NGuid 0.2.0

NGuid

NGuid provides efficient creation of name-based and random GUIDs according to RFC 4122 and the current revision working draft:

• Version 3 - created from an MD5 hash of a name
• Version 5 - created from a SHA1 hash of a name
• Version 6 - a field-compatible version of UUIDv1, reordered for improved DB locality
• Version 7 - a time-ordered value based on a Unix timestamp
• Version 8 - an RFC-compatible format for experimental or vendor-specific use cases

Usage

// returns a "Version 5" UUID by default: {74738ff5-5367-5958-9aee-98fffdcd1876}
var guid = GuidHelpers.CreateFromName(GuidHelpers.DnsNamespace, "www.example.org"u8);

// can also create "Version 3": {0012416f-9eec-3ed4-a8b0-3bceecde1cd9}
var guidv3 = GuidHelpers.CreateFromName(GuidHelpers.DnsNamespace, "www.example.org"u8, version: 3);

Experimental

The following APIs are based on the current working draft and are subject to change:

// converts {6ba7b810-9dad-11d1-80b4-00c04fd430c8} to {1d19dad6-ba7b-6810-80b4-00c04fd430c8}
var guidv6 = GuidHelpers.CreateVersion6FromVersion1(GuidHelpers.DnsNamespace);

// creates a v7 GUID using the current time and random data 
var guidv7 = GuidHelpers.CreateVersion7();

// .NET 8 only: specify a TimeProvider to provide the timestamp
var guidv7WithTime = GuidHelpers.CreateVersion7(TimeProvider.System);

// creates a v8 GUID using the specified data
ReadOnlySpan<byte> bytes = GetBytes();
var guidv8 = GuidHelpers.CreateVersion8(bytes);

// creates a name-based v8 GUID using the specified hash algorithm
var guidv8ForName = GuidHelpers.CreateVersion8FromName(HashAlgorithmName.SHA256,
    GuidHelpers.DnsNamespace, "www.example.com"u8);