From 44b484de216343beb373bef68fa52102537ccf12 Mon Sep 17 00:00:00 2001
From: miraikumiko <miraikumiko@disroot.org>
Date: Fri, 13 Jun 2025 15:10:17 +0200
Subject: [PATCH] Add snowflake IDs

---
 config/config.exs                             |  4 ++
 lib/nulla/application.ex                      |  5 +-
 lib/nulla/models/activity.ex                  |  1 +
 lib/nulla/models/bookmarks.ex                 |  1 +
 lib/nulla/models/follow.ex                    |  1 +
 lib/nulla/models/hashtag.ex                   |  1 +
 lib/nulla/models/media_attachment.ex          |  1 +
 lib/nulla/models/moderation_log.ex            |  1 +
 lib/nulla/models/note.ex                      |  1 +
 lib/nulla/models/notification.ex              |  1 +
 lib/nulla/models/session.ex                   |  1 +
 lib/nulla/models/user.ex                      | 11 ++++
 lib/nulla/snowflake.ex                        | 62 +++++++++++++++++++
 ...0250527054942_create_instance_settings.exs |  9 ++-
 .../20250530110822_create_users.exs           |  3 +-
 .../20250604083506_create_notes.exs           |  3 +-
 .../20250606100445_create_bookmarks.exs       |  3 +-
 .../20250606103230_create_notifications.exs   |  3 +-
 ...20250606103527_create_moderations_logs.exs |  3 +-
 .../20250606103649_create_hashtags.exs        |  3 +-
 .../20250606103707_create_follows.exs         |  3 +-
 .../20250606131715_create_sessions.exs        |  3 +-
 ...0250606132108_create_media_attachments.exs |  3 +-
 .../20250607124601_create_activities.exs      |  3 +-
 24 files changed, 116 insertions(+), 14 deletions(-)
 create mode 100644 lib/nulla/snowflake.ex

diff --git a/config/config.exs b/config/config.exs
index 2c52b8a..fc9357b 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -22,6 +22,10 @@ config :nulla, NullaWeb.Endpoint,
   pubsub_server: Nulla.PubSub,
   live_view: [signing_salt: "jcAt5/U+"]
 
+# Snowflake configuration
+config :nulla, :snowflake,
+  worker_id: 1
+
 # Configures the mailer
 #
 # By default it uses the "Local" adapter which stores the emails
diff --git a/lib/nulla/application.ex b/lib/nulla/application.ex
index 7e86858..6832652 100644
--- a/lib/nulla/application.ex
+++ b/lib/nulla/application.ex
@@ -7,6 +7,8 @@ defmodule Nulla.Application do
 
   @impl true
   def start(_type, _args) do
+    worker_id = Application.fetch_env!(:nulla, :snowflake)[:worker_id]
+
     children = [
       NullaWeb.Telemetry,
       Nulla.Repo,
@@ -17,7 +19,8 @@ defmodule Nulla.Application do
       # Start a worker by calling: Nulla.Worker.start_link(arg)
       # {Nulla.Worker, arg},
       # Start to serve requests, typically the last entry
-      NullaWeb.Endpoint
+      NullaWeb.Endpoint,
+      {Nulla.Snowflake, worker_id}
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html
diff --git a/lib/nulla/models/activity.ex b/lib/nulla/models/activity.ex
index bf0101e..e41b879 100644
--- a/lib/nulla/models/activity.ex
+++ b/lib/nulla/models/activity.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.Activity do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "activities" do
     field :type, :string
     field :actor, :string
diff --git a/lib/nulla/models/bookmarks.ex b/lib/nulla/models/bookmarks.ex
index b4e7a5b..1688167 100644
--- a/lib/nulla/models/bookmarks.ex
+++ b/lib/nulla/models/bookmarks.ex
@@ -5,6 +5,7 @@ defmodule Nulla.Models.Bookmark do
   alias Nulla.Repo
   alias Nulla.Models.Bookmark
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "bookmarks" do
     field :url, :string
     field :user_id, :id
diff --git a/lib/nulla/models/follow.ex b/lib/nulla/models/follow.ex
index 0469dbd..3646881 100644
--- a/lib/nulla/models/follow.ex
+++ b/lib/nulla/models/follow.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.Follow do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "follows" do
     belongs_to :user, Nulla.Models.User
     belongs_to :target, Nulla.Models.User
diff --git a/lib/nulla/models/hashtag.ex b/lib/nulla/models/hashtag.ex
index 0be647d..5e6d71e 100644
--- a/lib/nulla/models/hashtag.ex
+++ b/lib/nulla/models/hashtag.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.Hashtag do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "hashtags" do
     field :tag, :string
     field :usage_count, :integer, default: 0
diff --git a/lib/nulla/models/media_attachment.ex b/lib/nulla/models/media_attachment.ex
index 9eca245..bafed6f 100644
--- a/lib/nulla/models/media_attachment.ex
+++ b/lib/nulla/models/media_attachment.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.MediaAttachment do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "media_attachments" do
     field :file, :string
     field :mime_type, :string
diff --git a/lib/nulla/models/moderation_log.ex b/lib/nulla/models/moderation_log.ex
index f6d3469..7e30af1 100644
--- a/lib/nulla/models/moderation_log.ex
+++ b/lib/nulla/models/moderation_log.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.ModerationLog do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "moderation_logs" do
     field :target_type, :string
     field :target_id, :string
diff --git a/lib/nulla/models/note.ex b/lib/nulla/models/note.ex
index 57a07e6..efaf328 100644
--- a/lib/nulla/models/note.ex
+++ b/lib/nulla/models/note.ex
@@ -5,6 +5,7 @@ defmodule Nulla.Models.Note do
   alias Nulla.Repo
   alias Nulla.Models.Note
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "notes" do
     field :content, :string
 
