Add UUID v6

Use uuid identifiers module attributes in uuid6/1 Build the UUID v6 instead of converting a v1 Add uuid1<->uuid6 conversion functions Add some more validations to tests
zyro · Oct 13, 2020 · af154d6 · af154d6
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diff --git a/README.md b/README.md
@@ -62,6 +62,19 @@ iex> UUID.uuid5("fcfe5f21-8a08-4c9a-9f97-29d2fd6a27b9", "my.domain.com")
 "b8e85535-761a-586f-9c04-0fb0df2cbe84"
 ```
 
+### UUID v6
+
+Generated using a combination of time since the west adopted the gregorian calendar and either the node id MAC address or random bytes.
+Valid node types are `:mac_address` or `:random_bytes` and defaults to `:mac_address`.
+
+```elixir
+iex> UUID.uuid6()
+"1eb0d1d0-126a-6495-9a93-171634969e27"
+
+iex> UUID.uuid6(:random_bytes)
+"1eb0d1d5-c3fa-6b2e-8d7a-ef182baf6b94"
+```
+
 ### Formatting
 
 All UUID generator functions have an optional format parameter as the last argument.

diff --git a/lib/uuid.ex b/lib/uuid.ex
@@ -13,6 +13,7 @@ defmodule UUID do
   @uuid_v3 3 # UUID v3 identifier.
   @uuid_v4 4 # UUID v4 identifier.
   @uuid_v5 5 # UUID v5 identifier.
+  @uuid_v6 6 # UUID v6 identifier.
 
   @urn "urn:uuid:" # UUID URN prefix.
 
@@ -450,6 +451,114 @@ defmodule UUID do
     "Invalid argument; Expected: :dns|:url|:oid|:x500|:nil OR String, String"
   end
 
+  @doc """
+  Generate a new UUID v6. This version uses a combination of one or more of:
+  unix epoch, random bytes, pid hash, and hardware address.
+
+  Accepts a `node_type` argument that can be either `:mac_address` or
+  `:random_bytes`. Defaults to `:mac_address`. However, if there is a security
+  concern with using a MAC address, use `:random_bytes`.
+
+  See the [RFC draft, section 3.3](https://tools.ietf.org/html/draft-peabody-dispatch-new-uuid-format-00#section-3.3)
+  for more information on the node parts.
+
+  ## Examples
+
+      iex> UUID.uuid6()
+      "1eb0d28f-da4c-6eb2-adc1-0242ac120002"
+
+      iex> UUID.uuid6(:random_bytes, :default)
+      "1eb0d297-eb1e-62a6-a37f-a55eda5dd6e4"
+
+      iex> UUID.uuid6(:random_bytes, :hex)
+      "1eb0d298502563fcadcd25e5d0a44c1a"
+
+      iex> UUID.uuid6(:random_bytes, :urn)
+      "urn:uuid:1eb0d298-ca10-6914-ab0e-7d7e1e6e1808"
+
+      iex> UUID.uuid6(:random_bytes, :raw)
+      <<30, 176, 210, 153, 52, 23, 102, 230, 164, 146, 99, 66, 4, 72, 220, 114>>
+
+      iex> UUID.uuid6(:random_bytes, :slug)
+      "HrDSmab8ZnqR4SKw4LN-UA"
+
+  """
+  def uuid6(node_type \\ :mac_address, format \\ :default)
+      when node_type in [:mac_address, :random_bytes] do
+    uuid6(uuid1_clockseq(), uuid6_node(node_type), format)
+  end
+
+  @doc """
+  Generate a new UUID v6, with an existing clock sequence and node address. This
+  version uses a combination of one or more of: unix epoch, random bytes,
+  pid hash, and hardware address.
