chh/einhorn

Library for communicating with an Einhorn parent process.

Installs: 1

Dependents: 0

Stars: 4

Watchers: 2

Language: PHP

v0.4.0 2012-12-17 18:08 UTC

README

A simple utility belt for using PHP with Einhorn.

Install

Put this into your composer.json:

{
    "require": {
        "chh/einhorn": "*@dev"
    }
}

Install it:

% php composer.phar install

Then setup the autoloader:

<?php

require("vendor/autoload.php");

Usage

Communicate with the Master Process

A Einhorn\Client is used to communicate with the Einhorn Master Process. The simplest way to retrieve a client is through the worker's client method.

<?php

use Einhorn\Worker;

$client = Worker::client();

The client method takes the discovery method for the control socket as first argument and an optional second argument, which can be used by the specific discovery strategy.

Following discovery strategies are supported out-of-the-box:

  • DISCOVER_ENV: Looks for an environment variable named EINHORN_SOCK_PATH which contains the path to the master's control Unix Socket.
  • DISCOVER_FD: Looks for an environment variable named EINHORN_FD which contains the file descriptor number for the master's control socket. This is mainly useful with Einhorn's -b switch.
  • DISCOVER_DIRECT: Opens the path passed as second argument as Unix Socket. Useful when opening an connection the control socket from outside of a worker script for monitoring etc.

Example:

<?php

use Einhorn\Worker;

$client = Worker::client(Worker::DISCOVER_FD);
$client->ack();

The client also features a command method to send arbitary commands to the master process.

Client::command(array $command)

The command argument is an array which contains at least an command key which contains the name of the command to invoke on the master.

For commands which return a response, the recv method should be called after sending the command.

Example:

<?php

user Einhorn\Worker;

$client = Worker::client();

$client->command(array("command" => "state"));

$state = $client->recv();

Manual ACK

The client features a ack method which sends an worker:ack command with the current process' PID to the Einhorn Master Process, in case you've launched einhorn with -m manual.

Example:

<?php

use Einhorn\Worker;

$client = Worker::client();
$client->ack();

File Descriptor Number to PHP Stream

The Worker class features an utility method which returns a PHP stream for the file descriptor number passed in by Einhorn. This stream can then be used with stream_select or stream_socket_accept.

Example:

<?php

use Einhorn\Worker;

# Returns the first socket found in `EINHORN_FDS` environment variable
$socket = Worker::socket();

# Returns all sockets bound via the -b flag
$sockets = Worker::sockets();

# When the FD number is passed by other means:
$socket = Worker::socket($fd);

Changelog

v0.4.0

  • Added Worker::sockets() which returns an array of streams, created from all file descriptor numbers in EINHORN_FDS.
  • Use EINHORN_SOCK_FD instead of EINHORN_FD to discover the file descriptor number of the control socket when the -g flag is passed to Einhorn and the DISCOVER_FD strategy is used to find the control process.

License

Copyright (c) 2012 Christoph Hochstrasser

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.