diff --git a/lib/nulla/models/notification.ex b/lib/nulla/models/notification.ex
index c0d595c..946f58b 100644
--- a/lib/nulla/models/notification.ex
+++ b/lib/nulla/models/notification.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.Notification do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "notifications" do
     field :type, :string
     field :data, :map
diff --git a/lib/nulla/models/session.ex b/lib/nulla/models/session.ex
index c505ad6..0eb45b7 100644
--- a/lib/nulla/models/session.ex
+++ b/lib/nulla/models/session.ex
@@ -2,6 +2,7 @@ defmodule Nulla.Models.Session do
   use Ecto.Schema
   import Ecto.Changeset
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "sessions" do
     field :token, :string
     field :user_agent, :string
diff --git a/lib/nulla/models/user.ex b/lib/nulla/models/user.ex
index caf90c5..b3ef7ce 100644
--- a/lib/nulla/models/user.ex
+++ b/lib/nulla/models/user.ex
@@ -2,8 +2,10 @@ defmodule Nulla.Models.User do
   use Ecto.Schema
   import Ecto.Changeset
   alias Nulla.Repo
+  alias Nulla.Snowflake
   alias Nulla.Models.User
 
+  @primary_key {:id, :integer, autogenerate: false}
   schema "users" do
     field :username, :string
     field :email, :string
@@ -77,6 +79,15 @@ defmodule Nulla.Models.User do
     ])
   end
 
+  def create_user(attrs) do
+    id = Snowflake.next_id()
+
+    %User{}
+    |> User.changeset(attrs)
+    |> Ecto.Changeset.put_change(:id, id)
+    |> Repo.insert()
+  end
+
   def get_user_by_username(username), do: Repo.get_by(User, username: username)
 
