Freelance client, Model Two in PHP

<?php
/*

  • Freelance Client - Model 2
  • Uses DEALER socket to blast one or more services

*

  • Author: Rob Gagnon <rgagnon24(at)gmail(dot)com>

*/

class FLClient
{
const GLOBAL_TIMEOUT = 2500; // ms

private $servers = 0;
private $sequence = 0;
/** @var ZMQContext */
private $context = null;
/** @var ZMQSocket */
private $socket = null;

public function __construct()
{
$this->servers = 0;
$this->sequence = 0;
$this->context = new ZMQContext();
$this->socket = $this->context->getSocket(ZMQ::SOCKET_DEALER);
}

public function __destruct()
{
$this->socket->setSockOpt(ZMQ::SOCKOPT_LINGER, 0);
$this->socket = null;
$this->context = null;
}

/**
* @param string $endpoint
*/

public function connect($endpoint)
{
$this->socket->connect($endpoint);
$this->servers++;
printf("I: Connected to %s\n", $endpoint);
}

/**
* @param string $request
*/

public function request($request)
{
// Prefix request with sequence number and empty envelope
$this->sequence++;
$msg = array('', $this->sequence, $request);

// Blast the request to all connected servers
for ($server = 1; $server <= $this->servers; $server++) {
$this->socket->sendMulti($msg);
}

// Wait for a matching reply to arrive from anywhere
// Since we can poll several times, calculate each one
$poll = new ZMQPoll();
$poll->add($this->socket, ZMQ::POLL_IN);

$reply = null;
$endtime = time() + self::GLOBAL_TIMEOUT / 1000;
while (time() < $endtime) {
$readable = $writable = array();
$events = $poll->poll($readable, $writable, ($endtime - time()) * 1000);
foreach ($readable as $sock) {
if ($sock == $this->socket) {
$reply = $this->socket->recvMulti();
if (count($reply) != 3) {
exit;
}
$sequence = $reply[1];
if ($sequence == $this->sequence) {
break;
}
}
}
}

return $reply;
}
}

$cmd = array_shift($argv);
if (count($argv) == 0) {
printf("I: syntax: %s <endpoint> …\n", $cmd);
exit;
}

// Create new freelance client object
$client = new FLClient();

foreach ($argv as $endpoint) {
$client->connect($endpoint);
}

$start = time();
for ($requests = 0; $requests < 10000; $requests++) {
$request = "random name";
$reply = $client->request($request);
if (!isset($reply)) {
print "E: name service not available, aborting\n";
break;
}
}

printf("Average round trip cost: %i ms\n", ((time() - $start) / 100));
$client = null;