ExKsuid

Fully featured KSUID module in Elixir

KSUID (K-Sortable unique ID) is a way to generate ID (like to UUID), which use 4 byte of timestamp and 16 byte of random data.

KSUID can be lexicographically sort for rough ordering (at second resolution) of when KSUID is generated, in DB, sorting by KSUID as primary key usually faster than sorting inserted_at or updated_at

Example:

Example (KSUID in Base62) 1czONudbZwh5siu2igQJY94QkFH

This module can:

• Generate KSUID in Base62/Raw byte format, with specific input on timestamp & random payload
• Parse KSUID to get it's timestamp part and random payload part
• Provide Ecto Schema basic Type for use as field/primary key, either in Base62 or Raw byte

more information on https://github.com/segmentio/ksuid

Common Usage

# Generate KSUID (simple)
ExKsuid.generate()
## 1czONudbZwh5siu2igQJY94QkFH

# Parse information in KSUID
result = ExKsuid.parse("1czONudbZwh5siu2igQJY94QkFH")
## %{
##   random_bytes: <<78, 137, 74, 76, 6, 99, 179, 98, 179, 99, 109, 200, 247, 175,
##     171, 187>>,
##   timestamp: 1591527918
## }
DateTime.from_unix(result.timestamp)
## {:ok, ~U[2020-06-07 11:05:18Z]}

# Filter all KSUID after 2020-02-15 timestamp
data = [~U[2020-01-01 00:00:00Z], ~U[2020-02-01 00:00:00Z], ~U[2020-03-01 00:00:00Z], ~U[2020-04-01 00:00:00Z], ~U[2020-05-01 00:00:00Z]]
data = data |> Enum.map(& ExKsuid.generate(timestamp: &1 |> DateTime.to_unix()))
## ["1Vlny8xRAj9lht9c0DsxpbBK8Gi", "1XBMnOgQG7Gm7S63kPjiW0EqIlM",
## "1YVHNQAFJsvQgtQvcLlpdeW1FCY", "1ZuqCjUj9tluPXTyU2q45w3ZwiW",
## "1bHZuH1adLPe8PjgHwYz7JPHVHx"]
ksuid = ExKsuid.generate(timestamp: ~U[2020-02-15 00:00:00Z] |> DateTime.to_unix())
## 1XouWeBxLmlTwhaLqOu4a7SPLp7
data |> Enum.filter(fn d -> d > ksuid end) |> Enum.map(fn d -> 
  result = ExKsuid.parse(d)
  DateTime.from_unix!(result.timestamp)
end)
## [~U[2020-03-01 00:00:00Z], ~U[2020-04-01 00:00:00Z], ~U[2020-05-01 00:00:00Z]]

# Use in Ecto Schema
defmodule Account do
  use Ecto.Schema

  @primary_key {:ksuid, ExKsuid.EctoType, autogenerate: true}
  schema "account" do
    field :name, :string
    field :email, :string
  end
end

Comparison

elixir-ksuid is established module for generating KSUID in elixir

ExKsuid get inspiration from elixir-ksuid. In comparison, ExKsuid has several advantage like:

• Generate KSUID based on timestamp & custom random source
• Generate Raw byte KSUID, which is smaller (20 byte) than usual base62 format (27 byte)

Installation

The package can be installed by adding ex_ksuid to your list of dependencies in mix.exs:

def deps do
  [
    {:ex_ksuid, "~> 0.2.0"}
  ]
end