# frozen_string_literal: true

def log_pool_size(db, previous_pool_size, current_pool_size)
  log_message = ["#{db} connection pool size: #{current_pool_size}"]

  if previous_pool_size && current_pool_size > previous_pool_size
    log_message << "(increased from #{previous_pool_size} to match thread count)"
  end

  Gitlab::AppLogger.debug(log_message.join(' '))
end

Gitlab.ee do
  # We need to initialize the Geo database before
  # setting the Geo DB connection pool size.
  if File.exist?(Rails.root.join('config/database_geo.yml'))
    Rails.application.configure do
      config.geo_database = config_for(:database_geo)
    end
  end
end

# Because of the way Ruby on Rails manages database connections, it is
# important that we have at least as many connections as we have
# threads. While there is a 'pool' setting in database.yml, it is not
# very practical because you need to maintain it in tandem with the
# number of application threads. Because of this we override the number
# of allowed connections in the database connection pool based on the
# configured number of application threads.
#
# Gitlab::Runtime.max_threads is the number of "user facing" application
# threads the process has been configured with. We also have auxiliary
# threads that use database connections. Because it is not practical to
# keep an accurate count of the number auxiliary threads as the
# application evolves over time, we just add a fixed headroom to the
# number of user-facing threads. It is OK if this number is too large
# because connections are instantiated lazily.

headroom = (ENV["DB_POOL_HEADROOM"].presence || 10).to_i
calculated_pool_size = Gitlab::Runtime.max_threads + headroom

db_config = Gitlab::Database.config ||
            Rails.application.config.database_configuration[Rails.env]

db_config['pool'] = calculated_pool_size
ActiveRecord::Base.establish_connection(db_config)

Gitlab.ee do
  if Gitlab::Runtime.sidekiq? && Gitlab::Geo.geo_database_configured?
    Rails.configuration.geo_database['pool'] = calculated_pool_size
    Geo::TrackingBase.establish_connection(Rails.configuration.geo_database)
  end
end