+  """
+  def uuid6(<<clock_seq::14>>, <<node::48>>, format) do
+    <<time_hi::12, time_mid::16, time_low::32>> = uuid1_time()
+    <<time_low1::20, time_low2::12>> = <<time_low::32>>
+    <<clock_seq_hi::6, clock_seq_low::8>> = <<clock_seq::14>>
+
+    <<time_hi::12, time_mid::16, time_low1::20, @uuid_v6::4, time_low2::12,
+      @variant10::2, clock_seq_hi::6, clock_seq_low::8, node::48>>
+      |> uuid_to_string(format)
+  end
+  def uuid6(_, _, _) do
+    raise ArgumentError, message:
+    "Invalid argument; Expected: <<clock_seq::14>>, <<node::48>>"
+  end
+
+  @doc """
+  Convert a UUID v1 to a UUID v6 in the same format.
+
+  ## Examples
+
+      iex> UUID.uuid1_to_uuid6("dafc431a-0d21-11eb-adc1-0242ac120002")
+      "1eb0d21d-afc4-631a-adc1-0242ac120002"
+
+      iex> UUID.uuid1_to_uuid6("2vxDGg0hEeutwQJCrBIAAg")
+      "HrDSHa_EYxqtwQJCrBIAAg"
+
+      iex> UUID.uuid1_to_uuid6(<<218, 252, 67, 26, 13, 33, 17, 235, 173, 193, 2, 66, 172, 18, 0, 2>>)
+      <<30, 176, 210, 29, 175, 196, 99, 26, 173, 193, 2, 66, 172, 18, 0, 2>>
+
+  """
+  def uuid1_to_uuid6(uuid1) do
+    {format, ub1} = uuid_string_to_hex_pair(uuid1)
+
+    <<time_low::32, time_mid::16, @uuid_v1::4, time_hi::12, rest::binary>> = ub1
+    <<time_low1::20, time_low2::12>> = <<time_low::32>>
+
+    <<time_hi::12, time_mid::16, time_low1::20, @uuid_v6::4, time_low2::12,
+      rest::binary>>
+      |> uuid_to_string(format)
+  end
+
+  @doc """
+  Convert a UUID v6 to a UUID v1 in the same format.
+
+  ## Examples
+
+      iex> UUID.uuid6_to_uuid1("1eb0d21d-afc4-631a-adc1-0242ac120002")
+      "dafc431a-0d21-11eb-adc1-0242ac120002"
+
+      iex> UUID.uuid6_to_uuid1("HrDSHa_EYxqtwQJCrBIAAg")
+      "2vxDGg0hEeutwQJCrBIAAg"
+
+      iex> UUID.uuid6_to_uuid1(<<30, 176, 210, 29, 175, 196, 99, 26, 173, 193, 2, 66, 172, 18, 0, 2>>)
+      <<218, 252, 67, 26, 13, 33, 17, 235, 173, 193, 2, 66, 172, 18, 0, 2>>
+
+  """
+  def uuid6_to_uuid1(uuid6) do
+    {format, ub6} = uuid_string_to_hex_pair(uuid6)
+
+    <<time_hi::12, time_mid::16, time_low1::20, @uuid_v6::4, time_low2::12,
+      rest::binary>> = ub6
+    <<time_low::32>> = <<time_low1::20, time_low2::12>>
+
+    <<time_low::32, time_mid::16, @uuid_v1::4, time_hi::12, rest::binary>>
+    |> uuid_to_string(format)
+  end
+
   #
   # Internal utility functions.
   #
@@ -584,6 +693,13 @@ defmodule UUID do
     <<rnd_hi::7, 1::1, rnd_low::40>>
   end
 
+  defp uuid6_node(:mac_address) do
+    uuid1_node()
+  end
+  defp uuid6_node(:random_bytes) do
+    :crypto.strong_rand_bytes(6)
