Flake

A fork from https://github.com/sony/sonyflake

Flake is a distributed unique ID generator inspired by Twitter's Snowflake.

Differences from the original Sonyflake:

• panic instead of returning errors, as these errors are mostly non actionable and should never occur: NextID() uint64
• time units are 1 msec instead of 10
• 16 bits for a machine id,
• 6 bits for a sequence number (64 per 1 ms)
• 41 bits for time in units of 1 msec

As a result, Flake has the following advantages and disadvantages:

• The lifetime (69 years) is similar to that of Snowflake (69 years)
• It can work on more distributed machines (2^16) than Snowflake (2^10)
• It can generate 2^6 IDs per 1 msec at most in a single machine/thread

Installation

go get github.com/effective-security/xdb/pkg/flake

Usage

The function NewIDGenerator creates a new IDGenerator instance.

func NewIDGenerator(st Settings) IDGenerator

You can configure Flake by the struct Settings:

type Settings struct {
	StartTime      time.Time
	MachineID      func() (uint16, error)
	CheckMachineID func(uint16) bool
}

• StartTime is the time since which the Flake time is defined as the elapsed time. If StartTime is 0, the start time of the Sonyflake is set to "2021-01-01 00:00:00 +0000 UTC". If StartTime is ahead of the current time, Flake is not created.

• MachineID returns the unique ID of the Flake instance. If MachineID returns an error, Flake will panic. If MachineID is nil, default MachineID is used. Default MachineID returns the lower 8 bits of the private IP address.

• CheckMachineID validates the uniqueness of the machine ID. If CheckMachineID returns false, Flake will panic. If CheckMachineID is nil, no validation is done.

In order to get a new unique ID, you just have to call the method NextID.

func (sf *Flake) NextID() uint64

License

The MIT License (MIT)