(EventHttpRequest::CMD_GET | EventHttpRequest::CMD_POST);

$http->setCallback("/dump", "_http_dump", array(4, 8));
$http->setCallback("/about", "_http_about");
$http->setCallback("/err400", "_http_400");
$http->setDefaultCallback("_http_default", "custom data value");

$http->bind($ip, $port);
$base->dispatch();

Example #10 OpenSSL connection

<?php


function _request_handler($req, $base) {
echo
__FUNCTION__, PHP_EOL;

if (
is_null($req)) {
echo
"Timed out\n";
} else {
$response_code = $req->getResponseCode();

if (
$response_code == 0) {
echo
"Connection refused\n";
} elseif (
$response_code != 200) {
echo
"Unexpected response: $response_code\n";
} else {
echo
"Success: $response_code\n";
$buf = $req->getInputBuffer();
echo
"Body:\n";
while (
$s = $buf->readLine(EventBuffer::EOL_ANY)) {
echo
$s, PHP_EOL;
}
}
}

$base->exit(NULL);
}

function
_init_ssl() {
$ctx = new EventSslContext(EventSslContext::SSLv3_CLIENT_METHOD, array ());

return
$ctx;
}


// Allow to override the port
$port = 9999;
if (
$argc > 1) {
$port = (int) $argv[1];
}
if (
$port <= 0 || $port > 65535) {
exit(
"Invalid port\n");
}
$host = '127.0.0.1';

$ctx = _init_ssl();
if (!
$ctx) {
trigger_error("Failed creating SSL context", E_USER_ERROR);
}

$base = new EventBase();
if (!
$base) {
trigger_error("Failed to initialize event base", E_USER_ERROR);
}

$conn = new EventHttpConnection($base, NULL, $host, $port, $ctx);
$conn->setTimeout(50);

$req = new EventHttpRequest("_request_handler", $base);
$req->addHeader("Host", $host, EventHttpRequest::OUTPUT_HEADER);
$buf = $req->getOutputBuffer();
$buf->add("<html>HTML TEST</html>");
//$req->addHeader("Content-Length", $buf->length, EventHttpRequest::OUTPUT_HEADER);
//$req->addHeader("Connection", "close", EventHttpRequest::OUTPUT_HEADER);
$conn->makeRequest($req, EventHttpRequest::CMD_POST, "/dump");

$base->dispatch();
echo
"END\n";
?>

Example #11 EventHttpConnection::makeRequest() example

<?php
function _request_handler($req, $base) {
echo
__FUNCTION__, PHP_EOL;

if (
is_null($req)) {
echo
"Timed out\n";
} else {
$response_code = $req->getResponseCode();

if (
$response_code == 0) {
echo
"Connection refused\n";
} elseif (
$response_code != 200) {
echo
"Unexpected response: $response_code\n";
} else {
echo
"Success: $response_code\n";
$buf = $req->getInputBuffer();
echo
"Body:\n";
while (
$s = $buf->readLine(EventBuffer::EOL_ANY)) {
echo
$s, PHP_EOL;
}
}
}

$base->exit(NULL);
}

$address = "127.0.0.1";
$port = 80;

$base = new EventBase();
$conn = new EventHttpConnection($base, NULL, $address, $port);
$conn->setTimeout(5);
$req = new EventHttpRequest("_request_handler", $base);

$req->addHeader("Host", $address, EventHttpRequest::OUTPUT_HEADER);
$req->addHeader("Content-Length", "0", EventHttpRequest::OUTPUT_HEADER);
$conn->makeRequest($req, EventHttpRequest::CMD_GET, "/index.cphp");

$base->loop();
?>

The above example will output something similar to:

 _request_handler Success: 200 Body: PHP, date: 2013-03-13T20:27:52+05:00 

Example #12 Connection listener based on a UNIX domain socket

<?php


class MyListenerConnection {
private
$bev, $base;

public function
__destruct() {
if (
$this->bev) {
$this->bev->free();
}
}

public function
__construct($base, $fd) {
$this->base = $base;

$this->bev = new EventBufferEvent($base, $fd, EventBufferEvent::OPT_CLOSE_ON_FREE);

$this->bev->setCallbacks(array($this, "echoReadCallback"), NULL,
array(
$this, "echoEventCallback"), NULL);

if (!
$this->bev->enable(Event::READ)) {
echo
"Failed to enable READ\n";
return;
}
}

public function
echoReadCallback($bev, $ctx) {
// Copy all the data from the input buffer to the output buffer
$bev->output->addBuffer($bev->input);
}

public function
echoEventCallback($bev, $events, $ctx) {
if (
$events & EventBufferEvent::ERROR) {
echo
"Error from bufferevent\n";
}

if (
$events & (EventBufferEvent::EOF | EventBufferEvent::ERROR)) {
$bev->free();
$bev = NULL;
}
}
}

class
MyListener {
public
$base,
$listener,
$socket;
private
$conn = array();

public function
__destruct() {
foreach (
$this->conn as &$c) $c = NULL;
}

public function
__construct($sock_path) {
$this->base = new EventBase();
if (!
$this->base) {
echo
"Couldn't open event base";
exit(
1);
}

if (
file_exists($sock_path)) {
unlink($sock_path);
}

$this->listener = new EventListener($this->base,
array(
$this, "acceptConnCallback"), $this->base,
EventListener::OPT_CLOSE_ON_FREE | EventListener::OPT_REUSEABLE, -1,
"unix:$sock_path");

if (!
$this->listener) {
trigger_error("Couldn't create listener", E_USER_ERROR);
}

