generate method

String generate({
  1. V7Options? options,
})

v7() Generates a time-based version 7 UUID

By default it will generate a string based off current time in Unix Epoch, and will return a string.

The first argument is an options map that takes various configuration options detailed in the readme.

https://datatracker.ietf.org/doc/html/draft-ietf-uuidrev-rfc4122bis#name-uuid-version-7

Implementation

String generate({V7Options? options}) {
  var buf = Uint8List(16);
  int time = options?.time ?? DateTime.timestamp().millisecondsSinceEpoch;

  var timeList48 = Uint8List.fromList([
    time ~/ pow(2, 40),
    time ~/ pow(2, 32),
    time ~/ pow(2, 24),
    time ~/ pow(2, 16),
    time ~/ pow(2, 8),
    time
  ]);

  buf.setAll(0, timeList48);
  List<int> randomBytes = options?.randomBytes ??
      (goptions?.rng?.generate() ?? V7State.random.generate());

  buf.setRange(6, 16, randomBytes);
  buf.setRange(6, 7, [buf.getRange(6, 7).last & 0x0f | 0x70]);
  buf.setRange(8, 9, [buf.getRange(8, 9).last & 0x3f | 0x80]);

  return UuidParsing.unparse(buf);
}