Snowflake53

A trait to generate 53 bits snowflake id to fit into js Number.MAX_SAFE_INTEGER. Sequence counting is done with shared memory and machine ID comes from environment variable or parameters It also possible to generate 64 bits snowflake id.

It dosen't require any external infrastructure (like Memcached or Redis or ...) to keep sequence counting as it is done by shared memory and use semaphore for locking. So other processes can tap into the sequence counting too :)

Install

Via composer :

$ composer require artnum/snowflake53

Usage

require_once 'vendor/autoload.php';

use Snowflake53\ID;

class IDGen {
    use ID;
}

$gen = new IDGen();
echo $gen->get53() . PHP_EOL;
echo $gen->get64() . PHP_EOL;

All functions are declared as static, so it is possible to use without a class instance.

require_once 'vendor/autoload.php';

use Snowflake53\ID;

class IDGen {
    use ID;
}

echo IDGen::get53() . PHP_EOL;
echo IDGen::get64() . PHP_EOL;

You can destroy, if you choose to, shared memory semgent and semaphore by calling destroySHM:

require_once 'vendor/autoload.php';

use Snowflake53\ID;

class IDGen {
    use ID;
}

IDGen::destroySHM(); 

Shared memory path

Shared memory use a file path as identity. By default it is __FILE__. But if you use this in several different places on your server but still want all ID to be in sequence, you can set the public static variable $SHMPath to the path you want. The file must exist.

require_once 'src/Snowflake53.php';

use Snowflake53\ID;

class IDGen {
    use ID;
}

IDGen::$SHMPath = '/tmp/snowflake53';
echo IDGen::get53() . PHP_EOL;
echo IDGen::get64() . PHP_EOL;


$gen = new IDGen();
$gen::$SHMPath = '/tmp/snowflake53';
echo $gen->get53() . PHP_EOL;
echo $gen->get64() . PHP_EOL;

Machine ID

Machine ID can be passed as argument of get53 or get64. If not, it will try to get the ID from environment variable SNOWFLAK53_MACHINE_ID, SNOWFLAKE64_MACHINE_ID or SNOWFLAKE_MACHINE_ID. When getting a 53 bits ID, SNOWFLAK53_MACHINE_ID will be look at and then SNOWFLAKE_MACHINE_ID, when getting a 64 bits ID it's the opposite (first SNOWFLAKE64_MACHINE_ID and then SNOWFLAKE_MACHINE_ID).

The idea behind that is you set a unique machine for 64 and 53 bits and so, you use SNOWFLAKE_MACHINE_ID or you have a different machine ID for 53 bits or 64 bits and so you set SNOWFLAKE53_MACHINE_ID and SNOWFLAKE64_MACHINE_ID.

License

Under MIT license.

Developer

• Etienne Bagnoud etienne@artnum.ch