gitlab-org--gitlab-foss/lib/gitlab/utils/strong_memoize.rb

59 lines
1.4 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Utils
module StrongMemoize
# Instead of writing patterns like this:
#
# def trigger_from_token
# return @trigger if defined?(@trigger)
#
# @trigger = Ci::Trigger.find_by_token(params[:token].to_s)
# end
#
# We could write it like:
#
# include Gitlab::Utils::StrongMemoize
#
# def trigger_from_token
# strong_memoize(:trigger) do
# Ci::Trigger.find_by_token(params[:token].to_s)
# end
# end
#
def strong_memoize(name)
key = ivar(name)
if instance_variable_defined?(key)
instance_variable_get(key)
else
instance_variable_set(key, yield)
end
end
def strong_memoized?(name)
instance_variable_defined?(ivar(name))
end
def clear_memoization(name)
key = ivar(name)
remove_instance_variable(key) if instance_variable_defined?(key)
end
private
# Convert `"name"`/`:name` into `:@name`
#
# Depending on a type ensure that there's a single memory allocation
def ivar(name)
if name.is_a?(Symbol)
name.to_s.prepend("@").to_sym
elsif name.is_a?(String)
:"@#{name}"
else
raise ArgumentError, "Invalid type of '#{name}'"
end
end
end
end
end