+  end
+
   # Generate a hash of the given data.
   defp namebased_uuid(:md5, data) do
     md5 = :crypto.hash(:md5, data)

diff --git a/mix.lock b/mix.lock
@@ -1,8 +1,8 @@
 %{
-  "benchfella": {:hex, :benchfella, "0.3.5", "b2122c234117b3f91ed7b43b6e915e19e1ab216971154acd0a80ce0e9b8c05f5", [:mix], [], "hexpm"},
-  "earmark": {:hex, :earmark, "1.4.2", "3aa0bd23bc4c61cf2f1e5d752d1bb470560a6f8539974f767a38923bb20e1d7f", [:mix], [], "hexpm"},
-  "ex_doc": {:hex, :ex_doc, "0.21.2", "caca5bc28ed7b3bdc0b662f8afe2bee1eedb5c3cf7b322feeeb7c6ebbde089d6", [:mix], [{:earmark, "~> 1.3.3 or ~> 1.4", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm"},
-  "makeup": {:hex, :makeup, "1.0.0", "671df94cf5a594b739ce03b0d0316aa64312cee2574b6a44becb83cd90fb05dc", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.14.0", "cf8b7c66ad1cff4c14679698d532f0b5d45a3968ffbcbfd590339cb57742f1ae", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm"},
-  "nimble_parsec": {:hex, :nimble_parsec, "0.5.1", "c90796ecee0289dbb5ad16d3ad06f957b0cd1199769641c961cfe0b97db190e0", [:mix], [], "hexpm"},
+  "benchfella": {:hex, :benchfella, "0.3.5", "b2122c234117b3f91ed7b43b6e915e19e1ab216971154acd0a80ce0e9b8c05f5", [:mix], [], "hexpm", "23f27cbc482cbac03fc8926441eb60a5e111759c17642bac005c3225f5eb809d"},
+  "earmark": {:hex, :earmark, "1.4.2", "3aa0bd23bc4c61cf2f1e5d752d1bb470560a6f8539974f767a38923bb20e1d7f", [:mix], [], "hexpm", "5e8806285d8a3a8999bd38e4a73c58d28534c856bc38c44818e5ba85bbda16fb"},
+  "ex_doc": {:hex, :ex_doc, "0.21.2", "caca5bc28ed7b3bdc0b662f8afe2bee1eedb5c3cf7b322feeeb7c6ebbde089d6", [:mix], [{:earmark, "~> 1.3.3 or ~> 1.4", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "f1155337ae17ff7a1255217b4c1ceefcd1860b7ceb1a1874031e7a861b052e39"},
+  "makeup": {:hex, :makeup, "1.0.0", "671df94cf5a594b739ce03b0d0316aa64312cee2574b6a44becb83cd90fb05dc", [:mix], [{:nimble_parsec, "~> 0.5.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "a10c6eb62cca416019663129699769f0c2ccf39428b3bb3c0cb38c718a0c186d"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.14.0", "cf8b7c66ad1cff4c14679698d532f0b5d45a3968ffbcbfd590339cb57742f1ae", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "d4b316c7222a85bbaa2fd7c6e90e37e953257ad196dc229505137c5e505e9eff"},
+  "nimble_parsec": {:hex, :nimble_parsec, "0.5.1", "c90796ecee0289dbb5ad16d3ad06f957b0cd1199769641c961cfe0b97db190e0", [:mix], [], "hexpm", "00e3ebdc821fb3a36957320d49e8f4bfa310d73ea31c90e5f925dc75e030da8f"},
 }
diff --git a/test/doc_test.exs b/test/doc_test.exs
@@ -1,5 +1,5 @@
 defmodule UUID.DocTest do
   use ExUnit.Case, async: true
 
-  doctest UUID, except: [uuid1: 1, uuid1: 3, uuid4: 0, uuid4: 1, uuid4: 2]
+  doctest UUID, except: [uuid1: 1, uuid1: 3, uuid4: 0, uuid4: 1, uuid4: 2, uuid6: 2, uuid6: 3]
 end
diff --git a/test/info_tests.txt b/test/info_tests.txt
@@ -10,3 +10,6 @@ urn v4 rfc4122 || [uuid: "urn:uuid:184064df-820d-4fd2-9301-4749098cb786", binary
