akkoma/lib/pleroma/migrators/context_objects_deletion_migrator.ex
Hélène 88c1c76d3e
Migrations: delete contexts with BaseMigrator
Due to the lengthiness of this task, the migration has been adapted into
a BaseMigrator migration, running in the background instead.
2022-08-15 01:47:09 +02:00

139 lines
4.1 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Migrators.ContextObjectsDeletionMigrator do
defmodule State do
use Pleroma.Migrators.Support.BaseMigratorState
@impl Pleroma.Migrators.Support.BaseMigratorState
defdelegate data_migration(), to: Pleroma.DataMigration, as: :delete_context_objects
end
use Pleroma.Migrators.Support.BaseMigrator
alias Pleroma.Migrators.Support.BaseMigrator
alias Pleroma.Object
@doc "This migration removes objects created exclusively for contexts, containing only an `id` field."
@impl BaseMigrator
def feature_config_path, do: [:features, :delete_context_objects]
@impl BaseMigrator
def fault_rate_allowance, do: Config.get([:delete_context_objects, :fault_rate_allowance], 0)
@impl BaseMigrator
def perform do
data_migration_id = data_migration_id()
max_processed_id = get_stat(:max_processed_id, 0)
Logger.info("Deleting context objects from `objects` (from oid: #{max_processed_id})...")
query()
|> where([object], object.id > ^max_processed_id)
|> Repo.chunk_stream(100, :batches, timeout: :infinity)
|> Stream.each(fn objects ->
object_ids = Enum.map(objects, & &1.id)
results = Enum.map(object_ids, &delete_context_object(&1))
failed_ids =
results
|> Enum.filter(&(elem(&1, 0) == :error))
|> Enum.map(&elem(&1, 1))
chunk_affected_count =
results
|> Enum.filter(&(elem(&1, 0) == :ok))
|> length()
for failed_id <- failed_ids do
_ =
Repo.query(
"INSERT INTO data_migration_failed_ids(data_migration_id, record_id) " <>
"VALUES ($1, $2) ON CONFLICT DO NOTHING;",
[data_migration_id, failed_id]
)
end
_ =
Repo.query(
"DELETE FROM data_migration_failed_ids " <>
"WHERE data_migration_id = $1 AND record_id = ANY($2)",
[data_migration_id, object_ids -- failed_ids]
)
max_object_id = Enum.at(object_ids, -1)
put_stat(:max_processed_id, max_object_id)
increment_stat(:iteration_processed_count, length(object_ids))
increment_stat(:processed_count, length(object_ids))
increment_stat(:failed_count, length(failed_ids))
increment_stat(:affected_count, chunk_affected_count)
put_stat(:records_per_second, records_per_second())
persist_state()
# A quick and dirty approach to controlling the load this background migration imposes
sleep_interval = Config.get([:delete_context_objects, :sleep_interval_ms], 0)
Process.sleep(sleep_interval)
end)
|> Stream.run()
end
@impl BaseMigrator
def query do
# Context objects have no activity type, and only one field, `id`.
# Only those context objects are without types.
from(
object in Object,
where: fragment("(?)->'type' IS NULL", object.data),
select: %{
id: object.id
}
)
end
@spec delete_context_object(integer()) :: {:ok | :error, integer()}
defp delete_context_object(id) do
result =
%Object{id: id}
|> Repo.delete()
|> elem(0)
{result, id}
end
@impl BaseMigrator
def retry_failed do
data_migration_id = data_migration_id()
failed_objects_query()
|> Repo.chunk_stream(100, :one)
|> Stream.each(fn object ->
with {res, _} when res != :error <- delete_context_object(object.id) do
_ =
Repo.query(
"DELETE FROM data_migration_failed_ids " <>
"WHERE data_migration_id = $1 AND record_id = $2",
[data_migration_id, object.id]
)
end
end)
|> Stream.run()
put_stat(:failed_count, failures_count())
persist_state()
force_continue()
end
defp failed_objects_query do
from(o in Object)
|> join(:inner, [o], dmf in fragment("SELECT * FROM data_migration_failed_ids"),
on: dmf.record_id == o.id
)
|> where([_o, dmf], dmf.data_migration_id == ^data_migration_id())
|> order_by([o], asc: o.id)
end
end