, (*1)
, (*2)
Hoa is a modular, extensible and
structured set of PHP libraries.
Moreover, Hoa aims at being a bridge between industrial and research worlds.
, (*3)
Hoa\Socket
, (*4)
This library provides an abstract layer to build safe, fast and modular clients
and servers., (*5)
It represents a connection as a stream (please, see the Hoa\Stream
library) that is used
to build clients and servers. A connection supports timeout, options, context,
encryption, remote informations etc. Such a connection, along with an abstract
connection handler, allows to embed and “merge” many connections inside the same
processus side-by-side., (*6)
Learn more., (*7)
Installation
With Composer, to include this library into
your dependencies, you need to
require hoa/socket:, (*8)
$ composer require hoa/socket '~1.0'
For more installation procedures, please read the Source
page., (*9)
Testing
Before running the test suites, the development dependencies must be installed:, (*10)
$ composer install
Then, to run all the test suites:, (*11)
$ vendor/bin/hoa test:run
For more information, please read the contributor
guide., (*12)
Quick usage
As a quick overview, we will look at creating a server and a client, and
introduce the respective API., (*13)
A connection behind
Both server and client extend a connection, namely the
Hoa\Socket\Connection\Connection class, which is a stream represented by the
Hoa\Stream library.
This latter provides the common stream API whose the read and write methods
(from Hoa\Stream\IStream\In, Hoa\Stream\IStream\Out and also
Hoa\Stream\IStream\Pathable). Since it is also responsible of the connection,
we are able to manipulate the underlying socket resource, the timeout, the
different flags, the stream context, the encryption, the remote informations
etc., (*14)
To start a connection, we will use the connect method (the constructor does
not start the connection by itself). For a server, we will often prefer to use
the connectAndWait method (see bellow). To stop a connection, most of the
time, we will use the disconnect method., (*15)
A remote connection (a client for the server, a server for the client) is
represented by a node: an object that holds several informations about the
remote connection. The default node is Hoa\Socket\Node and can be easily
extended. To use a new node, we have to call the
Hoa\Socket\Connection\Connection::setNodeName method., (*16)
A connection needs a socket URI, represented by the Hoa\Socket\Socket class,
to know where to connect. This latter represents an IPv4 or IPv6 address, a
domain or a path (for Unix socket), along with the transport scheme (tcp://,
udp:// etc.) and the port., (*17)
Manipulating a server or a client
We will instanciate the Hoa\Socket\Server class and start a connection to
tcp://127.0.0.1:4242. Then, to select active nodes,
we will use the Hoa\Socket\Connection\Connection::select method that returns
an iterator. Finally, we will read a line and write an uppercassed echo. Thus:, (*18)
$server = new Hoa\Socket\Server('tcp://127.0.0.1:4242');
$server->connectAndWait();
while (true) {
foreach ($server->select() as $node) {
$line = $server->readLine();
if (empty($line)) {
$server->disconnect();
continue;
}
echo '< ', $line, "\n";
$server->writeLine(strtoupper($line));
}
}
And then, with telnet:, (*19)
$ telnet 127.0.0.1 4242
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
foobar
FOOBAR
hello world
HELLO WORLD
From the server, we will see:, (*20)
< foobar
< hello world
To reproduce the same behavior with our own client, we will write (thanks to
Hoa\Console\Readline\Readline, please see the Hoa\Console
library):, (*21)
$client = new Hoa\Socket\Client('tcp://127.0.0.1:4242');
$client->connect();
$readline = new Hoa\Console\Readline\Readline();
while (true) {
$line = $readline->readLine('> ');
if ('quit' === $line) {
break;
}
$client->writeLine($line);
echo '< ', $client->readLine(), "\n";
}
Finally:, (*22)
$ php Client.php
> foobar
< FOOBAR
> hello world
< HELLO WORLD
> quit
Handle servers and clients
A connection has advanced operations but they are low-levels and not obvious.