 default v5 rfc4122 || [uuid: "dda8df72-e4a1-5b98-a88d-8197e539c0bf", binary: <<221, 168, 223, 114, 228, 161, 91, 152, 168, 141, 129, 151, 229, 57, 192, 191>>, type: :default, version: 5, variant: :rfc4122] || dda8df72-e4a1-5b98-a88d-8197e539c0bf
 hex v5 rfc4122 || [uuid: "dda8df72e4a15b98a88d8197e539c0bf", binary: <<221, 168, 223, 114, 228, 161, 91, 152, 168, 141, 129, 151, 229, 57, 192, 191>>, type: :hex, version: 5, variant: :rfc4122] || dda8df72e4a15b98a88d8197e539c0bf
 urn v5 rfc4122 || [uuid: "urn:uuid:dda8df72-e4a1-5b98-a88d-8197e539c0bf", binary: <<221, 168, 223, 114, 228, 161, 91, 152, 168, 141, 129, 151, 229, 57, 192, 191>>, type: :urn, version: 5, variant: :rfc4122] || urn:uuid:dda8df72-e4a1-5b98-a88d-8197e539c0bf
+default v6 rfc4122 || [uuid: "1e65da3a-36e8-617e-9fcc-c8bcc8a0b17d", binary: <<30, 101, 218, 58, 54, 232, 97, 126, 159, 204, 200, 188, 200, 160, 177, 125>>, type: :default, version: 6, variant: :rfc4122] || 1e65da3a-36e8-617e-9fcc-c8bcc8a0b17d
+hex v6 rfc4122 || [uuid: "1e65da3a36e8617e9fccc8bcc8a0b17d", binary: <<30, 101, 218, 58, 54, 232, 97, 126, 159, 204, 200, 188, 200, 160, 177, 125>>, type: :hex, version: 6, variant: :rfc4122] || 1e65da3a36e8617e9fccc8bcc8a0b17d
+urn v6 rfc4122 || [uuid: "urn:uuid:1e65da3a-36e8-617e-9fcc-c8bcc8a0b17d", binary: <<30, 101, 218, 58, 54, 232, 97, 126, 159, 204, 200, 188, 200, 160, 177, 125>>, type: :urn, version: 6, variant: :rfc4122] || urn:uuid:1e65da3a-36e8-617e-9fcc-c8bcc8a0b17d
diff --git a/test/uuid_test.exs b/test/uuid_test.exs
@@ -29,6 +29,16 @@ defmodule UUIDTest do
     )
   end
 
+  test "UUID v1 to UUID v6 conversion" do
+    uuid1 = UUID.uuid1() |> validate_uuid(1)
+    assert uuid1 == UUID.uuid1_to_uuid6(uuid1) |> validate_uuid(6) |> UUID.uuid6_to_uuid1()
+  end
+
+  test "UUID v6 to UUID v1 conversion" do
+    uuid6 = UUID.uuid6() |> validate_uuid(6)
+    assert uuid6 == UUID.uuid6_to_uuid1(uuid6) |> validate_uuid(1) |> UUID.uuid1_to_uuid6()
+  end
+
   # Expand the lines in info_tests.txt into individual tests for the
   # UUID.info!/1 and UUID.info/1 functions, assuming the lines are:
   #   test name || expected output || input value
@@ -39,12 +49,18 @@ defmodule UUIDTest do
       {expected, []} = Code.eval_string(unquote(expected))
       result = UUID.info!(unquote(input))
       assert ^expected = result
+      validate_uuid(UUID.binary_to_string!(result[:binary]), expected[:version])
     end
     test "UUID.info/1 #{name}" do
       {expected, []} = Code.eval_string(unquote(expected))
       {:ok, result} = UUID.info(unquote(input))
       assert ^expected = result
+      validate_uuid(UUID.binary_to_string!(result[:binary]), expected[:version])
     end
   end
 
+  defp validate_uuid(uuid, version) when version in 1..6 do
+    assert Regex.match?(~r/^[0-9a-f]{8}-[0-9a-f]{4}-#{version}[0-9a-f]{3}-[089ab][0-9a-f]{3}-[0-9a-f]{12}$/i, uuid)
+    uuid
+  end
 end