   def get_user_by_username!(username), do: Repo.get_by!(User, username: username)
diff --git a/lib/nulla/snowflake.ex b/lib/nulla/snowflake.ex
new file mode 100644
index 0000000..5b7c88e
--- /dev/null
+++ b/lib/nulla/snowflake.ex
@@ -0,0 +1,62 @@
+defmodule Nulla.Snowflake do
+  use GenServer
+  import Bitwise
+
+  @epoch :calendar.datetime_to_gregorian_seconds({{2020, 1, 1}, {0, 0, 0}}) * 1000
+  @max_sequence 4095
+  @time_shift 22
+  @worker_shift 12
+
+  def start_link(worker_id) when worker_id in 0..1023 do
+    GenServer.start_link(__MODULE__, worker_id, name: __MODULE__)
+  end
+
+  def next_id do
+    GenServer.call(__MODULE__, :next_id)
+  end
+
+  @impl true
+  def init(worker_id) do
+    {:ok, %{last_timestamp: -1, sequence: 0, worker_id: worker_id}}
+  end
+
+  @impl true
+  def handle_call(:next_id, _from, %{worker_id: worker_id} = state) do
+    timestamp = current_time()
+
+    {timestamp, sequence, state} =
+      cond do
+        timestamp < state.last_timestamp ->
+          raise "Clock moved backwards"
+
+        timestamp == state.last_timestamp and state.sequence < @max_sequence ->
+          {timestamp, state.sequence + 1, %{state | sequence: state.sequence + 1}}
+
+        timestamp == state.last_timestamp ->
+          wait_for_next_millisecond(timestamp)
+          new_timestamp = current_time()
+          {new_timestamp, 0, %{state | last_timestamp: new_timestamp, sequence: 0}}
+
+        true ->
+          {timestamp, 0, %{state | last_timestamp: timestamp, sequence: 0}}
+      end
+
+    raw_id =
+      ((timestamp - @epoch) <<< @time_shift)
+      |> bor(worker_id <<< @worker_shift)
+      |> bor(sequence)
+
+    id = Bitwise.band(raw_id, 0x7FFFFFFFFFFFFFFF)
+
+    {:reply, id, %{state | last_timestamp: timestamp, sequence: sequence}}
+  end
+
+  defp current_time do
+    System.system_time(:millisecond)
+  end
+
+  defp wait_for_next_millisecond(last_ts) do
+    :timer.sleep(1)
+    if current_time() <= last_ts, do: wait_for_next_millisecond(last_ts), else: :ok
+  end
+end
diff --git a/priv/repo/migrations/20250527054942_create_instance_settings.exs b/priv/repo/migrations/20250527054942_create_instance_settings.exs
index 3f8be91..64c45f0 100644
--- a/priv/repo/migrations/20250527054942_create_instance_settings.exs
+++ b/priv/repo/migrations/20250527054942_create_instance_settings.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
   use Ecto.Migration
 
   def change do
-    create table(:instance_settings) do
+    create table(:instance_settings, primary_key: false) do
+      add :id, :integer, primary_key: true
       add :name, :string, default: "Nulla", null: false
       add :description, :text, default: "Freedom Social Network", null: false
       add :domain, :string, default: "localhost", null: false
@@ -16,6 +17,8 @@ defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
       timestamps()
     end
 
+    execute "ALTER TABLE instance_settings ADD CONSTRAINT single_row CHECK (id = 1);"
+
     flush()
 
     execute(fn ->
@@ -31,11 +34,11 @@ defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
 
       sql = """
       INSERT INTO instance_settings (
-        name, description, domain, registration,
+        id, name, description, domain, registration,
         max_characters, max_upload_size, api_offset,
         public_key, private_key, inserted_at, updated_at
       ) VALUES (
-        'Nulla', 'Freedom Social Network', '#{domain}', false,
+        1, 'Nulla', 'Freedom Social Network', '#{domain}', false,
         5000, 50, 100,
         #{esc.(public_key)}, #{esc.(private_key)},
         '#{now}', '#{now}'
diff --git a/priv/repo/migrations/20250530110822_create_users.exs b/priv/repo/migrations/20250530110822_create_users.exs
index cc7ab33..b597c2f 100644
--- a/priv/repo/migrations/20250530110822_create_users.exs
+++ b/priv/repo/migrations/20250530110822_create_users.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateUsers do
   use Ecto.Migration
 
   def change do
-    create table(:users) do
+    create table(:users, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :username, :string, null: false, unique: true
       add :email, :string
       add :password, :string
diff --git a/priv/repo/migrations/20250604083506_create_notes.exs b/priv/repo/migrations/20250604083506_create_notes.exs
index e14f519..975fd6f 100644
--- a/priv/repo/migrations/20250604083506_create_notes.exs
+++ b/priv/repo/migrations/20250604083506_create_notes.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateNotes do
   use Ecto.Migration
 
   def change do
-    create table(:notes) do
+    create table(:notes, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :content, :text
       add :visibility, :string, default: "public"
       add :sensitive, :boolean, default: false
diff --git a/priv/repo/migrations/20250606100445_create_bookmarks.exs b/priv/repo/migrations/20250606100445_create_bookmarks.exs
index 810721e..5ddb447 100644
--- a/priv/repo/migrations/20250606100445_create_bookmarks.exs
+++ b/priv/repo/migrations/20250606100445_create_bookmarks.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateBookmarks do
   use Ecto.Migration
 
