yusitnikov/php-elock-client

Simple eLock client on PHP

1.2.0 2018-11-12 07:13 UTC

Requires

• ext-json: *
• psr/log: ^1.0

MIT

• Yura Sitnikov

README

Simple eLock client on PHP. Also supports features of NodeJS eLock server.

What is eLock?

eLock is a simple distributed lock server on erlang.

Advantages:

• fault-tolerant
• simple to install and to use
• safe from race conditions - all operations are atomic
• all locks required by a client are being unlocked automatically when the client disconnects

See source repository.

What is NodeJS eLock server?

NodeJS eLock server is an implementation of original eLock protocol on NodeJS with an addition of deadlock detection.

Advantages:

• all advantages of original eLock protocol
• when lock attempt causes a recursive lock circle, a deadlock is automatically reported with 423 response code
• supports value locks
• has "debug" command

See source repository.

Install eLock server

Original eLock server

1. Install erlang OTP
2. Install and run eLock server

NodeJS eLock server

1. Install NodeJS/npm
2. Install and run eLock server

It would be listening on port 11400.

Install eLock client

The client is available as a composer dependency:

composer install yusitnikov/php-elock-client

Use eLock client

Basic usage

$key1 = 'unique-resource-key1';
$key1 = 'unique-resource-key2';
$lockTimeout = 5;

// Create a client of an original eLock server
$client = new ELockClient('your.elock.server.host.or.ip');
// or create a client of a NodeJS eLock server
$client = new ELockClientEx('your.elock.server.host.or.ip');

// Tell to release all locks after the disconnection
$client->setTimeout(0);

// Lock keys
$lockedKey1 = $client->lock($key1, $lockTimeout);
$lockedKey2 = $client->lock($key2, $lockTimeout);

// Unlock key
$unlockedKey1 = $client->unlock($key1);

// Unlock all keys you own
$client->unlockAll();

// Disconnect from the server
$client->quit();
$client->close();

Common usage for atomic operations

// Lock the resource with a timeout that's big enough to wait for other clients to finish their job
if (!$client->lock($key, $timeout)) {
    throw new Exception('Failed to lock the resource XXX during YYY seconds');
}

try {
    // Do something with the locked resource
} finally {
    // Ensure that the resource will be unlocked in the case of unexpected error
    $client->unlock($key);
}