cacheable_attributes.rb 1.82 KB
Newer Older
1 2
# frozen_string_literal: true

3 4 5 6 7 8 9 10
module CacheableAttributes
  extend ActiveSupport::Concern

  included do
    after_commit { self.class.expire }
  end

  class_methods do
11
    def cache_key
12
      "#{name}:#{Gitlab::VERSION}:#{Rails.version}".freeze
13 14
    end

15
    # Can be overridden
16 17 18 19
    def current_without_cache
      last
    end

20
    # Can be overridden
21 22 23 24 25
    def defaults
      {}
    end

    def build_from_defaults(attributes = {})
26 27 28 29 30 31
      final_attributes = defaults
        .merge(attributes)
        .stringify_keys
        .slice(*column_names)

      new(final_attributes)
32 33 34
    end

    def cached
35
      Gitlab::SafeRequestStore[:"#{name}_cached_attributes"] ||= retrieve_from_cache
36 37 38 39 40
    end

    def retrieve_from_cache
      record = Rails.cache.read(cache_key)
      ensure_cache_setup if record.present?
41

42
      record
43 44 45 46 47 48 49
    end

    def current
      cached_record = cached
      return cached_record if cached_record.present?

      current_without_cache.tap { |current_record| current_record&.cache! }
50 51 52 53 54 55
    rescue => e
      if Rails.env.production?
        Rails.logger.warn("Cached record for #{name} couldn't be loaded, falling back to uncached record: #{e}")
      else
        raise e
      end
56 57 58 59 60 61 62 63 64 65
      # Fall back to an uncached value if there are any problems (e.g. Redis down)
      current_without_cache
    end

    def expire
      Rails.cache.delete(cache_key)
    rescue
      # Gracefully handle when Redis is not available. For example,
      # omnibus may fail here during gitlab:assets:compile.
    end
66 67 68 69 70 71

    def ensure_cache_setup
      # This is a workaround for a Rails bug that causes attribute methods not
      # to be loaded when read from cache: https://github.com/rails/rails/issues/27348
      define_attribute_methods
    end
72 73 74
  end

  def cache!
75
    Rails.cache.write(self.class.cache_key, self, expires_in: 1.minute)
76 77
  end
end