   def change do
-    create table(:bookmarks) do
+    create table(:bookmarks, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :url, :string
       add :user_id, references(:users, on_delete: :delete_all)
 
diff --git a/priv/repo/migrations/20250606103230_create_notifications.exs b/priv/repo/migrations/20250606103230_create_notifications.exs
index 85ec848..ec8cbc0 100644
--- a/priv/repo/migrations/20250606103230_create_notifications.exs
+++ b/priv/repo/migrations/20250606103230_create_notifications.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateNotifications do
   use Ecto.Migration
 
   def change do
-    create table(:notifications) do
+    create table(:notifications, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :user_id, references(:users, on_delete: :delete_all), null: false
       add :actor_id, references(:users, on_delete: :nilify_all)
       add :type, :string, null: false
diff --git a/priv/repo/migrations/20250606103527_create_moderations_logs.exs b/priv/repo/migrations/20250606103527_create_moderations_logs.exs
index 252231f..546f88e 100644
--- a/priv/repo/migrations/20250606103527_create_moderations_logs.exs
+++ b/priv/repo/migrations/20250606103527_create_moderations_logs.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateModerationLogs do
   use Ecto.Migration
 
   def change do
-    create table(:moderation_logs) do
+    create table(:moderation_logs, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :moderator_id, references(:users, on_delete: :nilify_all), null: false
       add :target_type, :string, null: false
       add :target_id, :string, null: false
diff --git a/priv/repo/migrations/20250606103649_create_hashtags.exs b/priv/repo/migrations/20250606103649_create_hashtags.exs
index 6a155cc..ac94cb2 100644
--- a/priv/repo/migrations/20250606103649_create_hashtags.exs
+++ b/priv/repo/migrations/20250606103649_create_hashtags.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateHashtags do
   use Ecto.Migration
 
   def change do
-    create table(:hashtags) do
+    create table(:hashtags, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :tag, :string, null: false
       add :usage_count, :integer, default: 0, null: false
 
diff --git a/priv/repo/migrations/20250606103707_create_follows.exs b/priv/repo/migrations/20250606103707_create_follows.exs
index 27f161f..b39244e 100644
--- a/priv/repo/migrations/20250606103707_create_follows.exs
+++ b/priv/repo/migrations/20250606103707_create_follows.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateFollows do
   use Ecto.Migration
 
   def change do
-    create table(:follows) do
+    create table(:follows, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :user_id, references(:users, on_delete: :delete_all), null: false
       add :target_id, references(:users, on_delete: :delete_all), null: false
 
diff --git a/priv/repo/migrations/20250606131715_create_sessions.exs b/priv/repo/migrations/20250606131715_create_sessions.exs
index b11c9fc..3e0e9e2 100644
--- a/priv/repo/migrations/20250606131715_create_sessions.exs
+++ b/priv/repo/migrations/20250606131715_create_sessions.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateSessions do
   use Ecto.Migration
 
   def change do
-    create table(:sessions) do
+    create table(:sessions, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :user_id, references(:users, on_delete: :delete_all), null: false
       add :token, :string, null: false
       add :user_agent, :string
diff --git a/priv/repo/migrations/20250606132108_create_media_attachments.exs b/priv/repo/migrations/20250606132108_create_media_attachments.exs
index 0aef7bd..1d9fe64 100644
--- a/priv/repo/migrations/20250606132108_create_media_attachments.exs
+++ b/priv/repo/migrations/20250606132108_create_media_attachments.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateMediaAttachments do
   use Ecto.Migration
 
   def change do
-    create table(:media_attachments) do
+    create table(:media_attachments, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :note_id, references(:notes, on_delete: :delete_all), null: false
       add :file, :string, null: false
       add :mime_type, :string
diff --git a/priv/repo/migrations/20250607124601_create_activities.exs b/priv/repo/migrations/20250607124601_create_activities.exs
index 0ed3cf2..25addfd 100644
--- a/priv/repo/migrations/20250607124601_create_activities.exs
+++ b/priv/repo/migrations/20250607124601_create_activities.exs
@@ -2,7 +2,8 @@ defmodule Nulla.Repo.Migrations.CreateActivities do
   use Ecto.Migration
 
   def change do
-    create table(:activities) do
+    create table(:activities, primary_key: false) do
+      add :id, :bigint, primary_key: true
       add :type, :string, null: false
       add :actor, :string, null: false
       add :object, :map, null: false