# Pleroma: A lightweight social networking server # Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.Migrators.Support.BaseMigrator do @moduledoc """ Base background migrator functionality. """ @callback perform() :: any() @callback retry_failed() :: any() @callback feature_config_path() :: list(atom()) @callback query() :: Ecto.Query.t() @callback fault_rate_allowance() :: integer() | float() defmacro __using__(_opts) do quote do use GenServer require Logger import Ecto.Query alias __MODULE__.State alias Pleroma.Config alias Pleroma.Repo @behaviour Pleroma.Migrators.Support.BaseMigrator defdelegate data_migration(), to: State defdelegate data_migration_id(), to: State defdelegate state(), to: State defdelegate persist_state(), to: State, as: :persist_to_db defdelegate get_stat(key, value \\ nil), to: State, as: :get_data_key defdelegate put_stat(key, value), to: State, as: :put_data_key defdelegate increment_stat(key, increment), to: State, as: :increment_data_key @reg_name {:global, __MODULE__} def whereis, do: GenServer.whereis(@reg_name) def start_link(_) do case whereis() do nil -> GenServer.start_link(__MODULE__, nil, name: @reg_name) pid -> {:ok, pid} end end @impl true def init(_) do {:ok, nil, {:continue, :init_state}} end @impl true def handle_continue(:init_state, _state) do {:ok, _} = State.start_link(nil) data_migration = data_migration() manual_migrations = Config.get([:instance, :manual_data_migrations], []) cond do Config.get(:env) == :test -> update_status(:noop) is_nil(data_migration) -> message = "Data migration does not exist." update_status(:failed, message) Logger.error("#{__MODULE__}: #{message}") data_migration.state == :manual or data_migration.name in manual_migrations -> message = "Data migration is in manual execution or manual fix mode." update_status(:manual, message) Logger.warn("#{__MODULE__}: #{message}") data_migration.state == :complete -> on_complete(data_migration) true -> send(self(), :perform) end {:noreply, nil} end @impl true def handle_info(:perform, state) do State.reinit() update_status(:running) put_stat(:iteration_processed_count, 0) put_stat(:started_at, NaiveDateTime.utc_now()) perform() fault_rate = fault_rate() put_stat(:fault_rate, fault_rate) fault_rate_allowance = fault_rate_allowance() cond do fault_rate == 0 -> set_complete() is_float(fault_rate) and fault_rate <= fault_rate_allowance -> message = """ Done with fault rate of #{fault_rate} which doesn't exceed #{fault_rate_allowance}. Putting data migration to manual fix mode. Try running `#{__MODULE__}.retry_failed/0`. """ Logger.warn("#{__MODULE__}: #{message}") update_status(:manual, message) on_complete(data_migration()) true -> message = "Too many failures. Try running `#{__MODULE__}.retry_failed/0`." Logger.error("#{__MODULE__}: #{message}") update_status(:failed, message) end persist_state() {:noreply, state} end defp on_complete(data_migration) do if data_migration.feature_lock || feature_state() == :disabled do Logger.warn( "#{__MODULE__}: migration complete but feature is locked; consider enabling." ) :noop else Config.put(feature_config_path(), :enabled) :ok end end @doc "Approximate count for current iteration (including processed records count)" def count(force \\ false, timeout \\ :infinity) do stored_count = get_stat(:count) if stored_count && !force do stored_count else processed_count = get_stat(:processed_count, 0) max_processed_id = get_stat(:max_processed_id, 0) query = where(query(), [entity], entity.id > ^max_processed_id) count = Repo.aggregate(query, :count, :id, timeout: timeout) + processed_count put_stat(:count, count) persist_state() count end end def failures_count do with {:ok, %{rows: [[count]]}} <- Repo.query( "SELECT COUNT(record_id) FROM data_migration_failed_ids WHERE data_migration_id = $1;", [data_migration_id()] ) do count end end def feature_state, do: Config.get(feature_config_path()) def force_continue do send(whereis(), :perform) end def force_restart do :ok = State.reset() force_continue() end def set_complete do update_status(:complete) persist_state() on_complete(data_migration()) end defp update_status(status, message \\ nil) do put_stat(:state, status) put_stat(:message, message) end defp fault_rate do with failures_count when is_integer(failures_count) <- failures_count() do failures_count / Enum.max([get_stat(:affected_count, 0), 1]) else _ -> :error end end defp records_per_second do get_stat(:iteration_processed_count, 0) / Enum.max([running_time(), 1]) end defp running_time do NaiveDateTime.diff( NaiveDateTime.utc_now(), get_stat(:started_at, NaiveDateTime.utc_now()) ) end end end end