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defmodule Ecto.UUID do
@moduledoc """
An Ecto type for UUID strings.
use Ecto.Type
@typedoc """
A hex-encoded UUID string.
@type t :: <<_::288>>
@typedoc """
A raw binary representation of a UUID.
@type raw :: <<_::128>>
@doc false
def type, do: :uuid
@doc """
Casts to a UUID.
@spec cast(t | raw | any) :: {:ok, t} | :error
def cast(<< a1, a2, a3, a4, a5, a6, a7, a8, ?-,
b1, b2, b3, b4, ?-,
c1, c2, c3, c4, ?-,
d1, d2, d3, d4, ?-,
e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12 >>) do
<< c(a1), c(a2), c(a3), c(a4),
c(a5), c(a6), c(a7), c(a8), ?-,
c(b1), c(b2), c(b3), c(b4), ?-,
c(c1), c(c2), c(c3), c(c4), ?-,
c(d1), c(d2), c(d3), c(d4), ?-,
c(e1), c(e2), c(e3), c(e4),
c(e5), c(e6), c(e7), c(e8),
c(e9), c(e10), c(e11), c(e12) >>
:error -> :error
hex_uuid -> {:ok, hex_uuid}
def cast(<< _::128 >> = raw_uuid), do: {:ok, encode(raw_uuid)}
def cast(_), do: :error
@doc """
Same as `cast/1` but raises `Ecto.CastError` on invalid arguments.
@spec cast!(t | raw | any) :: t | no_return
def cast!(value) do
case cast(value) do
{:ok, hex_uuid} -> hex_uuid
:error -> raise Ecto.CastError, type: __MODULE__, value: value
@compile {:inline, c: 1}
defp c(?0), do: ?0
defp c(?1), do: ?1
defp c(?2), do: ?2
defp c(?3), do: ?3
defp c(?4), do: ?4
defp c(?5), do: ?5
defp c(?6), do: ?6
defp c(?7), do: ?7
defp c(?8), do: ?8
defp c(?9), do: ?9
defp c(?A), do: ?a
defp c(?B), do: ?b
defp c(?C), do: ?c
defp c(?D), do: ?d
defp c(?E), do: ?e
defp c(?F), do: ?f
defp c(?a), do: ?a
defp c(?b), do: ?b
defp c(?c), do: ?c
defp c(?d), do: ?d
defp c(?e), do: ?e
defp c(?f), do: ?f
defp c(_), do: throw(:error)
@doc """
Converts a string representing a UUID into a raw binary.
@spec dump(t | any) :: {:ok, raw} | :error
def dump(<< a1, a2, a3, a4, a5, a6, a7, a8, ?-,
b1, b2, b3, b4, ?-,
c1, c2, c3, c4, ?-,
d1, d2, d3, d4, ?-,
e1, e2, e3, e4, e5, e6, e7, e8, e9, e10, e11, e12 >>) do
<< d(a1)::4, d(a2)::4, d(a3)::4, d(a4)::4,
d(a5)::4, d(a6)::4, d(a7)::4, d(a8)::4,
d(b1)::4, d(b2)::4, d(b3)::4, d(b4)::4,
d(c1)::4, d(c2)::4, d(c3)::4, d(c4)::4,
d(d1)::4, d(d2)::4, d(d3)::4, d(d4)::4,
d(e1)::4, d(e2)::4, d(e3)::4, d(e4)::4,
d(e5)::4, d(e6)::4, d(e7)::4, d(e8)::4,
d(e9)::4, d(e10)::4, d(e11)::4, d(e12)::4 >>
:error -> :error
raw_uuid -> {:ok, raw_uuid}
def dump(_), do: :error
@compile {:inline, d: 1}
defp d(?0), do: 0
defp d(?1), do: 1
defp d(?2), do: 2
defp d(?3), do: 3
defp d(?4), do: 4
defp d(?5), do: 5
defp d(?6), do: 6
defp d(?7), do: 7
defp d(?8), do: 8
defp d(?9), do: 9
defp d(?A), do: 10
defp d(?B), do: 11
defp d(?C), do: 12
defp d(?D), do: 13
defp d(?E), do: 14
defp d(?F), do: 15
defp d(?a), do: 10
defp d(?b), do: 11
defp d(?c), do: 12
defp d(?d), do: 13
defp d(?e), do: 14
defp d(?f), do: 15
defp d(_), do: throw(:error)
@doc """
Same as `dump/1` but raises `Ecto.ArgumentError` on invalid arguments.
@spec dump!(t | any) :: raw | no_return
def dump!(value) do
case dump(value) do
{:ok, raw_uuid} -> raw_uuid
:error -> raise ArgumentError, "cannot dump given UUID to binary: #{inspect(value)}"
@doc """
Converts a binary UUID into a string.
@spec load(raw | any) :: {:ok, t} | :error | no_return
def load(<<_::128>> = raw_uuid), do: {:ok, encode(raw_uuid)}
def load(<<_::64, ?-, _::32, ?-, _::32, ?-, _::32, ?-, _::96>> = string) do
raise ArgumentError, "trying to load string UUID as Ecto.UUID: #{inspect string}. " <>
"Maybe you wanted to declare :uuid as your database field?"
def load(_), do: :error
@doc """
Same as `load/1` but raises `Ecto.ArgumentError` on invalid arguments.
@spec load!(raw | any) :: t | no_return
def load!(value) do
case load(value) do
{:ok, hex_uuid} -> hex_uuid
:error -> raise ArgumentError, "cannot load given binary as UUID: #{inspect(value)}"
@doc """
Generates a random, version 4 UUID.
@spec generate() :: t
def generate(), do: encode(bingenerate())
@doc """
Generates a random, version 4 UUID in the binary format.
@spec bingenerate() :: raw
def bingenerate() do
<<u0::48, _::4, u1::12, _::2, u2::62>> = :crypto.strong_rand_bytes(16)
<<u0::48, 4::4, u1::12, 2::2, u2::62>>
# Callback invoked by autogenerate fields.
@doc false
def autogenerate, do: generate()
@spec encode(raw) :: t
defp encode(<< a1::4, a2::4, a3::4, a4::4,
a5::4, a6::4, a7::4, a8::4,
b1::4, b2::4, b3::4, b4::4,
c1::4, c2::4, c3::4, c4::4,
d1::4, d2::4, d3::4, d4::4,
e1::4, e2::4, e3::4, e4::4,
e5::4, e6::4, e7::4, e8::4,
e9::4, e10::4, e11::4, e12::4 >>) do
<< e(a1), e(a2), e(a3), e(a4), e(a5), e(a6), e(a7), e(a8), ?-,
e(b1), e(b2), e(b3), e(b4), ?-,
e(c1), e(c2), e(c3), e(c4), ?-,
e(d1), e(d2), e(d3), e(d4), ?-,
e(e1), e(e2), e(e3), e(e4), e(e5), e(e6), e(e7), e(e8), e(e9), e(e10), e(e11), e(e12) >>
@compile {:inline, e: 1}
defp e(0), do: ?0
defp e(1), do: ?1
defp e(2), do: ?2
defp e(3), do: ?3
defp e(4), do: ?4
defp e(5), do: ?5
defp e(6), do: ?6
defp e(7), do: ?7
defp e(8), do: ?8
defp e(9), do: ?9
defp e(10), do: ?a
defp e(11), do: ?b
defp e(12), do: ?c
defp e(13), do: ?d
defp e(14), do: ?e
defp e(15), do: ?f