$this->listener->setErrorCallback(array($this, "accept_error_cb"));
}

public function
dispatch() {
$this->base->dispatch();
}

// This callback is invoked when there is data to read on $bev
public function acceptConnCallback($listener, $fd, $address, $ctx) {
// We got a new connection! Set up a bufferevent for it. */
$base = $this->base;
$this->conn[] = new MyListenerConnection($base, $fd);
}

public function
accept_error_cb($listener, $ctx) {
$base = $this->base;

fprintf(STDERR, "Got an error %d (%s) on the listener. "
."Shutting down.\n",
EventUtil::getLastSocketErrno(),
EventUtil::getLastSocketError());

$base->exit(NULL);
}
}

if (
$argc <= 1) {
exit(
"Socket path is not provided\n");
}
$sock_path = $argv[1];

$l = new MyListener($sock_path);
$l->dispatch();
?>

Example #13 Simple SMTP server

<?php


class Handler {
public
$domainName = FALSE;
public
$connections = [];
public
$buffers = [];
public
$maxRead = 256000;

public function
__construct() {
$this->ctx = new EventSslContext(EventSslContext::SSLv3_SERVER_METHOD, [
EventSslContext::OPT_LOCAL_CERT => 'cert.pem',
EventSslContext::OPT_LOCAL_PK => 'privkey.pem',
//EventSslContext::OPT_PASSPHRASE => '',
EventSslContext::OPT_VERIFY_PEER => false, // change to true with authentic cert
EventSslContext::OPT_ALLOW_SELF_SIGNED => true // change to false with authentic cert
]);

$this->base = new EventBase();
if (!
$this->base) {
exit(
"Couldn't open event base\n");
}

if (!
$this->listener = new EventListener($this->base,
[
$this, 'ev_accept'],
$this->ctx,
EventListener::OPT_CLOSE_ON_FREE | EventListener::OPT_REUSEABLE,
-
1,
'0.0.0.0:25'))
{
exit(
"Couldn't create listener\n");
}

$this->listener->setErrorCallback([$this, 'ev_error']);
$this->base->dispatch();
}

public function
ev_accept($listener, $fd, $address, $ctx) {
static
$id = 0;
$id += 1;

$this->connections[$id]['clientData'] = '';
$this->connections[$id]['cnx'] = new EventBufferEvent($this->base, $fd,
EventBufferEvent::OPT_CLOSE_ON_FREE);

if (!
$this->connections[$id]['cnx']) {
echo
"Failed creating buffer\n";
$this->base->exit(NULL);
exit(
1);
}

$this->connections[$id]['cnx']->setCallbacks([$this, "ev_read"], NULL,
[
$this, 'ev_error'], $id);
$this->connections[$id]['cnx']->enable(Event::READ | Event::WRITE);

$this->ev_write($id, '220 '.$this->domainName." wazzzap?\r\n");
}

function
ev_error($listener, $ctx) {
$errno = EventUtil::getLastSocketErrno();

fprintf(STDERR, "Got an error %d (%s) on the listener. Shutting down.\n",
$errno, EventUtil::getLastSocketError());

if (
$errno != 0) {
$this->base->exit(NULL);
exit();
}
}

public function
ev_close($id) {
$this->connections[$id]['cnx']->disable(Event::READ | Event::WRITE);
unset(
$this->connections[$id]);
}

protected function
ev_write($id, $string) {
echo
'S('.$id.'): '.$string;
$this->connections[$id]['cnx']->write($string);
}

public function
ev_read($buffer, $id) {
while(
$buffer->input->length > 0) {
$this->connections[$id]['clientData'] .= $buffer->input->read($this->maxRead);
$clientDataLen = strlen($this->connections[$id]['clientData']);

if(
$this->connections[$id]['clientData'][$clientDataLen-1] == "\n"
&& $this->connections[$id]['clientData'][$clientDataLen-2] == "\r")
{
// remove the trailing \r\n
$line = substr($this->connections[$id]['clientData'], 0,
strlen($this->connections[$id]['clientData']) - 2);

$this->connections[$id]['clientData'] = '';
$this->cmd($buffer, $id, $line);
}
}
}

protected function
cmd($buffer, $id, $line) {
switch (
$line) {
case
strncmp('EHLO ', $line, 4):
$this->ev_write($id, "250-STARTTLS\r\n");
$this->ev_write($id, "250 OK ehlo\r\n");
break;

case
strncmp('HELO ', $line, 4):
$this->ev_write($id, "250-STARTTLS\r\n");
$this->ev_write($id, "250 OK helo\r\n");
break;

case
strncmp('QUIT', $line, 3):
$this->ev_write($id, "250 OK quit\r\n");
$this->ev_close($id);
break;

case
strncmp('STARTTLS', $line, 3):
$this->ev_write($id, "220 Ready to start TLS\r\n");
$this->connections[$id]['cnx'] = EventBufferEvent::sslFilter($this->base,
$this->connections[$id]['cnx'], $this->ctx,
EventBufferEvent::SSL_ACCEPTING,
EventBufferEvent::OPT_CLOSE_ON_FREE);
$this->connections[$id]['cnx']->setCallbacks([$this, "ev_read"], NULL, [$this, 'ev_error'], $id);
$this->connections[$id]['cnx']->enable(Event::READ | Event::WRITE);
break;

default:
echo
'unknown command: '.$line."\n";
break;
}
}
}

new
Handler();
To Top