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CombGenerator

CombGenerator generates COMBs (combined UUID/timestamp)

The CombGenerator, when used with the StringCodec (and, by proxy, the TimestampLastCombCodec) or the TimestampFirstCombCodec, combines the current timestamp with a UUID (hence the name "COMB"). The timestamp either appears as the first or last 48 bits of the COMB, depending on the codec used.

By default, COMBs will have the timestamp set as the last 48 bits of the identifier.

$factory = new UuidFactory();

$factory->setRandomGenerator(new CombGenerator(
    $factory->getRandomGenerator(),
    $factory->getNumberConverter()
));

$comb = $factory->uuid4();

To generate a COMB with the timestamp as the first 48 bits, set the TimestampFirstCombCodec as the codec.

$factory->setCodec(new TimestampFirstCombCodec($factory->getUuidBuilder()));

See Also:

  • https://www.informit.com/articles/printerfriendly/25862 - The Cost of GUIDs as Primary Keys

Constants

Constant Visibility Type Value
TIMESTAMP_BYTES public 6

Properties

generator

private \Ramsey\Uuid\Generator\RandomGeneratorInterface $generator

numberConverter

private \Ramsey\Uuid\Converter\NumberConverterInterface $numberConverter

Methods

__construct

public __construct(\Ramsey\Uuid\Generator\RandomGeneratorInterface $generator, \Ramsey\Uuid\Converter\NumberConverterInterface $numberConverter): mixed

Parameters:

Parameter Type Description
$generator \Ramsey\Uuid\Generator\RandomGeneratorInterface
$numberConverter \Ramsey\Uuid\Converter\NumberConverterInterface

generate

Generates a string of randomized binary data

public generate(int $length): string

Parameters:

Parameter Type Description
$length int The number of bytes of random binary data to generate

Return Value:

A binary string

Throws:

if $length is not a positive integer greater than or equal to CombGenerator::TIMESTAMP_BYTES

timestamp

Returns current timestamp a string integer, precise to 0.00001 seconds

private timestamp(): string

Automatically generated on 2025-03-18