Temporally Ordered IDs. Generate universally unique identifiers (UUID) that sort lexically in time order.
Torid exists to solve the problem of generating UUIDs that when ordered lexically, they are also ordered temporally. I needed a way to generate ids for events that are entering a system with the following criteria:
- Fast ID generation
- No central coordinating server/system
- No local storage
- Library code, that is multiple apps on the same machine can use the same code and they will not generate duplicate ids
- Eventually stored in a UUID field in a database. So 128bit ids are totally fine.
The IDs that Torid generates are 128bit IDs made up of 2, 64bit parts.
- 64bit microsecond level UNIX timestamp
- 64bit hash of the system hostname, process id and a random value.
require 'torid'
uuid = Torid.uuid
uuid.to_s # => "0004fda4-318e-f380-5a45-5321cd065b02"
uuid.bytes # => "\x00\x04\xFD\xA41\x8E\xF3\x80ZES!\xCD\x06[\x02"require 'torid'
generator = Torid::Generator.new
uuid = generator.next
uuid.to_s # => "0004fda4-3f42-3d01-4731-5a4aa8ddd6c3"
uuid.bytes # => "\x00\x04\xFD\xA4?B=\x01G1ZJ\xA8\xDD\xD6\xC3"The vast majority of the credit and research stems from:
- jondot's blog post on Fast ID Generation served to solidify my thoughts on the criteria I needed in an ID generation system.
- This let me to Boundary's Flake
- James Golick's lexical_uuid, which if I had found a day earlier, I might be using instead of creating this.
You could consider Torid to be a reimplementation of lexical_uuid. It definately steals some code from it and simple_uuid
Blog posts around ID generation:
- Wikipedia UUID
- RFC 4122
- Fast ID Generation Part I
- Boundary's Flake Project
- Flickr's Ticket Server
- Twitter Snowflake
- Sharding & ID's at Instagram
Libraries implementing similar approaches:
http://opensource.org/licenses/isc-license.txt
Copyright (c) 2014 Jeremy Hinegardner
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