diff options
Diffstat (limited to 'lib/pleroma/flake_id.ex')
-rw-r--r-- | lib/pleroma/flake_id.ex | 182 |
1 files changed, 0 insertions, 182 deletions
diff --git a/lib/pleroma/flake_id.ex b/lib/pleroma/flake_id.ex deleted file mode 100644 index 042cf8659..000000000 --- a/lib/pleroma/flake_id.ex +++ /dev/null @@ -1,182 +0,0 @@ -# Pleroma: A lightweight social networking server -# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/> -# SPDX-License-Identifier: AGPL-3.0-only - -defmodule Pleroma.FlakeId do - @moduledoc """ - Flake is a decentralized, k-ordered id generation service. - - Adapted from: - - * [flaky](https://github.com/nirvana/flaky), released under the terms of the Truly Free License, - * [Flake](https://github.com/boundary/flake), Copyright 2012, Boundary, Apache License, Version 2.0 - """ - - @type t :: binary - - use Ecto.Type - use GenServer - require Logger - alias __MODULE__ - import Kernel, except: [to_string: 1] - - defstruct node: nil, time: 0, sq: 0 - - @doc "Converts a binary Flake to a String" - def to_string(<<0::integer-size(64), id::integer-size(64)>>) do - Kernel.to_string(id) - end - - def to_string(<<_::integer-size(64), _::integer-size(48), _::integer-size(16)>> = flake) do - encode_base62(flake) - end - - def to_string(s), do: s - - def from_string(int) when is_integer(int) do - from_string(Kernel.to_string(int)) - end - - for i <- [-1, 0] do - def from_string(unquote(i)), do: <<0::integer-size(128)>> - def from_string(unquote(Kernel.to_string(i))), do: <<0::integer-size(128)>> - end - - def from_string(<<_::integer-size(128)>> = flake), do: flake - - def from_string(string) when is_binary(string) and byte_size(string) < 18 do - case Integer.parse(string) do - {id, ""} -> <<0::integer-size(64), id::integer-size(64)>> - _ -> nil - end - end - - def from_string(string) do - string |> decode_base62 |> from_integer - end - - def to_integer(<<integer::integer-size(128)>>), do: integer - - def from_integer(integer) do - <<_time::integer-size(64), _node::integer-size(48), _seq::integer-size(16)>> = - <<integer::integer-size(128)>> - end - - @doc "Generates a Flake" - @spec get :: binary - def get, do: to_string(:gen_server.call(:flake, :get)) - - # checks that ID is is valid FlakeID - # - @spec is_flake_id?(String.t()) :: boolean - def is_flake_id?(id), do: is_flake_id?(String.to_charlist(id), true) - defp is_flake_id?([c | cs], true) when c >= ?0 and c <= ?9, do: is_flake_id?(cs, true) - defp is_flake_id?([c | cs], true) when c >= ?A and c <= ?Z, do: is_flake_id?(cs, true) - defp is_flake_id?([c | cs], true) when c >= ?a and c <= ?z, do: is_flake_id?(cs, true) - defp is_flake_id?([], true), do: true - defp is_flake_id?(_, _), do: false - - # -- Ecto.Type API - @impl Ecto.Type - def type, do: :uuid - - @impl Ecto.Type - def cast(value) do - {:ok, FlakeId.to_string(value)} - end - - @impl Ecto.Type - def load(value) do - {:ok, FlakeId.to_string(value)} - end - - @impl Ecto.Type - def dump(value) do - {:ok, FlakeId.from_string(value)} - end - - def autogenerate, do: get() - - # -- GenServer API - def start_link(_) do - :gen_server.start_link({:local, :flake}, __MODULE__, [], []) - end - - @impl GenServer - def init([]) do - {:ok, %FlakeId{node: worker_id(), time: time()}} - end - - @impl GenServer - def handle_call(:get, _from, state) do - {flake, new_state} = get(time(), state) - {:reply, flake, new_state} - end - - # Matches when the calling time is the same as the state time. Incr. sq - defp get(time, %FlakeId{time: time, node: node, sq: seq}) do - new_state = %FlakeId{time: time, node: node, sq: seq + 1} - {gen_flake(new_state), new_state} - end - - # Matches when the times are different, reset sq - defp get(newtime, %FlakeId{time: time, node: node}) when newtime > time do - new_state = %FlakeId{time: newtime, node: node, sq: 0} - {gen_flake(new_state), new_state} - end - - # Error when clock is running backwards - defp get(newtime, %FlakeId{time: time}) when newtime < time do - {:error, :clock_running_backwards} - end - - defp gen_flake(%FlakeId{time: time, node: node, sq: seq}) do - <<time::integer-size(64), node::integer-size(48), seq::integer-size(16)>> - end - - defp nthchar_base62(n) when n <= 9, do: ?0 + n - defp nthchar_base62(n) when n <= 35, do: ?A + n - 10 - defp nthchar_base62(n), do: ?a + n - 36 - - defp encode_base62(<<integer::integer-size(128)>>) do - integer - |> encode_base62([]) - |> List.to_string() - end - - defp encode_base62(int, acc) when int < 0, do: encode_base62(-int, acc) - defp encode_base62(int, []) when int == 0, do: '0' - defp encode_base62(int, acc) when int == 0, do: acc - - defp encode_base62(int, acc) do - r = rem(int, 62) - id = div(int, 62) - acc = [nthchar_base62(r) | acc] - encode_base62(id, acc) - end - - defp decode_base62(s) do - decode_base62(String.to_charlist(s), 0) - end - - defp decode_base62([c | cs], acc) when c >= ?0 and c <= ?9, - do: decode_base62(cs, 62 * acc + (c - ?0)) - - defp decode_base62([c | cs], acc) when c >= ?A and c <= ?Z, - do: decode_base62(cs, 62 * acc + (c - ?A + 10)) - - defp decode_base62([c | cs], acc) when c >= ?a and c <= ?z, - do: decode_base62(cs, 62 * acc + (c - ?a + 36)) - - defp decode_base62([], acc), do: acc - - defp time do - {mega_seconds, seconds, micro_seconds} = :erlang.timestamp() - 1_000_000_000 * mega_seconds + seconds * 1000 + :erlang.trunc(micro_seconds / 1000) - end - - defp worker_id do - <<worker::integer-size(48)>> = :crypto.strong_rand_bytes(6) - worker - end -end |