mastodon/lib/tasks/db.rake

# frozen_string_literal: true

require_relative '../mastodon/snowflake'

def each_schema_load_environment
  # If we're in development, also run this for the test environment.
  # This is a somewhat hacky way to do this, so here's why:
  # 1. We have to define this before we load the schema, or we won't
  #    have a timestamp_id function when we get to it in the schema.
  # 2. db:setup calls db:schema:load_if_ruby, which calls
  #    db:schema:load, which we define above as having a prerequisite
  #    of this task.
  # 3. db:schema:load ends up running
  #    ActiveRecord::Tasks::DatabaseTasks.load_schema_current, which
  #    calls a private method `each_current_configuration`, which
  #    explicitly also does the loading for the `test` environment
  #    if the current environment is `development`, so we end up
  #    needing to do the same, and we can't even use the same method
  #    to do it.

  if Rails.env.development?
    test_conf = ActiveRecord::Base.configurations['test']

    if test_conf['database']&.present?
      ActiveRecord::Base.establish_connection(:test)
      yield
      ActiveRecord::Base.establish_connection(Rails.env.to_sym)
    end
  end

  yield
end

namespace :db do
  namespace :migrate do
    desc 'Setup the db or migrate depending on state of db'
    task setup: :environment do
      begin
        if ActiveRecord::Migrator.current_version.zero?
          Rake::Task['db:migrate'].invoke
          Rake::Task['db:seed'].invoke
        end
      rescue ActiveRecord::NoDatabaseError
        Rake::Task['db:setup'].invoke
      else
        Rake::Task['db:migrate'].invoke
      end
    end
  end

  task :post_migration_hook do
    at_exit do
      unless %w(C POSIX).include?(ActiveRecord::Base.connection.execute('SELECT datcollate FROM pg_database WHERE datname = current_database();').first['datcollate'])
        warn <<~WARNING
          Your database collation is susceptible to index corruption.
            (This warning does not indicate that index corruption has occured and can be ignored)
            (To learn more, visit: https://docs.joinmastodon.org/admin/troubleshooting/index-corruption/)
        WARNING
      end
    end
  end

  Rake::Task['db:migrate'].enhance(['db:post_migration_hook'])

  # Before we load the schema, define the timestamp_id function.
  # Idiomatically, we might do this in a migration, but then it
  # wouldn't end up in schema.rb, so we'd need to figure out a way to
  # get it in before doing db:setup as well. This is simpler, and
  # ensures it's always in place.
  Rake::Task['db:schema:load'].enhance ['db:define_timestamp_id']

  # After we load the schema, make sure we have sequences for each
  # table using timestamp IDs.
  Rake::Task['db:schema:load'].enhance do
    Rake::Task['db:ensure_id_sequences_exist'].invoke
  end

  task :define_timestamp_id do
    each_schema_load_environment do
      Mastodon::Snowflake.define_timestamp_id
    end
  end

  task :ensure_id_sequences_exist do
    each_schema_load_environment do
      Mastodon::Snowflake.ensure_id_sequences_exist
    end
  end
end