DistributedUIDGenerator

Description

The default key generator. It produces a distributed unique id, Snowflake-style, that combines a timestamp, a machine id, and a per-millisecond sequence.

The generated ids are non-sequential, so several users can add keys to the same table without id collisions. The id packs a per-millisecond sequence (12 bits), a machine id (10 bits), and a timestamp measured from DistributedUIDGenerator.CustomEpoch (41 bits). Timestamps count from a fixed default epoch of 2020-01-01T00:00:00Z, and every generator in the process draws from one sequence counter, so two default generators created at the same moment still hand out different ids. The machine id is derived from SystemInfo.deviceUniqueIdentifier so it is stable per machine. Assign an instance to SharedTableData.KeyGenerator to control how a collection assigns key ids, or implement IKeyGenerator for a different scheme.

Additional resources: IKeyGenerator, SharedTableData

Generate two ids and confirm they differ.

using Unity.Localization;
using UnityEngine;

namespace Unity.Localization.Samples
{
    public class DistributedUIDGeneratorOverviewExample
    {
        public void Run()
        {
            var generator = new DistributedUIDGenerator();

            var first = generator.GetNextKey();
            var second = generator.GetNextKey();

            Debug.Log(first != second);   // True: ids are unique
        }
    }
}

Properties

Constructors

Public Methods