Moreover, there is repetitive and not so trivial tasks that we need often, such
as broadcasting messages. The Hoa\Socket\Connection\Handler provides an easy
way to create and embed a very flexible server or client. (A good and complete
example is the Hoa\Websocket
library)., (*23)
We will focus on a server. A server has the magic run method that starts an
infinite loop and make some computation on active nodes. This is basically the
while (true) in our previous examples. In addition, we would like to easily
send a message to a specific node, or send a message to all nodes except one.
The Hoa\Socket\Connection\Handler class asks the user to implement only two
methods: _run and _send, and provides the run method, along with send
and broadcast. Then, we no longer need to start the connection or to take care
about the implementation of different network topologies. All is managed by the
handler. Thus:, (*24)
class MyServer extends Hoa\Socket\Connection\Handler
{
protected function _run (Hoa\Socket\Node $node)
{
$connection = $node->getConnection();
$line = $connection->readLine();
if (empty($line)) {
$connection->disconnect();
return;
}
echo '< ', $line, "\n";
$this->send(strtoupper($line));
return;
}
protected function _send ($message, Hoa\Socket\Node $node)
{
return $node->getConnection()->writeLine($message);
}
}
And then, all we need to do is:, (*25)
$server = new MyServer(new Hoa\Socket\Server('tcp://127.0.0.1:4242'));
$server->run();
We see that the connection is embeded inside our server, and that all the logic
has been moved inside the _run method. If we change the call to send by
broadcast, we will see all connected clients receiving the message, something
like:, (*26)
echo '< ', $line, "\n";
$this->broadcast(strtoupper($line));
The _send method gives an implementation of “sending one message”, which is
the basis. Because the _run method does not start an infinite loop, we have
more flexibility (see the next section)., (*27)
We can add listeners (please see the Hoa\Event
library) to
interact with the server, something like $server->on('message', function ( … )
{ … }); etc., (*28)
Merging connections
Another huge advantage of using handlers is that they can be used inside a
Hoa\Socket\Connection\Group object. The run method is an infinite loop, so
we are not able to run two servers side-by-side in the same process.
Fortunately, the Hoa\Socket\Connection\Group allows to “merge” connections
(this is an underlying feature of Hoa\Socket\Connection\Connection but a group
abstracts and manages all the complexity). Consequently, we are able to run
several servers and clients together, inside the same processus, at the same
time., (*29)
For example, we will run an instance of Hoa\Irc\Client (please, see the
Hoa\Irc library) with a
Hoa\Websocket\Server (please, see the Hoa\Websocket
library: all
messages received by the WebSocket server will be redirected on the IRC client.
Thus:, (*30)
$websocket = new Hoa\Websocket\Server(new Hoa\Socket\Server('tcp://…'));
$irc = new Hoa\Irc\Client(new Hoa\Socket\Client('tcp://…'));
$group = new Hoa\Socket\Connection\Group();
$group[] = $websocket;
$group[] = $irc;
$websocket->on(
'message',
function (Hoa\Event\Bucket $bucket) use ($irc) {
$data = $bucket->getData();
$irc->say($data['message']);
return;
}
);
// $irc->…
$group->run();
This is an illustration of the power provided by the Hoa\Socket\Connection
classes., (*31)
Documentation
The
hack book of Hoa\Socket contains
detailed information about how to use this library and how it works., (*32)
To generate the documentation locally, execute the following commands:, (*33)
$ composer require --dev hoa/devtools
$ vendor/bin/hoa devtools:documentation --open
More documentation can be found on the project's website:
hoa-project.net., (*34)
Getting help
There are mainly two ways to get help:, (*35)
Contribution
Do you want to contribute? Thanks! A detailed contributor
guide explains
everything you need to know., (*36)
License
Hoa is under the New BSD License (BSD-3-Clause). Please, see
LICENSE for details., (*37)
The following projects are using this library:, (*38)
Wallogit.com
